For something that has been around since the 1930s and is so foundational to computer science, you’d think that the Turing machine, an abstraction for mechanical computation, would be easily understood. Making the abstract concepts easy to understand is what this Turning machine demonstrator aims to do.

The TMD-1 is a project that’s something of a departure from [Michael Gardi]’s usual fare, which has mostly been carefully crafted recreations of artifacts from the early days of computer history, like the Minivac 601  trainer and the DEC H-500 computer lab. The TMD-1 is, rather, a device that makes the principles of a Turing machine more concrete. To represent the concept of the “tape”, [Mike] used eight servo-controlled flip tiles. The “head” of the machine conceptually moves along the tape, its current position indicated by a lighted arrow while reading the status of the cell above it by polling the position of the servo.

Below the tape and head panel is the finite state machine through which the TMD-1 is programmed. [Mike] limited the machine to three states and four transitions, each of which is programmed by placing 3D-printed tiles on a matrix. Magnets were inserted into cavities during printing; Hall Effect sensors in the PCB below the matrix read the pattern of magnets to determine which tiles are where. The video below shows the TMD-1 counting from 0 to 10, which is enough to demonstrate the basics of Turing machines.

It’s hard not to comment on the irony of a Turing machine being run by an Arduino, but given that [Mike]’s goal was to make abstract concepts easy to understand, it makes perfect sense to leverage the platform rather than try to do this with discrete logic. And you can’t argue with results — TMD-1 made Turing machines clear to us for the first time.

source https://hackaday.com/2020/08/27/tmd-1-makes-turing-machine-concepts-easy-to-understand/

Pity the poor TTL computer aficionado. It’s an obsession, really — using discrete logic chips to scratch-build a computer that would probably compare unfavorably to an 80s era 8-bit machine in terms of performance. And yet they still forge ahead with their breadboards full of chips and tangles of wire. It’s really quite beautiful when you think about it.

[Duncan] at Shepherding Electrons has caught the TTL bug, and while building his 8-bit machine outfitted it with this discrete logic UART. The universal asynchronous receiver-transmitter is such a useful thing that single-chip versions of the device have been available since the early 1970s. [Duncan]’s version makes the magic of serial communications happen in just 12 chips, all from the 74LS logic family.

As if the feat of building a discrete logic UART weren’t enough, [Duncan] pulled this off without the aid of an oscilloscope. Debugging was a matter of substituting the 2.4576-MHz crystal oscillator clock with a simple 1-Hz 555 timer circuit; the reduced clock speed made it easier to check voltages and monitor the status of lines with LEDs. Once the circuit was working, the full-speed clock was substituted back in, allowing him to talk to his 8-bit computer at up to 38,400-kbps. Color us impressed.

For more TTL computer goodness, and to see where [Duncan] got his inspiration, check out [Ben Eater]’s many discrete logic projects — his scratch-built 6502, a low-end video card, or even his take on serial communications.

source https://hackaday.com/2020/08/26/discrete-logic-uart-keeps-8-bit-ttl-computer-connected/

Batteries have come a long way in the past few centuries, but pale in comparison to hydrocarbon fuels when it comes to energy density. When it comes to packing plenty of juice in a light, compact package, hydrocarbons are the way to go. Recently, researchers have begun to take advantage of this, powering small robots with liquid fuels. Just like Bending Unit 22, aka Bender Bending Rodriguez, this tiny robotic beetle runs on alcohol.

Affectionately named Robeetle, the tiny ‘bot weighs just 88 milligrams, comparable in mass its insectoid contemporaries. It stores methanol in a polyimide film tank, operating for up to 2 hours on a single fill.  As shown in the video, a solely mechanical control system is used to actuate the robot’s legs. In the neutral state, vents in the fuel tank are open, releasing methanol vapor. This passes over nitinol muscle wires coated in a special catalyst which causes the combustion of the methanol, heating the wires. The wires then contract, moving the legs, and closing the vents. When the wire cools, the wires relax, opening the vents and beginning the cycle anew.

