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GANGSTER right to repair Testimony by Tarah Wheeler of Securepairs

GANGSTER right to repair Testimony by Tarah Wheeler of Securepairs

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The Flexible Permanence of Copper Tape Circuits

Somewhere between shoving components into a breadboard temporarily and committing them to a piece of protoboard or a PCB lies the copper tape method. This flexible Manhattan-style method of circuitry formed the basis for [Bunnie Huang]’s Chibitronics startup, and has since inspired many to stop etching boards and start fetching hoards of copper tape.

[Hales] hit the ground running when he learned about this method, and has made many a copper tape circuit in the last year or so. He offers several nice tips on his site that speak from experience with this method, and he’ll even show you how to easily work an SMD breakout board into the mix.

Generally speaking, [Hales] prefers plywood as the substrate to paper or cardboard for durability. He starts by drawing out the circuit and planning where all the tape traces will go and how wide they need to be. Then he lays out copper traces and pads, rubs the tape against the substrate to make it adhere strongly, and reinforces joints and laps with solder before adding the components. As you can see, copper tape circuits can get pretty complicated if you use Kapton tape as insulation between stacked layers of traces.

Copper and Kapton (polyimide) tape are just two of the many useful tapes you may not be aware of. Stick with us a moment and check out [Nava Whiteford]’s exploration of various adhesive marvels.


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New Part Day: Arduino Goes Pro with the Portenta H7

The Consumer Electronics Show in Las Vegas is traditionally where the big names in tech show off their upcoming products, and the 2020 show was no different. There were new smartphones, TVs, and home automation devices from all the usual suspects. Even a few electric vehicles snuck in there. But mixed in among flashy presentations from the electronics giants was a considerably more restrained announcement from a company near and dear to the readers of Hackaday: Arduino is going pro.

While Arduino has been focused on the DIY and educational market since their inception, the newly unveiled Portenta H7 is designed for professional users who want to rapidly develop robust hardware suitable for industrial applications. With built-in wireless hardware and the ability to run Python and JavaScript out of the box, the powerful dual-core board comes with a similarly professional price tag; currently for preorder at $99 USD a pop, the Portenta is priced well outside of the company’s traditional DIY and educational markets. With increased competition from other low-cost microcontrollers, it seems that Arduino is looking to expand out of its comfort zone and find new revenue streams.

That’s a Lot of Pins

The Portenta H7 is obviously a far cry from the relatively dinky 8-bit Arduinos that we’ve all got filling up our parts drawers. Developed for high performance edge computing applications, the new board is powered by a 32-bit STM32H747XI that utilizes both an ARM Cortex M7 and an M4 running at 480 MHz and 240 MHz respectively. The two cores can work independently, allowing for example one core to run interpreted Python while the other runs code compiled in the Arduino IDE. When they need to work together, the cores can communicate with each other via a Remote Procedure Call (RPC) mechanism.

New Part Day Arduino Goes Pro with the Portenta H7
The new 80-pin connectors on the Portenta

Outwardly, the new board doesn’t look far removed from the modern Arduino form factor we’re used to. The USB connector has been upgraded to a Type-C, but the Portenta still retains the dual rows of pads ready for hand-soldered headers — that’s their more recent pinout that they call the Arduino MKR form factor.

If you look on the back of the board however, you’ll see that they’ve added two 80-pin high density connectors. According to the product page, these are intended to allow the Portenta to simply be plugged into a device as a removable module. The idea being that devices in the field can easily have their Portenta swapped out for an upgraded model. Some digging into the product page documentation section turns up a schematic that lists the connectors as Hirose DF40C-80DP-0.4V(51).

The base model Portenta features 8 MB SDRAM and 16 MB NOR flash, but it can be custom ordered with up to 64 MB of memory and 128 MB of flash should you need it. It’s also possible to delete various interfaces from the board when ordering, so if you don’t want network connectivity or the NXP SE050C2 crypto chip, they can simply be left off. However as of this writing it is unclear as to what minimum order quantity is necessary to unlock this level of customization, or or how much these modifications will change the unit cost.

Year of the Arduino Desktop?

The Portenta Carrier Board

The Portenta H7 is an impressive enough piece of hardware on its own, but when it’s plugged into the optional Carrier Board, things really start to get interesting. The Carrier Board provides full size connectors for all of the onboard peripherals, and according to documentation, turns the Portenta into an eNUC-class embedded computer. There’s even support for DisplayPort to connect a monitor, and miniPCI for expansion cards.

With a fully loaded Portenta H7 slotted into the Carrier Board, it would seem you have the makings of a low-power ARM “desktop” computer. Albeit one that wouldn’t outperform the Raspberry Pi Zero, and which costs several times more.

The Arduino press release and product page doesn’t make any mention of what kind of software or operating system said computer would run, so presumably that’s left as an exercise for the customer. While not particularly well suited to it, the ARM Cortex-M family of processors is capable of running the Linux kernel, so spinning up a “real” OS image for it should be possible. Of course with a maximum of just 64 MB of RAM, you’ll want to keep your performance expectations fairly low.

Where Does Portenta Fit?

We can’t even speculate what a maxed out Portenta would cost, and there’s no pricing or release date for the Carrier Board. But even at $99, the base model Portenta H7 would be a tough sell for hackers and makers who are used to buying dual-core ESP32 boards at 1/10 of the price, or the Teensy 4.0 which has a 600 MHz Cortex-M7 at 1/4 of the price. Which is fine, since this board isn’t intended for the traditional core Arduino audience.

Seeing the carrier board, we can’t help but notice some parallels here with the Raspberry Pi Compute Module. With connections broken out to a SODIMM header, the idea of the Computer Module was to help bridge the gap between the DIY community and the commercial one by offering up a Raspberry Pi in a more rugged form factor that would be easier to integrate into end-user products. But since it wasn’t any cheaper than the stock Pi, there wasn’t a whole lot of incentive to switch over. We haven’t seen consumer products advertising “Raspberry Pi Inside!” so it’s hard to tell if there has been any meaningful adoption from industry.

One has to wonder why any company that has the resources to integrate such an expensive board into their products wouldn’t just come up with their own custom design around the Portenta’s STM32H747XI chip, which even in single quantities, can currently be had for less than $15. The difference may end up coming down to the world-renowned community that surrounds the Arduino brand, and the company’s efforts to modernize their toolchain.


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OWON Oscilloscope Teardown

We sympathize with [learnelectronic’s] statement: “I’m ashamed. I may have bought another oscilloscope.” We get it and we enjoyed watching him tear down the OWON SDS1102. (Video, embedded below.) As you might guess, this is a 100 MHz, two-channel scope, and very similar to many other Chinese scopes you can get inexpensively.

The last ten minutes are so of the video below shows him removing the case. There’s only three little boards inside. One is clearly a power supply. The other two don’t have much on them. There’s a tiny RF shield over one part of the board, so you assume that’s the input section.

The larger board looks like it just mounts the user interface controls. The central board appears to have all the front end and microprocessor components. It is amazing how little there is to see.

The scope runs about $250 or so, new. Like most scopes in this price class it has a relatively small screen, and an 8-bit front end. The claimed sample rate is 1GS/s. However, the screen is larger than a Rigol DS1102E, which is pretty comparable and is about $50 more than the OWON.

We’ve asked readers to help us pick a cheap scope, and found that everyone has their own opinion. The last time we looked at an OWON scope, it was a confusing digital scope impersonating an analog one.


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Automate Your Life with Node-RED (Plus a Dash of MQTT)

For years we’ve seen a trickle of really interesting home automation projects that use the Node-RED package. Each time, the hackers behind these projects have raved about Node-RED and now I’ve joined those ranks as well.

This graphic-based coding platform lets you quickly put together useful operations and graphic user interfaces (GUIs), whether you’re the freshest greenhorn or a seasoned veteran. You can use it to switch your internet-connected lights on schedule, or at the touch of a button through a web-app available to any device on your home network. You can use it as an information dashboard for the weather forecast, latest Hackaday articles, bus schedules, or all of them at once. At a glance it abstracts away the complexity of writing Javascript, while also making it simple to dive under hood and use your 1337 haxor skills to add your own code.

You can get this up and running in less than an hour and I’m going to tackle that as well as examples for playing with MQTT, setting up a web GUI, and writing to log files. To make Node-RED persistent on your network you need a server, but it’s lean enough to run from a Raspberry Pi without issue, and it’s even installed by default in BeagleBone distributions. Code for all examples in this guide can be found in the tutorial repository. Let’s dive in!

What It Is

Node-RED is a graphical programming language built on Node.js. It implements a server and runs what are called “Flows”: programs based on Javascript. Why would you want to run a server-side IDE for your programs? Because Node-RED also makes it dead simple to spin up web apps and use them as your online information and control system.


To make your Node-RED programs persistent you do need a server, however, if you just want to play for now you can run locally. Your server can be as simple as installing the platform on a Raspberry Pi or an always-on computer on your LAN. Prerequisites include Node.js and npm (the Node.js package manager) which on a Linux system are an easy install.

sudo apt install nodejs

Now we can install Node-RED and, to follow the examples below, you should also install the dashboard package:

npm install node-red
npm install node-red-dashboard

To run locally you can just type node-red in the terminal. However, the more eloquent way to run this is as a systemd service. Copy the contents of the nodered.service file to /etc/systemd/system/nodered.service and update the User, Group, and WorkingDirectory variables in that file to match an actual user on your system. With that in place, just enable and start the service. It will now restart on a crash or system reboot from here on out.

systemctl enable mqtt_porchlight.service
systemctl start mqtt_porchlight.service

You can now load up the Node-RED IDE simply by visiting localhost:1880 in a web browser.

Hello World

The simplest thing to do as your first “flow” in Node-RED is: click button, get timestamp. To make the image above I did nothing more than drag the “Inject” and “Debug” nodes from the left column into the center, then drag the line that connects the two nodes. You need to click the “Deploy” button on the upper right any time you make changes, and then clicking the button hanging off the left side of the inject node, which has the “timestamp” label by default, to spit out the time in the debug window. Click the bug icon in above the right window if you’re not seeing the debug output.

This example isn’t very useful, but that’s not the point of Hello World code. This drives home the power of the graphical code system. What’s also interesting is that flows can be exported as json files. Here’s what this Hello World looks like and it can be imported to your own Node-RED installation.

        "disabled": false,
        "id": "ff177395.3cf468",
        "info": "",
        "label": "Hello World",
        "type": "tab"
        "crontab": "",
        "id": "1c6883be.759c24",
        "name": "",
        "once": false,
        "onceDelay": 0.1,
        "payload": "",
        "payloadType": "date",
        "repeat": "",
        "topic": "",
        "type": "inject",
        "wires": [
        "x": 200,
        "y": 140,
        "z": "ff177395.3cf468"
        "active": true,
        "complete": "false",
        "console": false,
        "id": "1fec91a8.ab7156",
        "name": "",
        "tosidebar": true,
        "tostatus": false,
        "type": "debug",
        "wires": [],
        "x": 370,
        "y": 140,
        "z": "ff177395.3cf468"

MQTT Quickstart

Automate Your Life with Node RED Plus a Dash of MQTT

Node-RED feels like it’s made specifically to be used with MQTT, the popular Internet of Things protocol for which Elliot Williams has written a fantastic guide. It feels that way because an MQTT client is built in and most of the nodes have “topics” as well as message payloads which is all you really need to communicate with an MQTT broker.