While the ‘bot is solely capable of walking in a single direction, it nevertheless shows the possibilities enabled by powering small devices from energy-dense fuels. Waiting for improved battery technologies to develop is such a bore, after all. We look forward to swarms of such ‘bots exploring disaster areas or performing environmental sampling in years to come. The scientific paper outlines the research outcomes in detail.

We love tiny robots at Hackaday; we’ve featured a few in the past, too. Video after the break.

source https://hackaday.com/2020/08/26/tiny-robot-beetle-runs-on-alcohol/

Batteries have come a long way in the past few centuries, but pale in comparison to hydrocarbon fuels when it comes to energy density. When it comes to packing plenty of juice in a light, compact package, hydrocarbons are the way to go. Recently, researchers have begun to take advantage of this, powering small robots with liquid fuels. Just like Bending Unit 22, aka Bender Bending Rodriguez, this tiny robotic beetle runs on alcohol.

Affectionately named Robeetle, the tiny ‘bot weighs just 88 milligrams, comparable in mass its insectoid contemporaries. It stores methanol in a polyimide film tank, operating for up to 2 hours on a single fill.  As shown in the video, a solely mechanical control system is used to actuate the robot’s legs. In the neutral state, vents in the fuel tank are open, releasing methanol vapor. This passes over nitinol muscle wires coated in a special catalyst which causes the combustion of the methanol, heating the wires. The wires then contract, moving the legs, and closing the vents. When the wire cools, the wires relax, opening the vents and beginning the cycle anew.

While the ‘bot is solely capable of walking in a single direction, it nevertheless shows the possibilities enabled by powering small devices from energy-dense fuels. Waiting for improved battery technologies to develop is such a bore, after all. We look forward to swarms of such ‘bots exploring disaster areas or performing environmental sampling in years to come. The scientific paper outlines the research outcomes in detail.

We love tiny robots at Hackaday; we’ve featured a few in the past, too. Video after the break.

source https://hackaday.com/2020/08/26/tiny-robot-beetle-runs-on-alcohol/

Batteries have come a long way in the past few centuries, but pale in comparison to hydrocarbon fuels when it comes to energy density. When it comes to packing plenty of juice in a light, compact package, hydrocarbons are the way to go. Recently, researchers have begun to take advantage of this, powering small robots with liquid fuels. Just like Bending Unit 22, aka Bender Bending Rodriguez, this tiny robotic beetle runs on alcohol.

Affectionately named Robeetle, the tiny ‘bot weighs just 88 milligrams, comparable in mass its insectoid contemporaries. It stores methanol in a polyimide film tank, operating for up to 2 hours on a single fill.  As shown in the video, a solely mechanical control system is used to actuate the robot’s legs. In the neutral state, vents in the fuel tank are open, releasing methanol vapor. This passes over nitinol muscle wires coated in a special catalyst which causes the combustion of the methanol, heating the wires. The wires then contract, moving the legs, and closing the vents. When the wire cools, the wires relax, opening the vents and beginning the cycle anew.

While the ‘bot is solely capable of walking in a single direction, it nevertheless shows the possibilities enabled by powering small devices from energy-dense fuels. Waiting for improved battery technologies to develop is such a bore, after all. We look forward to swarms of such ‘bots exploring disaster areas or performing environmental sampling in years to come. The scientific paper outlines the research outcomes in detail.

We love tiny robots at Hackaday; we’ve featured a few in the past, too. Video after the break.

source https://hackaday.com/2020/08/26/tiny-robot-beetle-runs-on-alcohol/

With all the focus on biological problems, we might forget that sometimes it’s handy to know about radiation hazards, too. [Ryan Harrington] shows us how to make a Geiger counter with very few parts, and you can see the results in the video below.

The glut of surplus Russian tubes has made this a common project, but we were amused to see the main part of the high-voltage supply was gutted from a cheap electronic flyswatter sourced from Harbor Freight. Even without a coupon, it only costs about $4.

There’s also a stack of zener diodes, a transistor, and some resistors. A battery, a piezo speaker, and a switch round out the bill of materials. Even then, the switch was upcycled from the flyswatter, so there’s not much to buy.