As you can see above, I’m doing the exact same inject/debug trick but now I’ve dragged an “mqtt in” and “mqtt out” node from the “Network” column of possible nodes.

Automate Your Life with Node RED Plus a Dash of MQTT
Automate Your Life with Node RED Plus a Dash of MQTT

There’s slightly more setup here as we need to choose an MQTT server and select a topic to publish to and listen for. But the interface makes this very easy, just double-click one of the MQTT nodes. Here I’m using the mosquitto test server ( the topic Hackaday/nodered/test. Just realize that anyone looking at messages on that server can see this and if you use the exact same topic you may see other readers sending test messages. Node-RED can actually be used as an MQTT broker as well.

Try double-clicking the inject node and changing the payload from timestamp to a string and you can send your own custom messages. For the most part I find it easy to find my way around Node-RED and playing with settings is low-effort. Just make sure to hit the deploy button — your changes won’t actually be in place until you do.

Web Gui Hello World

Automate Your Life with Node RED Plus a Dash of MQTTLet’s get to the really exciting part of Node-Red, the ability to spin up a web app with very little effort.

Here you can see a smartphone displaying our app. The only really useful part here is the button. Click it and you’ll get “Hello Hackaday!” in the debug window of Node-RED as seen above. All it took to create this page was to install the dashboard package for Node-RED and then drag a button onto the canvas. Once deployed, your web app will be located at localhost:1880/ui

Installation of the package is a simple one-liner:

npm install node-red-dashboard

Dragging the button onto the canvas and hooking it to a debug node is also simple, but you need to do just a bit of configuration. Double-clicking on the button node you can change the payload to affect what message is sent to the debug window, but you also need to set a Group, and within the group edit dialog you’ll need to set a Tab. This affects the web app, with Groups organizing blocks on each page of the web app, and Tabs selecting different pages from the hamburger menu at the upper left. You can name groups and tabs however you like.

Let’s Build a Web App!

Enough with the Hello World code, let’s build something useful. I’ve been using Node-RED for a month or so and have built up a couple of useful apps, one interacts with my MQTT broker to control and monitor my front porchlight, the other I use as a simple button-press to keep track of the days I exercise. Let’s build up the exercise app bit by bit because there’s more to it than merely sending MQTT packets back and forth.

Here is the current state of the exercise app, which includes a button that records today’s date to a log file and a gauge that reads the log file to display how many of the last seven days have included exercise. Let’s build it up one block at a time.

GUI Button Writing to Files

This is where the flow begins. It consists of a button from the Dashboard package that sends a timestamp when clicked. This message will be logged to two “file” nodes, the first is exerciselog-raw.txt which simply records one UNIX timestamp for each line. That’s not human readable, so the second file node has a function node which translates the timestamp using the following JavaScript snippet. There’s a bit of magic in there to make sure the month and day are always two digits.

var date;
date = new Date();
var year = date.getFullYear();
var month = date.getMonth();
month = (month < 9 ? '0' : '') + (month+1)
var day = date.getDate();
day = (day < 10 ? '0' : '') + day
msg.payload = year + '-' + month + '-' + day;
return msg;

Adding a User Notification

Automate Your Life with Node RED Plus a Dash of MQTT
Automate Your Life with Node RED Plus a Dash of MQTT

The button works as expected, but it gives no feedback to the user. To improve upon this I added a notification node from the dashboard package. It is connected after the file node to confirm that the date had been written to the log file.

Reading a File, Displaying Data, Refreshing at Startup

This last part of the flow uses the tan “file in” node to read UNIX timestamps from the raw log file and displays it on the teal “gauge” node from the dashboard package. It is activated by two different triggers, one updates after a new date is written to the log files. The other is the lavender “inject” node which has an “index once after n seconds” option to populate the initial data when Node-RED starts.

The gauge is just looking for a number to populate and this is fed by a function node (I called it Magic). The following code reads in the logfile as an array, figures out the UNIX date code for seven days ago, and then iterates back through the last seven timestamps in the log file.

//Turn incoming timestamps log into an array:
var exercisearray = msg.payload.split("\n");
if (exercisearray.slice(-1)[0] === "") exercisearray.length = exercisearray.length-1

//Get timestamp for week ago to compare against
var thismorning = new Date()
var sixdays = 1000*60*60*24*6
var oneweekago = thismorning.getTime()-sixdays

//Iterate and count past week of exercise
var count = 0
var secondsinday = 60*24*7
for (var i=1; i<8; i++) {
  if (i>exercisearray.length) break;
  var testval = parseInt(exercisearray.slice(-i)[0]);
  if (testval >= oneweekago) ++count;

//Store our answer as the payload and pass along
msg.payload = count;
return msg;

Give Node-RED a Try!

Automate Your Life with Node RED Plus a Dash of MQTTOne of my first concerns with the platform was version control but that’s available too. There is git integration built-in called Node-RED projects but it’s not enabled by default. I’m not accustomed to using a GUI for git, but then again I’m not accustomed to graphical programming interfaces so it doesn’t hurt to try something new.

The examples I’ve shown here are really the tip of the iceberg. Look around and you’ll find a ton of enthusiasm for Node-RED which translates to incredible flows and awesome web apps. For instance, I’ve been reading Scargill’s Tech Blog for years and there you’ll find a ton examples of what can be accomplished. Here we see Scargill’s thermostat control panel that has all kinds of customization to give it a special look. Finding examples that you like isn’t hard, and copying their code is even easier.

You can easily pick up Node-RED in an afternoon and end up with something useful. For those who want to spend more time, the sky’s the limit. If you have any kind of home automation, it’s something you must try as it unlocks the ability for anyone on your LAN to access information and control without installing an app. You can easily pull a disused smartphone out of the drawer and turn it into a dedicated control panel, something I did for the image at the top of this article with the help of an Android app called Fully Kiosk Browser Lockdown for a true fullscreen browser experience not provided by Chrome or Firefox for Android. Give it a try with your own surplus gear!



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Lego Drone Finally Takes Off

We were concerned when we saw [Brick Experiment Channel] test a drone propulsion pod made with Lego. After all, the thrust generated was less than the weight of the assembly. But a few tweaks got enough lift to overcome the assembly weight, as you can see in the video below.

The next step was to build three more pods and add some lightweight avionics and a battery. The first flight was a little dicey because the sensor orientation was off. Then there was some more software tuning before things really got airborne.

Judging from the nearby curtains, the drone puts out quite a bit of wind. However, it still needed a little more power from a bigger battery pack. It doesn’t look like the bird is a joy to fly, but it is impressive to see a bunch of Lego flying around the house. Granted the flight controller, the radio, and the battery aren’t Lego, but it looks like everything else is.

We aren’t sure we would recommend trying this project, but if you do, there is a bill of materials at the end of the video. The total cost was about $500 and you can get a pretty good commercial drone for that price. Still, the thrill of it would be worth something.

We’ve seen someone selling a kit to make Lego drones. If you’d rather stay on the ground, how about a monowheel?


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Tetraethyl Lead: The Solution To One, And Cause Of Many New Problems

From the 1920s until the 1970s, most gasoline cars in the USA were using fuel that had lead mixed into it. The reason for this was to reduce the engine knocking effect from abnormal combustion in internal combustion engines of the time. While lead — in the form of tetraethyllead — was effective at this, even the 1920s saw both the existence of alternative antiknock agents and an uncomfortable awareness of the health implications of lead exposure.

We’ll look at what drove the adoption of tetraethyllead, and why it was phased out once the environmental and health-related issues came into focus. But what about its antiknock effects? We’ll also be looking at the alternative antiknock agents that took its place and how this engine knocking issue is handled these days.

It’s a Matter of Octane

In an internal combustion engine (ICE), ideally the air-fuel mixture that gets injected into a cylinder will detonate at the perfect moment where the flame front will travel outwards from the point of ignition, with every bit of the air-fuel mixture burning up fully. This will allow for maximum use of the energy in the fuel mixture, while causing a clean stroke of the piston.

In reality, however, pockets of this fuel-air mixture will detonate before the flame front reaches them. These so-called ‘cool flames’ occur because of the compression by the piston combined with slight unevenness in the mixture, causing additional pressure waves in the cylinder. This raises the cylinder pressure and causes the typical metallic pinging noise that is indicative of engine knocking. Depending on how many of these pockets detonate outside of the spark plug’s flame front, the result may be increased wear on components, or even their outright destruction.

Hereby the octane rating of the fuel is crucial, as it essentially determines at which compression level the fuel will detonate (without spark). High octane fuels thus do burn less easily, but allow for far higher levels of compression, which effectively produces more power. In contrast, diesel engines require lower octane fuels, as they only compress air, with the fuel being injected at the end of the compression cycle, with the heat from the compressed air detonating the fuel.

Time to Knock It Off

There are fortunately a number of ways to prevent this premature detonation effect. These include:

  • Using a fuel with a higher octane rating.
  • Adding more fuel to the air-fuel mixture.
  • Reducing the compression level in the cylinder.
  • Reducing the load on the engine.

You can choose the first point by using a so-called antiknock agent, a chemical that raises the octane rating of the fuel by raising the temperature and pressure at which auto-ignition occurs. Tetraethyl lead (TEL) is one example of such an agent. Its chemical formula is (CH3CH2)4Pb.

Inside the engine’s cylinders, the function of TEL is to quench the spontaneous ignitions that occur outside of the flame front by dealing with the pyrolized radicals that would otherwise sustain the chain reaction of the cool flame. Here the lead is the actual reactive agent, while the rest of the TEL serves to allow it to dissolve into gasoline (courtesy of its alkyl groups).

As the TEL is burned, it produces carbon dioxide, water and lead:

(CH3CH2)4Pb + 13 O2 → 8 CO2 + 10 H2O + Pb

The lead can further react with oxygen to form lead(II) oxide:

2 Pb + O2 → 2 PbO

Left alone, the lead and lead(II) oxide would accumulate inside the engine and destroy it. To prevent this, lead-scavengers such as 1,2-dibromoethane and 1,2-dichloroethane are added to form lead(II) bromide and lead(II) chloride respectively (unfortunately neither are as pretty as lead(II) iodide). These compounds are easily removed from the engine during normal operation, from where they’d be released into the environment.

The Competition

In addition to lead, two other substances were known to increase the octane rating of gasoline fuel: ethanol (C2H6O) and benzene (C6H6). For ethanol this octane rating raising property is due to ethanol being suitable as a complete (albeit more expensive) replacement for gasoline fuel. As ethanol has by default a higher octane rating than most gasoline fuels, mixing a percentage of ethanol into gasoline fuel causes the latter to have a higher octane, which achieves the desired antiknocking effect.