We see these flyswatters on deep sale sometimes, so maybe next time we do we’ll stock up. You could probably use the high voltage module for other projects, too. The module puts out enough voltage that it needs 400V worth of zener diodes to clamp it. [Ryan] used four 100V zeners.

The transistor causes the speaker to click. Apparently you can omit it, but the clicking becomes much harder to hear. Even with no radioactive material around, you’ll hear clicks occasionally from background radiation. But if you get the device near a smoke detector or a lantern mantle, you should hear a lot more clicks.

This reminded us of another cheap build with a camera flash. Want something more complex? Try this one.

source https://hackaday.com/2020/08/26/this-geiger-counter-has-few-parts/

Those of you who were regular office dwellers before the pandemic: do you miss being with your coworkers at all? Maybe just a couple of them? There’s only so much fun you can have through a chat window or a videoconference. Even if you all happen to be musicians with instruments at the ready, your jam will likely be soured by latency issues.

[Eden Bar-Tov] and some fellow students had a better idea for breaking up the work-from-home monotony — a collaborative sequencer built for 2020 and beyond. Instead of everyone mashing buttons at once and hoping for the best, the group takes turns building up a melody. Each person is assigned a random instrument at the beginning, and the first to go is responsible for laying down the beat.

Inside each music box is an ESP8266 that communicates with a NodeRed server over MQTT, sending each melody as a string of digits. Before each person’s turn begins, the LED matrix shows a three second countdown, and then scrolls the current state of the song. Your turn is over when the LED strip around the edge goes crazy.

Music can be frustrating if you don’t know what you’re doing, but this instrument is built with the non-musician in mind. There are only five possible notes to play, and they’re always from the same scale to avoid dissonance. Loops are always in 4/4, which makes things easy. Players don’t even have to worry about staying in time, because their contributions are automatically matched to the beat. Check it out after the break.

Tired of sitting indoors all day, but still want to make music? Build a modular synth into a bike and you’ve solved two problems.

source https://hackaday.com/2020/08/26/slack-off-from-home-with-a-networked-jam-session/

While most analog televisions come with composite video inputs on a yellow RCA jack, the feature is not universal. This problem was even more prevalent in the 1980s, and most home consoles got around the problem by instead feeding video to the television’s tuner with an RF modulator. [Manzel Seet] had just such a television which used the PAL standard. Wanting to display images from a microcontroller, he put together PAL-Streamer.

The aim of the project was to display images on an analog television with minimal investment in hardware over and above what [Manzel] already had on hand. To this end, the project was built using a STM32F411 Nucleo development board. Capable of running at clock speeds up to 100 MHz, there’s plenty of grunt to handle demanding tasks like outputting video signals to a TV.

To achieve the target frequency of VHF Channel 3 (61.25 MHz), [Manzel] elected to rely on the onboard PWM hardware, after being inspired by [CNLohr]’s ATTiny NTSC project. The project takes advantage of the odd harmonics of square waves. Setting the PWM output to operate at 6.86 MHz, the ninth harmonic ends up at around 61.71 MHz, close enough to be tuned in on the TV set. With the hard part done, [Manzel] then implemented a virtual COM port allowing an attached PC to send PNG images or GIF animations to the display.

It’s a fun project that shows it’s possible to drive all kinds of analog displays if you’re willing to be creative about how you do it. Files are available on GitHub for those eager to recreate the work. [Manzel] points out that this method does put out a lot of RF energy in the surrounding bands, but for direct hookup to an antenna input, it works just fine. We love to see creative video projects on microcontrollers, so if you’ve figured out how to get an Arduino Uno to do 1080P over HDMI, be sure to let us know. Video after the break.

source https://hackaday.com/2020/08/26/driving-a-pal-tv-over-rf-thanks-to-pwm-harmonics/

This post is different from normal Hackaday fare. I don’t want to presume anything about you, but I’m pretty sure the story I’m about to share resonates with at least some of you.