When adding lead to gasoline was a plus. (Plazak, CC-BY-3.0)

Benzene is a hydrocarbon which appears naturally in crude oil. It’s present in gasoline as a result, where it’s also responsible for the characteristic sweet smell around gasoline refueling stations. Although now usually kept at less than 1% in gasoline due to the carcinogenic properties of benzene, before TEL’s introduction in the 1920s as a fuel additive, benzene was regarded as a good antiknock agent as it too raised the octane rating. By the 1950s TEL had virtually replaced benzene as antiknock agent.

Ethanol can be produced from oil (ethylene), as well as from biomass (sugar cane, corn, etc.). It is however a fuel type that has only seen widespread popularity since the 1970s. TEL had the benefit over ethanol as an antiknock agent that only a small amount would be needed to have the same effect, yet at similar cost. TEL however also had the additional benefit that its use as fuel-additive could be patented.

TEL Fallout

Ultimately history shows us that TEL would prevail over benzene and ethanol, with ethanol only making a resurgence in the 1970s during the phase-out of TEL. As information uncovered over the past decades shows, the reason for this was a deliberate strategy by the companies behind the Ethyl partnership (General Motors, ESSO and DuPont) to bury the science about the well-known harmful effects of lead, the expected blood serum lead levels from adding TEL to gasoline and the expected effects on the environment.

As this 2005 paper by William Kovarik (PDF) summarizes, the use of ethanol as an antiknock agent was commonplace by the time that TEL was introduced, but over the decades, the misinformation campaign by Ethyl was so effective that people came to believe that TEL was the only antiknock agent available. In the end it would take fifty years of research, as well as scientific, court and regulatory challenges to produce evidence about the harmful effects of TEL that were so damning that leaded gasoline was phased out in the 1970s in the US, though not without Ethyl first suing the Environmental Protection Agency (EPA).

Among one of the effects noted by researchers of the effects of increased lead levels in blood serum was that of a sharp negative effect on the developing brain, leading to a lower IQ, poor impulse control and troubles at school. Later studies introduced the lead-crime hypothesis, which links the rise in violent crime since the 1930s and the sharp drop-off in the early 1990s with the exposure of children to high blood serum lead levels, which would have impaired brain development.

Although the Ethyl corporation still exists today, the use of TEL in gasoline has been essentially reduced to zero, aside from use in avionics fuel, antique cars, and so on. As the use of TEL is incompatible with catalytic converters due to lead being a catalyst poison, the requirement of adding a catalytic converter to new cars in the late 1970s US made the demise of TEL for cars a certainty. Europe, Asian nations and so on also phased out TEL until today only one plant in the world still (legally) produces leaded gasoline.

Antiknock Strategies Today

Even though modern ICEs have hardened components that can withstand engine knocking without damage, and the mixing of ethanol into the gasoline fuel is becoming ever more commonplace, other antiknock agents are still around, with methylcyclopentadienyl manganese tricarbonyl (MMT, (C5H4CH3)Mn(CO)3) having been used for years in a number of countries.

Ferrocene (Fe(C5H5)2) is also used as a fuel additive, used as an alternative to TEL, such as for use in antique cars. Increasing the amount of 2,2,4-trimethylpentane (iso-octane, also a petroleum product) in gasoline serves to reduce the knocking, as was originally discovered by Graham Edgar in 1926. Iso-octane forms the 100 point on the octane rating scale.

In addition to fuel additives, modern digitally controlled gasoline engines have built-in mechanisms that detect and control engine knocking, by adjusting the ignition timing and pressure. This allows for the engine to automatically adjust itself to fuels with different octane ratings. This of course comes with its own set of challenges, as for example this 2017 paper by Petyon Jones et al. titled “Stochastic Simulation and Performance Analysis of Classical Knock Control Algorithms” details.

Just A Historical Footnote

It’s interesting to consider these revelations and new innovations in light of the transition of the car industry from the internal combustion engine to electric motors, which do not have any of these issues. Free from the stigma of leaded gasoline and its combustion products, it will be interesting to see how we will regard this chapter in human history fifty years from now.

By then not having regenerative braking would probably seem beyond quaint, as would be the ritual of weekly (or daily) refueling or recharging. Maybe the issue of fine particulate dust from tires and brake disks will have become the next environmental issue.

[Main image source: Tetraethyl Lead by David Brodbeck CC-BY 2.0]


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What To Know When Buying Chips That Haven’t Been Made For Three Decades

Those of us who have worked with vintage sound generator chips such as the Yamaha FM synthesizers in recent years have likely run into our own fair share of “fake” or “remarked” chips, sometimes relabeled to appear as a chip different than the die inside the packaging entirely. [David Viens] from Plogue has finally released his findings on the matter after 3 years of research.

The first thing to determine is in what way are these chips “fake”? Clearly no new YM2612’s were manufactured by Yamaha in 2015, but that doesn’t mean that these are simply unlicensed clones put out by another die factory. [David] explains how these chips are often original specimens sourced from recycled electronic waste from mostly environmentally unsafe operations in China, which are then reconditioned and remarked to be passed as “new” by resellers. Thankfully, as of 2017, he explains that most of these operations are now being shut down and moved into an industrial park where the work can be done in a less polluting manner.

The next thing that [David] dives into is how these remarked chips can be spotted. He explains how to use telltale signs in the IC packaging to identify which chip plant produced them, and visible indications of a chip that has been de-soldered from a board and reconditioned. There are different ways in which the remarking can be done, and sometimes it’s possible to undo the black-top, as it’s called, and reveal the original markings underneath with the simple application of acetone with a cotton swab.

We’ve talked about fake chips and how they can lead to hardware failure here before, but in the case of chips like these which aren’t manufactured anymore, we’re not left with much choice other than FPGA or software reimplementations. Check out [David]’s 40-minute look into these chips after the break.

[Thanks Greg Kennedy for the tip!]


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One ESP8266, One Battery, One Year… And Counting.

There are times when a sensor is required that does its job without the need for human attention over a long period, and for those applications a minimal power drain is a must. [Dave Davenport] had an EPS8266-based moisture sensor, and became disappointed in having to replace its AA batteries every few months. With an 18650 Li-ion cell and a bunch of power-saving tricks that time has been extended so far to over a year and still going, so he’s written a blog post detailing how he did it.

Some of his techniques such as turning off the sensor or using a better LDO regulator than the stock Wemos one are straightforward. Others though are unexpected, such as using the memory associated with the on-board RTC to store the WiFi connection info and channel number during sleep. The normal ESP8266 connection sequence involves a network scan, by hanging onto what it found last time the extra time and thus power expended by it can be avoided. Similarly switching from a DHCP lease to a fixed IP address cuts the time the device waits for a lease and thus the time it has to stay awake.

We might not all have ESP8266 moisture sensors to build, but we’re many of us on a quest to sip less power in our projects. Let us help you with a previous sojourn into that arena.

ESP8266 image: connorgoodwolf [CC BY-SA 4.0].


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Camcorder Viewfinder Converted to Diminutive Vector Display

We generally cast a skeptical eye at projects that claim some kind of superlative. If you go on about the “World’s Smallest” widget, the chances are pretty good that someone will point to a yet smaller version of the same thing. But in the case of what’s touted as “The world’s smallest vector monitor”, we’re willing to take that chance.

If you’ve seen any of [Arcade Jason]’s projects before, you’ll no doubt have noticed his abiding affection for vector displays. We’re OK with that; after all, many of the best machines from the Golden Age of arcade games such as Asteroids and Tempest were based on vector graphics. None so small as the current work, though, based as it is on the CRT from an old camcorder’s viewfinder. The tube appears to be about 3/4″ (19 mm) in diameter, and while it still had some of its original circuitry, the deflection coils had to be removed. In their place, [Jason] used a ferrite toroid with two windings, one for vertical and one for horizontal. Those were driven directly by a two-channel push-pull audio amplifier to make patterns on the screen. Skip to 15:30 in the video below to see the display playing [Jerobeam Fenderson]’s “Oscilloscope Music”.

As much as we’d love to see a tiny game of Battlezone played on the diminutive display, there’s only so much it can do. Maybe an analog version of this adorable digital oscilloscope would be possible?


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Particle Accelerators That Fit on a Chip

If you were asked to imagine a particle accelerator, you would probably picture a high-energy electron beam contained within a kilometers-long facility, manned by hundreds of engineers and researchers. You probably wouldn’t think of a chip smaller than a fingernail, yet that’s exactly what the SLAC National Accelerator Laboratory’s Accelerator on a Chip International Program (ACHIP) has accomplished.

The Stanford University team developed a device that uses lasers to accelerate electrons along etched channels on a silicon chip. The idea for a miniature accelerator has existed since the laser’s invention in 1960, but the requirement for a device to generate electrons made the early proof-of-concepts difficult to manufacture in bulk.

via Scientific American

The electromagnetic waves produced by lasers have much shorter wavelengths than the microwaves used in full-scale accelerators, allowing them to accelerate electrons in a far more confined space – channels can be shrunk to three one-thousandths of a millimeter wide. In order to couple the lasers and electrons properly, the light waves must push the particles in the correct direction with as much energy as possible. This also requires the device to generate electrons and transmit them via the proper channel. With an accelerator engraved in silicon, multiple components can fit on the same chip.

Within the latest prototype, a laser hits a grating from above the chip, directing the energy into a waveguide. The electromagnetic waves radiate out, moving with the waveguide until they reach an etched pattern that creates a focused electromagnetic field. As electrons move through the field, they accelerate and gain energy.

The results showed that the prototype could boost the electrons by 915 electron volts, equivalent to the electrons gaining 30 million electron volts over a meter. While the change is not on the scale of SLAC, it does scale up more easily since researchers can fit multiple accelerating paths onto future designs without the bulk of a full-scale accelerator. The chip exists as a single stage of the accelerator, allowing more researchers to conduct experiments without the need to reserve space in expensive full-scale particle accelerators.


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Make A Mean-Sounding Synth From Average Components

A while back, [lonesoulsurfer] stumbled upon a mind-blowing little DIY synth on YouTube and had to make one of his own. We don’t blame him one bit for that, ’cause we’ve been down that cavernous rabbit hole ourselves. You might want to build one too, after you hear the deliciously fat and guttural sounds waiting inside those chips and passives. Don’t say we didn’t warn you.

The main synth is built on five LM358 op-amps that route PWM through a pair of light-dependent resistors installed near the top. There are two more oscillators courtesy of a 40106 hex inverting Schmitt trigger, which leaves four more oscillators to play with should you take the plunge and build your own.

He didn’t just copy the guy’s schematic and call it good. He added [a 555-based arpeggiator that’s controlled with two homebrew optocouplers. These sound fancy and expensive, but can be bred easily at home by sealing an LED and an LDR inside a piece of black heat shrink tubing and applying a bit of PWM. With the flick of a toggle, he can bypass the momentary buttons and use the yellow knob at the top to sweep through the pitch range with a single input.