I’ve been having a tough time, exacerbated by this age of social distancing. This all crept up on me at first, but as I began to look back on my behavior and moods, I began noticing patterns that I hadn’t noticed before. This is certainly a relevant issue in this community, so let’s talk about mental health, beginning with my own journey.

Discovering the Problem

I am a prolific maker. I always have projects that I’m working on, projects that I’m thinking about working on, and projects that I’m getting paid to work on. I have an idea about how long the projects should take, and I get stressed and frustrated and beat myself up when they take longer than I think they should. I can’t admit defeat, so I continue the project until it is complete, but all of the joy is gone because it was stressful more than fun while I was working on it. Even at completion it’s difficult to enjoy the product because I’m already behind on starting the next thing in my queue (you may remember my earlier article on dealing with time debt). Further, I haven’t documented the project enough for my own satisfaction, so I’m uncomfortable sharing it to the public. It’s a perpetual problem, leading to perpetual grump.

I see other people on Hackaday and YouTube who are also prolific makers, but they have millions of subscribers, do much cooler projects, and put them out at a frequency I could only dream of. Imposter syndrome creeps in. I work harder on my projects, spending more and more time on them; the family makes fun of the fact that I’m the “basement troll” whose primary line is “I have to work on my projects.” Weekends are spent primarily watching YouTube and scrolling Reddit (but not contributing) and beating myself up for not working harder and getting on top of my pile of things to fix or improve around the house.

I have no social life to speak of. I had a plan, but the pandemic trashed that, and I still haven’t discovered a solution. People assume that I’m super busy and don’t have time to socialize, but the reality is that working on projects is a default for me, but not a preference, and it’s a thing I can do alone, so it’s easy to fall into.

The inner voice is loud, constant, and extremely critical. It tells me my work isn’t good enough, I’m not fast enough, I’m not interesting enough to have friends. Just to put something out there is a huge risk, and anyone who reads Hackaday regularly knows that the commenters are really good at identifying the slightest mistakes, meaning I agonize about every sentence far longer than I should.

This has been getting worse for years, though I didn’t notice and it wasn’t until someone pointed it out that I even realized it. It’s a self-perpetuating cycle that’s difficult to discover, and really difficult to get out of, especially with the inner voice. This is more than just being too busy, depression and anxiety have crept into the picture for me and these are not issues that should be ignored. So I got some help and started working through the problem.

Dealing with the problem

The hardest part about depression and anxiety is getting started. The voice is telling you you can’t, and that even if you could, life sucks and there’s nothing to look forward to. Enter one of the most important scenes in movie history.

The movie magic of The Matrix reduces the difficult part for learning incredible skills to an eye flutter, but the point is not to say “I can’t” and give up; it’s to say “not YET”, and then learn the skills you need to do the thing.

One of the most important steps in getting out of the rut for me has been to silence the critic. With the bully crushing me constantly, I didn’t have a chance of getting out. Therapy was helping, but it wasn’t enough. What helped a lot was prescribed antidepressants. Antidepressants are not an easy thing to take. Most people have to try a few different medications before finding one that works, and then adjust the dose to get it right. The side effects are no joke, either, and sometimes make things worse than they were before. And they can take weeks to start to become effective. It’s tempting to give up on them, or endure the side effects of a misfit longer than you should.

In my case I started one at the direction of my doctor, had headaches and migraines and extreme exhaustion for a little more than a week, and stopped, waited two weeks to return to a baseline, then started a new medication. After a couple weeks of that, with few side effects but not much positive benefit, we increased the dose a little. A week later the inner critic was gone, I was no longer irrationally irritable, and while the exhaustion hasn’t gone away, it was eased somewhat by switching to nighttime for taking the med. I still have off days where I feel like I did before the meds, but they are rare and recognizable.

I also reached out on social media to friends and family, and explained what I was going through, and that I needed more social interaction. This was a huge success, and I spent weeks catching up with people I hadn’t talked to in decades. One of the biggest lessons here was that it’s ok to absolve yourself of the guilt of not keeping in constant contact with people, and that it’s ok to say “we haven’t talked in a long time. What’s your life like?”