Although he doesn’t hold your hand through the build, [lonesoulsurfer] has plenty of nice, clear pictures of the process that nearly give a step-by-step guide. That plus the video demo and walk-through should get you well on your way to DIY synthville.

If this all seems very cool, but you’d really like to understand what’s happening as you descend into the rabbit hole, our own [Elliot Williams]’s Logic Noise series is an excellent start.


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A Slightly Bent ESP8266 Sensor Platform

The ability to get professionally manufactured PCBs, at least small ones, for dirt cheap has had a huge impact on the sort of projects we see around these parts. It’s getting to the point where experimenting with PCB enclosures is not only a way to make your next project stand out, but an economical choice.

Which is how this ESP8266 sensor gadget from [Josef Adamčík] got its unique “folded over” look. The top panel is where the microcontroller and headers for various sensors live, the bottom panel is home to the TP4056 USB charging module, and the center panel provides mechanical support as well as holds the single 18650 cell. Rather than close the whole thing up with a fourth panel, he decided to leave it open so the battery can easily be removed. Plus, of course, it looks cooler this way.

Could [Josef] have fit all his electronics on a single 100 x 100 PCB and then put the whole thing into a 3D printed enclosure? Well, sure. But that’s been done to death at this point, and besides, he was looking for an excuse to get more comfortable doing PCB design. We think it also makes for a considerably more visual appealing final product than simply taking the “normal” way out.

Currently [Josef] has an SHT21 humidity/temperature sensor and a BH1750 light sensor slotted into the headers on the top side of the device, but they could just as easily be swapped out with something else if you wanted to do something a bit more exciting. We notice that homebrew air quality monitors are becoming increasingly popular.

Building bespoke enclosures from PCBs is a fantastic trick that frankly we’d love to see more of. It’s somewhat of an artform in itself, but if you’re willing to put the effort in to do it right the results can be truly phenomenal.


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Better Controls For Your Chromecast Through CEC

Modern home cinema equipment is well-equipped with features for interoperability and convenience, but in practice, competing standards and arcana can make it fall over. Sometimes, you’ve gotta do a little work on your own to glue it all together, and that’s what led [Victor] to develop a little utility of his own.

ChromecastControls is a tool that makes controlling your home cinema easier by improving Chromecast’s integration with the CEC features of HDMI. CEC, or Consumer Electronics Control, is a bidirectional serial bus that is integrated as a part of the HDMI standard. It’s designed to help TVs, audio systems, and other AV hardware to communicate, and allow the user to control an entire home cinema setup with a single remote. Common use cases are TVs that send shutdown commands to attached soundbars when switched off, or Blu-Ray players that switch the TV on to the correct output when the play button is pressed.

[Victor]’s tool allows Chromecast to pass volume commands to surround sound processors, something that normally requires the user to manually adjust their settings with a seperate remote. It also sends shutdown commands to the attached TV when Chromecast goes into its idle state, saving energy. It relies on the PyChromecast library to intercept traffic on the network, and thus send the appropriate commands to other hardware. Simply running the code on a Raspberry Pi that’s hooked up to any HDMI port on a relevant device should enable the CEC commands to get through.

It’s a project that you might find handy, particularly if you’re sick of leaving your television on 24 hours a day because Chromecast never bothered to implement a simple CEC command on an idle timeout. CEC hacks have a long history, too – we’ve been covering them as far back as 2010!


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A Replica from WarGames, But Not the One You Think

Remember the WOPR from WarGames? The fictional supercomputer that went toe-to-toe with Matthew Broderick and his acoustic coupler was like a love letter to the blinkenlight mainframes of yesteryear, and every hacker of a certain age has secretly yearned for their own scaled down model of it. Well…that’s not what this project is.

The [Unexpected Maker] is as much a WarGames fan as any of us, but he was more interested in recreating the red alphanumeric displays that ticked along as the WOPR was trying to brute force missile launch codes. These displays, complete with their thoroughly 1980s “computer” sound effects, were used to ratchet up the tension by showing how close the supercomputer was to kicking off World War III.

The display as it appeared in the film.

Of course, most us don’t have a missile silo to install his recreated display in. So when it’s not running through one of the randomized launch code decoding sequences, the display doubles as an NTP synchronized clock. With the retro fourteen segment LEDs glowing behind the smoked acrylic front panel, we think the clock itself is pretty slick even without the movie references.

Beyond the aforementioned LEDs, [Unexpected Maker] is using a ESP32 development board of his own design called the TinyPICO. An associated audio “Shield” with an integrated buzzer provides the appropriate bleeps and bloops as the display goes through the motions. Everything is held inside of an understated 3D printed enclosure that would look great on the wall or a desk.

Once you’ve got your launch code busting LED clock going in the corner, and your illuimated DEFCON display mounted on the wall, you’ll be well on the way to completing the WarGames playset we’ve been dreaming of since 1983. The only way to lose is to not play the game! (Or something like that…)


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Raspberry Pi 4 and the State of Video Game Emulation

The modern ideal of pixel art is a fallacy. Videogame art crammed onto cartridges and floppy discs were beholden to the CRT display technology of their day. Transmitting analog video within the confines of dingy yellow-RCA-connector-blur, the images were really just a suggestion of on-screen shapes rather than clearly defined graphics. Even when using the superior RGB-video-over-SCART cables, most consumer grade CRT televisions never generated more than about 400 lines, so the exacting nature of digitized plots became a fuzzy raster when traced by an electron beam. It wasn’t until the late 90s when the confluence of high resolution PC monitors, file sharing, and open source emulation software that the masses saw pixels for the sharp square blocks of color that they are.

More importantly, emulation software is not restricted to any one type of display technology any more than the strata of device it runs on. The open-source nature of videogame emulators always seems to congregate around the Lowest Common Denominator of devices, giving the widest swath of gamers the chance to play. Now, that “L.C.D.” may very well be the Raspberry Pi 4. The single board computer’s mix of tinker-friendly IO at an astonishingly affordable entry price has made it a natural home for emulators, but at fifty bucks what options unlock within the emulation scene?

The Dubious Price Tag That’s  Still Quite Low, All-In

Raspberry Pi 4 with Thermometer
The raspberry pi 4 runs a little hot out of the box.

The technological gap between the Raspberry Pi 4 and its predecessor is sizeable. A 22% jump in clock speed, upwards of four times the RAM, and support for 4K resolution all while retaining the same footprint should not be undersold. Those advancements were coupled with a heightened 3A power requirement meaning extra cost as not just any PSU over USB-C will do. All those additional amps added up to a worryingly hot surface temperature anywhere from 50 to 80 °C on launch firmware. Even with updated firmware, any serious user will want an additional cooling solution in place. You will also shell out some clams for all the gaming accouterments: keyboard/gamepad, micro-HDMI cable, and flash storage. Ultimately the promise of an inexpensive emulation box fluctuates depending on the amount of pre-existing equipment. But even considering all of the add-ons, to have a dedicated gaming rig at this entry price is pretty incredible. The question is, what kind of gaming is possible?

When it comes to arcade game emulation on a Raspberry Pi, most users’ first stop is the RetroPie distribution. It provides a lightweight user interface that scales well on a variety of resolutions. RetroPie employs the use of advMAME v3.9 as its arcade machine emulation software. While plenty capable, advMAME is actually a port of MAME v0.108 which dates back to 2006. The bulk of emulators written in that time typically prioritized speed over accuracy in order to maintain playability, so the concept of a CRT filter or console chip-level cycle accuracy was hardly possible given the constraints of mid-2000s hardware. This example is not to denigrate any of the developers of advMAME or the RetroPie wrapper, but to point out that there is a cost to the relative convenience of a Raspberry Pi. If the proficiency of emulation is relegated to the era of the original Xbox, then why not use a Xbox instead? The rebuttal is simply two words… runahead mode. And the quad-core nature of the Pi 4 makes it particularly well suited for this.

Run (Kokiri) Forest, Run

For the uninitiated, Retroarch is a frontend that aggregates a large collection of emulation software and is part of retroPie. The development team behind Retroarch announced Raspberry Pi 4 support for a latency-reduction process known as runahead mode. Their description highlights the low-latency benefits of the effort: “The runahead feature calculates the frames as fast as possible in the background to rollback the action as close as possible to the input command requested.” Emulators can be resource intensive, soaking up all the available CPU horsepower and memory. Controller polling can fall out of sync with what is currently displayed on screen when a particular game sequence becomes more demanding. Things can get laggy.

Enabling Retroarch’s runahead mode on the select emulation cores for which it is available (Genesis Plus GX, Snes9x 2010, and VBA Next) can alleviate the input lag caused by the emulator itself.

Runahead Mode Process Flow
Process flow diagram of two-instance runahead mode in Retroarch.

When runahead mode is properly implemented on a Raspberry Pi 4, games control more-or-less as they did on the original hardware. This means losing a life in a run n’ gun the likes of Gunstar Heroes is solely due to user-error. On the other hand, turn based games in the vein of Final Fantasy are safe to play without runahead mode enabled. Those behemoths sure are patient folk.

It should be noted that this revolutionary feature is predicated upon being paired with a halfway decent LCD and wired gamepad/keyboard. Unfortunately, all the simultaneous instances of a game cannot overcome a poor pixel response time or a sub-par Bluetooth radio controller.

Optical Media Shifts Into View

For the first time in the Pi-lineage, there are multiple options for disc-based console emulators. Dreamcast, PSP, Saturn, and even PlayStation 2 cores via Retroarch v1.7.8 have all made their way onto Raspberry Pi 4. Granted the bulk of these systems do not run at full-speed quite yet, but there are some real overachievers still in their nascent beta forms. Specifically redream, a recently developed Sega Dreamcast emulator, has shown remarkable progress (video below) despite having no Raspberry Pi builds considered stable. Games play at or around sixty frames per second at a 720p resolution. The venerated Dolphin emulator (Gamecube/Wii) has even shown signs of promise running on the single board computer.

Beyond Gamecube, there are an array of arcade games that have only now been emulated due to their complexity and are not likely to run on a Raspberry Pi for years to come. Recreating the authentic 20th-century arcade experience may not be within reach in this form factor as more comprehensive emulators like the current iteration of MAME are simply too taxing to run currently. The yearly cadence of new Pi device revisions will prove difficult to retain developer’s attention, and further maturation of emulation software will only help alleviate a device’s lack of raw computing prowess. Runahead mode and access to previously inaccessible emulators certainly bolster the viability of the Raspberry Pi 4 as an all-in-one solution, though what’s most important is that these good ol’ games are being played at all.


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CircuitPython Now Working On Teensy 4.0

Python is often touted as a great language for beginner coders to learn. Until recently, however, it simply wasn’t a viable choice in the embedded space. That’s begun to change with projects like CircuitPython, and now it’s available on the Teensy 4.0!

This milestone is thanks in part to [arturo182], who did the ground work of getting CircuitPython to run on the iMX RT series of microcontrollers. This was built upon by [tannewt], who is the lead in charge of the CircuitPython project.

There are some bugs to work out; currently, the project is in a very early stage of development. [Paul Stoffregen], who heads Teensy development, has already pointed out that there needs to be allowance for the 4096 byte recovery partition in the Teensy 4.0’s storage, for example. Development continues at a rapid pace, and those with ideas about where the project should go can weigh in online.

It’s an exciting development, which brings easy Python development to one of the more powerful embedded development platforms on the market. We look forward to seeing many more projects take advantage of the power of the Teensy 4.0 moving forward. If you’re eager to see what can be done with CircuitPython, be sure to check out projects we’ve featured before. Video after the break.


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Node-RED Laser Shooting Gallery Goes Anywhere

When you think of a shooting gallery, you might envision a line of tin cans set up along a split-rail fence, or a few rows of ducks or bottles lined up at a carnival. But what do these have in common? You, standing in one spot, and shooting in the same general direction. You’re exposed! If those targets could shoot back, you’d be dead within seconds. Wouldn’t it be more fun if the targets were all around you in 360°? We think so, too.

So how could you possibly set up a shooting gallery this way? [Another Maker] already solved that problem for you with ESP32s and Node-RED (YouTube). Each target has an ESP32, a laser sensor, and an LED that lights up when the target is ready, and turns off once it’s been hit. They all make an enticing ‘shoot me’ sound that goes with their graphics, and a second mp3 plays upon direct hit.

The PVC gun houses an ESP8266, a laser module at the end of the barrel, and runs on a cylindrical USB battery slipped down in the secondary grip. [Another Maker] can spread the targets out far and wide, as long as they all stay in range of the localized WiFi access point.

The best part is that the Node-RED system is target-agnostic — it doesn’t care how many you have or how they’re made, and it can juggle up to 250 of them. Because of the way the target objects are programmed, it would be quite easy to add actuators that make them drop down or fall backward when hit. You could also implement [Another Maker]’s fantastic suggestion of hitting arcade buttons with NERF darts instead. Charge those lasers and fire at the break button to see the demo and walk-through video.

If you plan to knock the targets down or over in your implementation, you’ll want an easy way to reset them. Here’s a scrap-built shooting gallery that uses a windshield wiper motor to set ’em back up.

Via r/duino


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In Soviet Russia, Doorbell Rings You

We can imagine that the origin of the doorbell is truly ancient. if you lived in a cave, you probably had a stick and a rock nearby for people to get your attention without invading your cave. In 1817 a Scot named William Murdoch had a bell in the house that visitors rang via a compressed air system, but the electric doorbell had to wait until 1831. Since then, little has changed with the basic idea. [Erientes] — who lives in the Netherlands, not Russia — wanted a smarter doorbell. In particular, he’s read about older people being victimized by people who ring the doorbell for entry. So [Erientes] used a Raspberry Pi to make a doorbell that supports facial recognition.

The exercise is really more of an operations challenge than a technical one thanks to a high-quality Python library for face recognition powered by DLib. However, we did like the user interface aimed at non-technical users. The metaphor is a traffic light in which a red light means do not allow entry. The lights are buttons, so you can use them to whitelist or blacklist a particular person.

We could see this being coupled with a keypad to make a two-factor access control system. To unlock the door, you have to present your face and enter a code number. While it is true that the facial recognition system isn’t perfect, the chances that someone would learn your code and be able to duplicate your face well enough to fool the algorithm seems pretty slim.

If you want to play with the facial recognition online, you won’t need to install any software. That’s a great use of Jupyter. As for fooling facial recognition, maybe this project needs a bit more work.


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In Soviet Russia, Doorbell Rings You

We can imagine that the origin of the doorbell is truly ancient. if you lived in a cave, you probably had a stick and a rock nearby for people to get your attention without invading your cave. In 1817 a Scot named William Murdoch had a bell in the house that visitors rang via a compressed air system, but the electric doorbell had to wait until 1831. Since then, little has changed with the basic idea. [Erientes] — who lives in the Netherlands, not Russia — wanted a smarter doorbell. In particular, he’s read about older people being victimized by people who ring the doorbell for entry. So [Erientes] used a Raspberry Pi to make a doorbell that supports facial recognition.

The exercise is really more of an operations challenge than a technical one thanks to a high-quality Python library for face recognition powered by DLib. However, we did like the user interface aimed at non-technical users. The metaphor is a traffic light in which a red light means do not allow entry. The lights are buttons, so you can use them to whitelist or blacklist a particular person.

We could see this being coupled with a keypad to make a two-factor access control system. To unlock the door, you have to present your face and enter a code number. While it is true that the facial recognition system isn’t perfect, the chances that someone would learn your code and be able to duplicate your face well enough to fool the algorithm seems pretty slim.

If you want to play with the facial recognition online, you won’t need to install any software. That’s a great use of Jupyter. As for fooling facial recognition, maybe this project needs a bit more work.


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In Soviet Russia, Doorbell Rings You

We can imagine that the origin of the doorbell is truly ancient. if you lived in a cave, you probably had a stick and a rock nearby for people to get your attention without invading your cave. In 1817 a Scot named William Murdoch had a bell in the house that visitors rang via a compressed air system, but the electric doorbell had to wait until 1831. Since then, little has changed with the basic idea. [Erientes] — who lives in the Netherlands, not Russia — wanted a smarter doorbell. In particular, he’s read about older people being victimized by people who ring the doorbell for entry. So [Erientes] used a Raspberry Pi to make a doorbell that supports facial recognition.

The exercise is really more of an operations challenge than a technical one thanks to a high-quality Python library for face recognition powered by DLib. However, we did like the user interface aimed at non-technical users. The metaphor is a traffic light in which a red light means do not allow entry. The lights are buttons, so you can use them to whitelist or blacklist a particular person.

We could see this being coupled with a keypad to make a two-factor access control system. To unlock the door, you have to present your face and enter a code number. While it is true that the facial recognition system isn’t perfect, the chances that someone would learn your code and be able to duplicate your face well enough to fool the algorithm seems pretty slim.

If you want to play with the facial recognition online, you won’t need to install any software. That’s a great use of Jupyter. As for fooling facial recognition, maybe this project needs a bit more work.


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Run Java On An Amiga

In the modern world, we take certain tools for granted. High-level programming languages such as C or Python haven’t been around that long in the grand scheme of things, and Java has only existed since the ’90s. Getting these tools working on machines that predate them is more of a challenge than anything, and [Michael Kohn] was more than willing to tackle this one. He recently got Java running on a Commodore Amiga.

The Amgia predates Java itself by almost a decade, so this process wasn’t exactly straightforward. The platform has a number of coprocessors that were novel for their time but aren’t as commonplace now, taking care of such tasks such as graphics, sound, and memory handling. Any psoftware running on the Amiga needs to be in a specially formatted program as well, so that needed to be taken care of, even loading Java on the computer in the first place took some special work using a null modem cable rather than the floppy disk an Amiga would have used back in the day.

Loading Java on an antique Amiga is certainly a badge of honor, but [Michael] isn’t a stranger to Java and the Motorola 68000s found in Amigas. There’s a 68000 in the Sega Genesis as well, and we’ve seen how [Michael] was able to run Java on that too.


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Active Suspension R/C Car Really Rocks

When you’re a kid, remote control cars are totally awesome. Even if you can’t go anywhere by yourself, it’s much easier to imagine a nice getaway from the daily grind of elementary school if you have some wheels. And yeah, R/C cars are still awesome once you’re an adult, but actual car-driving experience will probably make you yearn for more realism.

What could be more realistic and fun than an active suspension? Plenty of adults will never get the chance to hit the switches in real car, but after a year of hard work, [snoopybg] is ready to go front and back, side to side, and even drift in this super scale ’63 Oldsmobile Dynamic 88 wagon. We think you’ll agree that [snoopybg] didn’t miss a detail — this thing makes engine noises, and there are LEDs in the dual exhaust pipes to simulate flames.

An Arduino reads data from a triple-axis accelerometer in real time, and adjusts a servo on each wheel accordingly, also in real time, to mimic a real car throwing its weight around on a real suspension system. If that weren’t cool enough, most of the car is printed, including the tires. [snoopybg] started with a drift car chassis, but even that has been hacked and drilled out as needed.

There are a ton of nice pictures on [snoopybg]’s site if you want to see what’s under the hood. We don’t see the code anywhere, but [snoopybg] seems quite open to publishing more details if there is interest out there. Strap yourself in and hold on tight, because we’re gonna take this baby for a spin after the break.

If this is all seems a bit much for you, but you’ve got that R/C itch again, there’s a lot to be said for upgrading the electronics in a stock R/C car.

Via r/duino


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Finally, A Real Set Of Gamecube Joycons

The Gamecube may not have sold as many units as its competitors in its day, but it maintains a cult fanbase to this day. Due largely to the Smash Bros. community, its controllers are still highly sought after. After the release of the Nintendo Switch, with plenty of fan renders around the place [Shank Mods] figured someone would create a set of Joycons with Gamecube controls. After waiting almost four years, he decided instead to do it himself.

The build begins with a Wavebird controller shell, chosen for its larger body, which is coincidentally the same height as the Switch. The shell was cut down the middle, and 3D printed components were created to attach Joycon mounting rails to the two halves of the controller. The large controller also has plenty of space inside, making it easy to fit all the Joycon components inside. Compatibility was a key aim of this build, so much attention was paid to make the Gamecube Joycons function properly with all Switch features. Extra buttons were added where necessary, and the formerly analog triggers were modified with plugs to match the solely digital operation of the Switch components.

It’s a project that had to overcome many hurdles, from mechanical redesigns to make everything fit, to figuring out the arcane electrical design of the Joycon hardware. The hard work paid off however, and [Shank Mods], along with a couple of talented community members, was able to create a beautiful piece of hardware. We’ve seen Gamecube-themed Joycons before, but this build really does take the cake. If you’ve instead modified the original Xbox controller to work with the Switch, be sure to let us know. Video after the break.


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The Way of the PCB Artist: How to Make Truly Beautiful Circuit Boards

Getting your own PCBs made is a rite of passage for the hardware hacker. Oftentimes, it’s a proud moment, and many of us choose to immortalise the achievement with a self-aggrandizing credit on the silk screen, or perhaps a joke or personal logo. However, as far as artistically customized PCBs go, the sky really is the limit, and this is the specialty of [TwinkleTwinkie], whose Supercon talk covers some of the pitfalls you can run into when working at the edges of conventional PCB processes. 

[TwinkleTwinkie]’s creations are usually badges of one type or other — they’re meant to be worn on a lanyard around your neck, as a pin, or as a decoration added to another badge. The whole point is the aesthetic, and style is just as important as functionality. With diverse inspirations like Futurama, Alice in Wonderland and the shenanigans of the GIF community, his badges blend brightly colored boards with a big helping of LEDs and artistic silkscreening to create electronic works of art.

Keeping PCB Fab Houses from Upsetting the Artwork

These days, PCB fab houses offer more choice than ever, in terms of silkscreens, soldermask colors, and other options.  However, fundamentally, their primary concern is to produce reliable, accurate, electronically functional boards — and it’s something that can cause problems for #badgelife hackers designing for more aesthetic reasons.

The Way of the PCB Artist How to Make Truly Beautiful Circuit Boards
On the left, a prototype, and on the right, a model with the black silkscreen part, showing how the LEDs appear dimmer.

[TwinkleTwinkie] ran into this very problem during the development of the Arc Badge, a piece designed to replicate the famous arc reactor from the Iron Man and Avengers films. The basic idea of the badge was to have a base PCB which carries all the hardware, along with a spacer, and then a third top layer consisting of a PCB which the LEDs were intended to shine through. The prototype board worked well, with the fab house producing it on 1.6mm thick FR4 with white silkscreen and red soldermask. For the final product, wanting something a little fancier, black silkscreen was chosen instead. Ordered through PCBWay, this necessitated using their “Advanced Production Fab”, and a longer lead time, but after a few weeks the boards were ready.

A comparison with the final, fixed part on the left and the black silkscreen part on the right. The final design allows much more light to pass through.

Unfortunately, despite looking great with the black silkscreen contrasting with the rich red soldermask, there was a problem. When [TwinkleTwinkie] asked for black soldermask, this also led to a change in FR4 material, to a different grade which was more opaque than the prototype board. This led to the LEDs showing up very dim, and spoiled the visual effect that was desired for the ArcBadge. The dimming was so significant that users would no longer get the glow-through effect when wearing the badge under a T-shirt, a la Tony Stark. It took comparison with the prototype to figure out what had happened. PCBWay had simply used a higher-grade material when switching to the black silkscreen. Given that PCBs are sold as electronic products, and not for their optical qualities, they hadn’t done anything wrong, per se – but regardless, the new boards weren’t fit for purpose.

Order, and Order, and Order Again

The solution was simple – the boards would need to be reordered. In order to guarantee the LEDs would shine through and be truly resplendent, precautions were taken. The final board switched back to white silkscreen. As an additional precaution, in case PCBWay kept using the new material, the new part was instead 0.8mm thick, allowing it to block less light.

The redesign left [TwinkleTwinkie] with 250 coasters to give out, but his commitment to giving his customers a quality product is commendable. Despite nobody outright making a mistake, the final product would have been a little disappointing had the redesign not taken place. The Arc Badge, as delivered, glows with the best of them, and we’re sure everyone involved is wiser for the experience!


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Habitable Exoplanets Hack Chat

Join us on Wednesday, January 15 at noon Pacific for the Habitable Exoplanets Hack Chat with Alberto Caballero!

Many of the major scientific achievements of the last 100 years or so have boiled down to problems of picking out a signal from the noise. Think about analyzing the human genome, for instance: we each have something like two meters of DNA coiled up inside each cell in our body, and yet teasing out the information in a single gene had to wait until we developed sufficiently sophisticated methods like PCR and CRISPR.

Similarly, albeit on the other end of the scale, the search for planets beyond our solar system wasn’t practical until methods and instruments that could measure the infinitesimal affect a planet’s orbit on its star were developed. Once that door was unlocked, reports of exoplanets came flooding in, and Earth went from being a unique place in the galaxy to just one of many, many places life could possibly have gotten a foothold. And now, the barrier for entry to the club of planet hunters has dropped low enough that amateur astronomers are getting in on the action.

Alberto Caballero is one such stargazer, and he has turned his passion for astronomy into an organized project that is taking a good, hard look at some of our nearest stellar neighbors in the hope of finding exoplanets in the habitable zone. The Habitable Exoplanet Hunting Project is training the instruments in 33 observatories around the globe on ten stars within 100 light-years, hoping to detect the faint signal that indicates an orbiting planet. They hope to add to the list of places worthy of exploration, both from Earth via optical and radio telescopes, and perhaps, someday, in person.

Join us on the Hack Chat with Alberto as we discuss the search for habitable exoplanets. We’ll explore the project’s goals, its successes thus far, and where it’s going in the future. We’ll also find out just what the amateur astronomer needs to get in on the action, and maybe even talk a little about why the search for “Earth 2.0” is so important.

join-hack-chatOur Hack Chats are live community events in the Hack Chat group messaging. This week we’ll be sitting down on Wednesday, January 15 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Kepler-442b image credit: Ph03nix1986 [CC-BY-SA]


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Anti-Bacterial Plastic Wrap Clings to Hope of Stopping Superbugs’ Spread

Researchers at McMaster University in Ontario have developed a plastic wrap that repels viruses and bacteria, including some of the scariest antibiotic-resistant superbugs known to science. With the help of a scanning electron microscope, the researchers were able to watch superbugs like MRSA and Pseudomonas bounce right off the surface.

The wrap can be applied to things temporarily, much like that stuff you wrestle from the box and stretch over your leftovers. It can also be shrink-wrapped to any compatible surface without losing effectiveness. The ability to cover surfaces with bacteria-shielding armor could have an incredible impact on superbug populations inside hospitals. It could be shrink-wrapped to all kinds of things, from door handles to railings to waiting room chair armrests to the pens that everyone uses to sign off on receiving care.

Everything bounces right off the surface, including that classic blue testing liquid. Image via SciTech Daily

According to the CDC, there are more than 2.8 million antibiotic-resistant infections reported in the United States each year, resulting in over 35,000 deaths. These superbugs are most prevalent and dangerous in hospitals and other medical settings like nursing homes, and they’re especially threatening to the weakened immune systems of chemo patients, dialysis patients and anyone undergoing surgery.

The superbug crisis pivots on the point that antibiotics are a double-edged sword. As they fight infection, they also weaken immune systems, which allows antibiotic-resistant bugs to proliferate in easily-won battlegrounds. Doctors have little choice but to use more toxic and potentially ineffective types of antibiotics to treat antibiotic-resistant infections. On top of everything else, these drugs are often more expensive.

One of the first lines of defense for avoiding large-scale superbug threats in the first place is protecting the food supply. This fantastic plastic could really beef up sanitation practices at food-packaging plants where salmonella and E. coli lurk.

Lotus leaves, close and closer. Images via Lotus Rock and William Thielicke (inset)

The Lotus Effect

The key to this antibacterial trampoline is in the surface topography. It’s made of of microscopic wrinkles meant to mimic the lotus effect — that repellent property of lotus leaves that makes water bead on their surface.

Lotus leaves are covered with tiny pointed bumps that disrupt the surface so much that water is unable to settle and spread out. The tips of these bumps are coated in a wax secreted by the plant that furthers its hydrophobic properties. They are often described as self-cleaning, because the beaded water droplets carry dirt particles away with them.

The researchers say they also treated their plastic wrap chemically “to further enhance its repellent properties”, though it’s unclear what chemical they’re talking about. Hopefully, it’s something innocuous that acts like wax.

Door knob on the Ribe Cathedral in Denmark. Image credit: Wolfgang Sauber CC BY-SA 3.0

Where Did All the Brass Door Knobs Go?

Our more experienced readers might recall that we already have a kind of antibacterial door knob technology, and it’s been around for quite a long time.

Copper, brass, and silver all exhibit the oligodynamic effect, which means they are slowly poisonous to bacteria. Many door knobs and public surfaces used to be made of brass to take advantage of the biocidal effect. This would only go so far in the hospital setting, because the effect takes several hours.

So why aren’t all door knobs still made of brass? Who can really say? Tastes change, brass tarnishes, and people forget about the oligodynamic effect. C’est la vie.

MRSA black light poster via The Independent

Resistance May Be Futile

At first blush, this special wrap sounds like something we’d want to put absolutely everywhere, like all public surfaces and our phones. MRSA and other antibiotic-resistant superbugs don’t exist solely within hospital walls, after all. But not all forms of bacteria are bad — in fact, plenty of good bacteria called gut flora lives in our intestines. It’s an important part of our immune system that keeps us from getting sick every single time we encounter a new pathogen. If every public surface was covered in this stuff, we couldn’t pick up germs nearly as well because they wouldn’t stick anywhere.

From a practical standpoint, this stuff is only going to be useful if that special surface can stand up to the wear and tear of hospital environments without being crushed or worn away. It would also have to survive the frequent, rigorous, and probably bleach-based cleaning routines. One little scratch or ding in the armor, and you have a disgusting little critter crevice crawling with superbugs.

Let’s say this stuff is everywhere ten or fifteen years from now. Is there a downside to repelling so much bacteria? Where will it all go? Will it gang up? Would it mean an increase in airborne bacteria? And what about that secret sauce chemical they treated the plastic wrap with to make it more repellent? Will we regret exposing ourselves to it?

That said, the researchers don’t intend for this stuff to be the answer to the superbug problem, just a weapon in the arsenal. It seems to us to be worth a shot to use it in medical facilities, but of course, time will tell.

Continue reading Anti-Bacterial Plastic Wrap Clings to Hope of Stopping Superbugs’ Spread

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3DBuzz Closes with a Final Gift

If you wanted to learn about creating modern computer games, 3DBuzz had some of the best tutorials around. In fact, some of the tutorials about C#, C++, Android, and math would be useful for anyone, while the ones about game art and modeling in Maya are probably mostly for game developers. While these were once available only by subscription, the company — now defunct — has left them available for download at no cost.

We don’t know enough about things like Blender and Maya to evaluate the material, but it is well regarded and the ones we do know something about seem very high quality. There are, for example, many videos about C++ and C# that are very professional and cover quite a few topics.

Topics include: AI programming,, Blender, iPhone and Android apps, C#, C++, Objective C, Python, OpenGL, HTML and JavaScript, Solidworks, Photoshop, GIMP, Unity, and several game engines like Unreal 4 and Doom 3. There are also quite a few classes on 2D and 3D art as well as related math like trig and vectors.

We don’t know how long the page will remain up, and it has an SSL issue, but to save you some time, here’s a quick way to grab all the ZIP files on a page:

wget -nc -r -np --span-host -l 1 -A zip --no-check-certificate

However, as you might expect, the site is overloaded, so expect to not get them all in one swoop. We were surprised they didn’t make them available as torrents. (Update: the site now says downloads are temporarily disabled, but a Reddit user did start a torrent that is missing two small files and a corrected torrent with all the files, but it may not have as many seeds.)

If you want to build games with less fuss, try this tool. Or, maybe you’d rather go old school.


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Why Do Resistors Have a Color Code?

One of the first things you learn in electronics is how to identify a resistor’s value. Through-hole resistors have color codes, and that’s generally where beginners begin. But why are they marked like this? Like red stop signs and yellow lines down the middle of the road, it just seems like it has always been that way when, in fact, it hasn’t.

Before the 1920s, components were marked any old way the manufacturer felt like marking them. Then in 1924, 50 radio manufacturers in Chicago formed a trade group. The idea was to share patents among the members. Almost immediately the name changed from “Associated Radio Manufacturers” to the “Radio Manufacturer’s Association” or RMA.  There would be several more name changes over the years until finally, it became the EIA or the Electronic Industries Alliance. The EIA doesn’t actually exist anymore. It exploded into several specific divisions, but that’s another story.

This is the tale of how color bands made their way onto every through-hole resistor from every manufacturer in the world.

Dots Then Bands

Why Do Resistors Have a Color Code
Ésistances anciennes annees 50 by François Collard, CC-BY-SA 4.0

By the late 1920s, the RMA was setting standards and one of them was the RMA standard for color-coding. The problem was that marking small components is difficult, especially back in the 1920s.

The solution was color bands, but not quite as we know them today. The standard for colors was the same, but the body of the resistor acted as the first band. Then there would be two or three other bands to show the rest of the value. In some cases, the third band was actually a dot. So the bulk of the resistor would be the first band color. The “tip” of the resistor would be the 2nd band and a dot would be the multiplier. Radios using this scheme started to appear in 1930. Here’s the color code chart from the 1941 Radio Today yearbook:

Why Do Resistors Have a Color CodeAds in that magazine promoting resistors were careful to note that they were RMA color-coded. The code soon extended to capacitors (condensers, in the contemporary parlance).

Why Do Resistors Have a Color CodeThe dot, as with printed piece of text on the cylindrical, might be hidden from view depending on the position of the resistor. So eventually, everyone switched to bands.

The colors are meant to follow the visible spectrum (remember ROY G BIV?). However, the RMA omitted indigo because apparently many people don’t distinguish blue, indigo, and violet as three different colors; indigo is really a tertiary color, anyway and Newton included it because of his interest in the occult, apparently. That leaves four slots, so dark colors represent the low end (black and brown) and bright colors the high end (gray and white).

Of course, none of this was funny if you were color blind. Reading a resistor with a meter or a bridge out of the circuit was certainly an answer. Reading one in a circuit, though, was another matter.

The Origin of E-Series Values

In 1952 the International Electrotechnical Commission (IEC, another standards group) defined the E-series which dictates what values resistors come in so that you get equal spacing on a log scale for resistors. If that sounds confusing, consider an example.

The E12 series is for 10% resistors and the values on it give you 12 values per decade. The base values are

1, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3., 3.9, 4.7, 5.6, 6.8, 8.2

That’s why you can get, say a 4.7 K or 47 K resistor but not a 40K resistor.

However, consider the tolerance. A 10% 39 K resistor could be off by 3.9 K. If the error pushed the resistance up that would be 42.9K, making a 40 K resistor unnecessary. That is, a 39 K resistor might well be a 40 K resistor, anyway. A low 47K resistor, on the other hand, could be 42.3 K, which is less than a high-value 39 K unit.

As you might expect, the number of values goes up as the tolerance goes down. At 2%, for example, you’ll use E48 which has 48 values per decade (if you’d guess E96 — the standard used for 1% has 96 values, you’d be right). Using E48, the values near 40 K are 38.3 K and 40.2 K. That’s 39.06 on the high side and 39.2 on the low side.

Next Time

Next time you pick up a resistor and read the code from it, you can recall the history behind it all. The legacy of color bands carries over into the surface mount realm, not as color but as three digits representing the first two numbers and multiplier for the resistor’s value. These days many electronics like wireless modules and lithium batteries include a datamatrix (something like a QR code) on them. Honestly, I’m surprised that all components — through hole and surface mount — don’t have some form of micro data matrix on it that lets you point your phone at them and see their complete datasheet. Maybe one day.


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Model S Motor and Volt Battery Go Together Like Peanut Butter and Jelly

A common project category on this site is “put a Raspberry Pi in it”. For people who wrench on their cars, a similarly popular project is the “LS Swap”. Over the past few years, the world of electronics and automotive hacking started to converge in the form of electric car conversions, and [Jalopnik] proclaims the electric counterpart to “LS Swap” is to put a Telsa Model S motor and a Chevy Volt battery into a project car.

The General Motors LS engine lineup is popular with petro heads for basically the same reasons Raspberry Pi are popular with the digital minded. They are both compact, very powerful for the money, have a large body of existing projects to learn from, and an equally large ecosystem of accessories to help turn ideas into reality. So if someone desired more power than is practical from a car’s original engine, the obvious next step is to swap it out for a LS.

Things may not be quite as obvious in the electric world, but that’s changing. Tesla Model S and Chevrolet Volt have been produced in volume long enough for components to show up at salvage yards. And while not up to the levels of LS swaps or Pi mods, there’s a decent sized body of knowledge for powerful garage-built electric cars thanks to pioneers like [Jim Belosic] and a budding industry catering to those who want to build their own. While the decision to use Tesla’s powerful motor is fairly obvious, the choice of Volt battery may be surprising. It’s a matter of using the right tool for the job: most of these projects are not concerned about long range offered by Tesla’s battery. A Volt battery pack costs less while still deliver enough peak power, and as it was originally developed to fit into an existing chassis, its smaller size also benefits garage tinkerers fitting it into project cars.

While Pi SBCs and LS engines are likely to dominate their respective fields for the foreseeable future, the quickly growing and evolving world of electric vehicles means this winning combo of today are likely to be replaced by some other combination in the future. But even though the parts may change, the spirit of hacking will not.

[Photo: by Jim Belosic of motor used in his Teslonda project]


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Additive, Multi-Voice Synth Preserves Sounds, Too

For his final project in [Bruce Land]’s infamous microcontroller design class, [Mark] set out to make a decently-sized synth that sounds good. We think you’ll agree that he succeeded in spades. Don’t let those tiny buttons fool you, because it doesn’t sound like a toy.

Why does it sound so good? One of the reasons is that the instrument samples are made using additive synthesis, which essentially stacks harmonic overtones on top the fundamental frequency of each note. This allows synthesizers to better mimic the timbre of natural, acoustic sounds. For each note [Mark] plays, you’re hearing a blend of four frequencies constructed from lookup tables. These frequencies are shaped by an envelope function that improves the sound even further.

Between the sound and the features, this is quite an impressive synth. It can play polyphonically in piano, organ, or plucked string mode through a range of octaves. A PIC32 runs the synthesizer itself, and a pair of helper PIC32s can be used to record songs to be played over. So [Mark] could record point and counterpoint separately and play them back together, or use the helper PICs to fine-tune his three-part harmony. We’ve got this thing plugged in and waiting for you after the break.

If PICs aren’t what you normally choose, here’s an FPGA synth.


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A DNA-Based Computer Calculates Square Roots Up To 900

While DNA-based computing may not be taking over silicon quite so soon, there is progress in the works. In a paper published by Small, researchers from the University of Rochester demonstrate a molecular computing system capable of calculating square roots of integers up to 900. The computer is built from synthetic biochemical logic gates using hybridization, a process where two strands of DNA join to form double-stranded DNA, and strand displacement reactions.

DNA-based circuits have already been shown to implement complex logic functions, but most existing circuits prior to the recent paper were unable to calculate square root operations. This required 4-bit binary numbers – the new prototype implements a 10-bit square root logic circuit, operating up to the decimal integer 900.

The computer uses 32 strands of DNA for storing and processing information. The process uses three modules, starting off with encoding a number on the DNA. Each combination is attached to a florescent marker, which changes signal during hybridization in the second module. The process for calculating the square root controls the signals, with the results deducted from the final color according to a threshold set in the third module.

We’re beginning to see the end of Moore’s Law approaching, with companies like Intel and AMD struggling to shrink transistors 10 nm wide. Nevertheless, with DNA molecules still about 10 time smaller than the best transistors today and DNA computing systems continuing to gain in sophistication, biochemical circuits could potentially be holding solutions to increasing the speed of computing beyond silicon computing.


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Take Security Up a Notch By Adding LEDs

All computers are vulnerable to attacks by viruses or black hats, but there are lots of steps that can be taken to reduce risk. At the extreme end of the spectrum is having an “air-gapped” computer that doesn’t connect to a network at all, but this isn’t a guarantee that it won’t get attacked. Even transferring files to the computer with a USB drive can be risky under certain circumstances, but thanks to some LED lights that [Robert Fisk] has on his drive, this attack vector can at least be monitored.

Using a USB drive with a single LED that illuminates during a read OR write operation is fairly common, but since it’s possible to transfer malware unknowingly via USB drives, one that has a separate LED specifically for writing operations will help alert a user to any write operations that might be trying to fly under the radar. A recent article by [Bruce Schneier] pointed out this flaw in USB drives, and [Robert] was up to the challenge. His build returns more control to the user by showing them when their drive is accessed and in what way, which can also be used to discover unique quirks of one’s chosen operating system.

[Robert] is pretty familiar with USB drives and their ups and downs as well. A few years ago he built a USB firewall that was able to decrease the likelihood of BadUSB-type attacks. Be careful going down the rabbit hole of device security, though, or you will start seeing potential attacks hidden almost everywhere.


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Hackaday Links: January 12, 2020

Nothing ruffles feathers more reliably than a software company announcing changes to its licensing terms. And so it goes with AutoDesk, who recently announced that Eagle would no longer be available as a standalone product and would now be bundled with Fusion 360. It looks like there’s still a free option for personal use, which is good even if it limits designs to two schematic sheets, two board layers, and 80 cm² board area. And perhaps this means there will be a Linux version of Fusion 360 too.

With the Y2K bug now twenty years in the rearview mirror, it’s entertaining to look back at that time and all the hype that surrounded it. Usually we talk about the effort that went into fixing vulnerable systems, but do we ever talk about the recipes of Y2K? The Advent of Computing podcast recently did an episode that gives a great background of the Y2K bug, plus discusses what people were planning to do for food after the bug detonated all the world’s nukes when the new millennium rolled around. Pantries stocked with canned goods, wood stoves to cook on and keep warm by when the powerplants all self-destructed on January 1 – it was all part of the vibe at the time.

We suppose when you put 60 birds into orbit at a time, it doesn’t take long to make a sizable impact on the planet’s constellation of satellites. Still, it came as a surprise that SpaceX was able to claim the title of world’s largest commercial satellite constellation after just three Starlink launches. We guess the operative term is “commercial” here, since some governments probably have far more satellites in service than the 182 Starlinks that have been launched so far. That’s a far cry from the 11,000 plus eventually predicted to form the Starlink constellation, but it’s already having an impact.

As a proud Idahoan, I feel personally triggered by what’s billed as the world’s first smart potato. True, I live in the part of the state with the trees and the bears, not the spuds, but still, it’s right there on our license plates. While clearly tongue-in-cheek, the Smart Potato pokes fun of our official State Vegetable, which I find beyond the pale. Seems like anything can be crowdfunded these days.

Speaking of which, check out Kohler’s Alex-connected smart toilet. For a mere $7,000 you can have a toilet that does everything a regular, boring old toilet does, but with lights. In fairness, the value of a good bidet can’t be overstated, but the ability to talk to your toilet and have it talk back seems a little on the iffy side. Perhaps teaming it up with the Charmin Poop-Bot, a self-balancing robot that connects to your phone and brings you a roll of toilet paper if you find yourself without a square to spare.

And finally, drummer Neil Peart died this week at the far-too-young age of 67. While there’s probably a fair number of Rush fans in the core hackaday demographic, there’s no hack or other tie-ins here. I’m just sad about it and wanted to share the news.


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DIY Ionizer Clears the Air on a Budget

Have you ever had a good, deep breath of the air near a waterfall, or perhaps after a thunderstorm? That unmistakably fresh smell is due to ionized air, specifically negative ions, and many are the claims concerning their health benefits. A minor industry has sprung up to capitalize on the interest in ionized air, and while [Amaldev] wanted to clean up the Mumbai air coming into his home, he didn’t want to pay a lot for a commercial unit. So he built his own air ionizer for only about $10.

When [Amaldev] dropped this in the Hackaday tip line, he indicated that he’d been taking some heat for the design from Instagram followers. We imagine a fair number of the complaints stem from the cluster of sewing needles that bristle from one end of the PCB and are raised to 6,000 volts by a fifteen-stage Cockcroft-Walton multiplier. That’s sure to raise eyebrows, or possible the hair on one’s head if you happen to brush by the emitters. Or perhaps [Amaldev]’s critics are dubious about the benefits of ionized air; indeed, some commenters on the video below seem to think that the smoke in the closed jar was not precipitated by the ion stream as [Amaldev] claims, but rather somehow was settled by heat or some other trickery.

Neither of those bothers us as much as the direct 230-volt mains connection, though. We’d have preferred to see at least an isolation transformer in there, or perhaps a battery-powered flyback circuit to supply the input to that multiplier. Still, the lesson on cascade multipliers was welcome, and we found the smoke-clearing power of ionized air pretty amazing.


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Awakening A Dragon From Its Slumber

For all the retrocomputing fun and games we encounter in our community, there are a few classic microcomputers that rarely receive any attention. Usually this is because they didn’t sell well and not many have survived, or were simply underwhelming machines that haven’t gathered a huge following today. One that arguably falls within both camps is the Dragon 32, a machine best known in those pre-Raspberry Pi days for being the only home computer manufactured in Wales, and for being nearly compatible with the Tandy Color Computer due to both machines’ designs coming from the same Motorola data sheet. Repeat restorer of retrocomputers, [Drygol], has given a Dragon 32 the full restoration and upgrade treatment, offering us a rare chance to take a look at this computer.

The Dragon arrived with a pile of contemporary books and software, but no power supply. A significant modification was made to the internal PSU board then to allow it to work with an Amiga unit, and the black-on-green Dragon text came up on the TV screen. Recapping and a replacement for a faulty op-amp fixed poor video quality, then it was time for a 64K memory upgrade with some neatly done bodge-wiring. Finally there’s a repair to the very period-looking analogue joystick, and a home-made interface for the more common Atari/Amiga style sticks.

The Dragon may be only a footnote in the history of 8-bit home computing, but with its good expandability and decent quality keyboard it perhaps deserved to reach more homes than it did. This appears to be the first time a Dragon has featured here, though its Tandy CoCo cousin has made it into a few stories.


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Maze Solving Via Text Editing

Linux scripters usually know about sed — the stream editor. It has a simple job: transform text as it whizzes from input to output. So if you wanted to solve a maze, this wouldn’t be the tool you’d think to use, right? Well, if you were [xsot], you’d disagree.

You build a maze using spaces for empty space and # for walls. There’s an S to mark the start position and an E to mark the end. Of course, the maze can also contain newlines. The sed script does an amazing job of solving the problem.

As the author points out:

The main difficulty lies in the lack of the luxuries usually provided in a regular programming language such as:

  • arithmetic
  • data types other than strings
  • more than 2 “variables”

Also, sed regex lacks features present in other regex systems such as PCRE (non-greedy matching, lookaheads, etc).

We will confess, we didn’t pull the whole 122 line script apart to understand it, but it looks like it replaces spaces with special marker characters that relate to the direction from the end to the start. The characters U, D, L, and R indicate the direction. Then it is able to select the closest character and replaces them with arrows (well, a letter v, a caret, and the less than and greater than signs).

A very unusual hack of using sed, we think. The output is even colorized and animated. Amazing.

We can’t say we’ve ever done anything this bizarre with a scripting command. We have looked at scripting many times, though, if you want to brush up. Probably the closest we’ve come is using bash scripts to process binary files.


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Generating Beetles from Public Domain Images

Ever since [Ian Goodfellow] and his colleagues invented the generative adversarial network (GAN) in 2014, hundreds of projects, from style transfers to poetry generators, have been produced using the concept of contesting neural networks. Unlike traditional neural networks, GANs can generate new data that fits statistically within the same set as the training set.

[Bernat Cuni], the one-man design team behind [cunicode] came up with the idea to generate beetles using this technique. Inspired by material published on Machine Learning for Artists, he decided to deploy some visual experiments with zoological illustrations. The training data was found from a public domain book hosted at, found through the Biodiversity Heritage Library. A combination of OpenCV and ImageMagick helped with individually extracting illustrations to squared images.

Generating Beetles from Public Domain Images

[Cuni] then ran a DCGAN with the data set, generating the first set of quasi-beetles after some tinkering with epochs and settings. After the failed first experiment, he went with StyleGAN, setting up a machine at PaperSpace with 1 GPU and running the training for >3 days on 128 px images. The results were much better, but fairly small and the cost of running the machine was quite expensive (>€125).Generating Beetles from Public Domain Images

Given the success of the previous experiment, he decided to transfer over to Google CoLab, using their 12 hours of K80 GPU per run for free to generate some more beetles. With the intent on producing more HD beetles, he used Runway trained on 1024 px beetles, discovering much better results after 3000 steps. The model was moved over to Google CoLab to produce HD outputs.

He has since continued to experiment with the beetles, producing some confusing generated images and fun collectibles.

Check out the beetles here:


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A Supercapacitor Might Just Light Your Way One Day

Sometimes the simplest hacks are the most useful ones, and they don’t come much simpler than the little supercapacitor LED flashlight from serial maker of cool stuff [Jeremy S. Cook]. Little more than an LED, a supercapacitor, USB plug, and couple of resistors, it makes a neat little flashlight that charges from any USB A power socket and delivers usable light for over half an hour.

It’s neat, but on its own there’s not much to detain the reader until it is revealed as a “Hello World” supercapacitor project from an article in which he delves into the possibilities of these still rather exotic components. Its point is to explore their different properties when compared to a battery, for example a linear voltage drop in contrast to the sharp drop-off of a chemical cell. In the video below the break we see him try a little boost regulator to deliver a constant voltage, with consequent severe loss of lighting time for the LED. It’s by this type of experimentation that we learn our way around a component unfamiliar to us, and the article and video are certainly worth a look if you’ve never used a supercapacitor before.


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NanoVNA Tests Antenna Pattern

When [Jephthai] wanted to build his own Yagi antenna, he turned to MMANA software for antenna modeling. This is an antenna analysis program that uses the moment method to calculate parameters for different antenna geometries. After building the Yagi, the predicted tuning and impedance matched the real antenna nicely. But what about the radiation pattern? To test that, he used a NanoVNA and a clever test setup.

He needed a test spot out of the antenna’s near field so he set up his workstation 18 feet away from the test antenna which was on a mount that could rotate. On the edge of the workstation table — affixed with painter’s tape — is a NanoVNA connected to a laptop.

The rest is just sweat work. First, make a measurement on the resonant frequency. Then rotate the antenna 10 degrees and repeat. After 36 measurements you have the entire circle.

Plotting the resulting data with GNUPlot matched up pretty well with the antenna’s predicted performance. This was actually the second attempt and in the report, [Jephthai] reports that keeping alignment is critical to get everything to work. You can see in his pictures some of the steps he took to maintain consistency.

Another aid to consistency was the use of the NanoVNASaver software. This software allows for a frequency sweep along with a display and the creation of Touchstone files.

We’ve looked at the NanoVNA before. If you’d rather view your antenna pattern as a 3D volume, break out the 3D printer.


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This Artist Drags His Feet Across Sand and Snow

You may have seen Simon Beck’s work a few years back. The snow artist, known for creating large-scale works of art with nothing but snowshoes, has been creating geometrically inspired fractals and mathematical forms for years. An orienteer and map-maker by day, he typically plans out his works in advance and chooses sites based on their flat terrain. The lack of slopes prevents skiers from traversing the area beforehand and helps with measuring the lines needed to create the drawing.

He starts off by measuring the distance he has to be from the center by using a compass and walking in a straight line towards a point in the distance, making curves based on relative position to other lines. Once the primary lines are made, he measures points along the way using pace counting and joins secondary lines by connecting the points. The lines are generally walked three times to solidify them before filling in the shaded areas. The results are mesmerizing.

He has since expanded to sand art, using the same techniques that gained him fame in ski resorts and national parks on the sandy shores. Unfortunately, tidal patterns, seaweed, and beach debris make it slightly harder to achieve pristine conditions, but he has managed to create some impressive works of art nonetheless.



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Plucky Kalimba Plays Itself

[Gurpreet] fell in love with the peaceful, floaty theme from the Avatar series and bought a kalimba so he could hear it resonate through his fingertips. He soon realized that although it’s nice to play the kalimba, it would be a lot cooler if it played itself. Then he could relax and enjoy the music without wearing out his thumbs.

After doing a bit of experimentation with printing tine-plucking extensions for the servo horns, [Gurpreet] decided to start the design process by mounting the servos on a printed base. The servos are slotted into place by their mounting tabs and secured with hot glue. We think this was a good choice — it’s functional and it looks cool, like a heat sink.

[Gurpreet]’s future plans include more servos to pluck the rest of the tines, and figuring out how feed it MIDI and play it real time. For the demo after the break, [Gurpreet] says he lapel mic’d the kalimba from the back and cut out the servo noise with Audacity, but ultimately wants to figure out how to quiet them directly. He’s going to try lubing the gears and making a sound-dampening enclosure with foam, but if you have any other ideas, let him know down below.

We don’t see too many kalimba projects around here, but here’s one connected to a Teensy-based looper.

Via [r/arduino]


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Printed Separator Separates Printed Pages

We all know people trapped in aging bodies who can’t do all the things they used to do. It’s easy to accept that you may never move small furniture around by yourself again, but losing the ability to do something as simple as separating the pages of your newspaper to keep reading it is an end to enjoyment.

When [Randomcitizen4] visited his grandma over the holidays, she mentioned having trouble with this, among other things. He fired up his printer and got to work designing a device to help her get back to the funny pages. This simple gripper mechanism uses rubber bands for tension and flexible filament to get a firm grip on the paper. The jaws default to the open position so they’re ready to grab some newsprint, and a light squeeze of the handles slides the top page back from the stack, creating a gap for Grandma’s fingers. You can see a demo on page 32 after the break.

Although the device does work on some books and magazines, he’d like to improve the design of the grips to make the device more universally useful. [Randomcitizen4] says he tried a few things already, but we wonder if a more complex surface pattern might do the trick — maybe less like fins and more like a tire tread pattern. All the STLs are available if you want to give it a go.

If Grandma’s newspaper ever goes out of print, she should still be able to read it on a tablet or an e-reader. Then maybe [Randomcitizen4] can build some kind of remote-controlled page turner for her.