Solving the Problem

For many, pharmaceuticals are the solution. They are content to silence the inner voice so they can resume their day-to-day. I hope that for me they will just be a crutch on my way to healing; a temporary measure that will allow me to change the underlying cause of the injury to my mental health. Maybe my brain is broken and not capable of producing the right chemicals, and antidepressants will be a permanent solution. I hope not, and here are the more permanent mental fitness goals that research has shown are likely to be successful.

• Therapy – It’s important to find a good therapist whose methods agree with your goals. My first attempt wanted to meet more frequently than I was comfortable and talk about my broken home as a child, and ignored my pleas to deal with my current problems and find tools to get through until I had resolved my childhood. My current therapist is far better, and listens and suggests tools that make sense. Consider something called Cognitive Behavioral Therapy.
• Exercise – The statistics are solid here. Most of us aren’t getting enough exercise now anyway, which just makes the problem worse. One of the reasons I develop hardware and not just software is I like to do things with my hands and see physical progress and point to something I built. That’s hard when working on mental health, but if you also work on your physical health, you’ll have demonstrable results you can point to.
• Gratitude journaling – This one also has lots of science behind it. The idea is to regularly write down things for which you are grateful. Short lists are fine. The point is to get in the habit of thinking about good things in your life. It’s really difficult to start, and for a while I was criticizing myself because most of my entries were spins on things that I didn’t like “I like that I have the skills to fix the house when it breaks.” Then I realized that was actually exactly the point of the exercise; that instead of focusing on all the terrible things like the house falling apart all the time, I should be appreciating and celebrating the good things more, like the satisfaction of looking around the room at all the things I’ve done to improve it. Eventually this becomes a habit and the gratitude journal becomes ingrained in the brain.
• Social interaction – This is hard, but extremely important right now. When nobody reached out to me for months I was miserable, but I realized I wasn’t reaching out to anybody, either. After an experiment I discovered that the things I feared about reaching out pretty much never happen. It feels good to interact with people and have friends. You feel more important and seen.
• Giving – There are a lot of people struggling right now. Not more than you; this isn’t a contest. But struggling in ways that you can offer help. Find causes that you believe in, and offer to help in whatever ways you can contribute. Feeling needed is important, feeling like you are valued and that you’ve made someone’s life better is a good thing.
• Putting more out there – I recently presented a project at my local makerspace’s monthly meeting (now held over zoom). It wasn’t a finished project, but I did it anyway. There were so many details in the work I had done that deserved attention that it didn’t matter that it wasn’t yet complete. You’re not going to be just like Colin Furze and Mark Rober and Adam Savage and all the others combined; that’s not your day job (unless you are Colin or Mark or Adam, in which case I’m honored that you are reading this, and please don’t have imposter syndrome comparing yourself to yourself). But you can put out something and some people will see it and they will be more supportive than nobody.
• Fake it until you make it – Your inner critic is a lying jerk, and you know it’s a lying jerk, but you can’t ignore it. Well, you can pretend you are ignoring it. This was the actual advice of my therapist. He’s pretty cool. Objectively, you know the science is behind doing the things you want to do but just can’t. You know the science says you should exercise and eat right and be more social, and yet your inner critic tells you that you can’t. If you can ignore that critic just long enough to get started (and many people require antidepressants to help them get started with this), then you can discover that your inner critic was wrong all along and it becomes easier to ignore it.
• Listen to your inner critic, then do what they say – I had this revelation on my own, and it was completely counter to the previous point, but it was oddly successful. One day I was beating myself up a lot, and I decided to just give in to my inner critic. I wasn’t giving enough; so I researched a few charities and donated. I wasn’t exercising enough; so I went for a run. I wasn’t doing enough social things; so I reached out to three friends. Every time my voice criticized me I acknowledged it, agreed with it, and did something about it. It worked really well, and felt empowering because I was dealing with everything my critic was throwing at me. Maybe I didn’t give enough or exercise enough, but I did what I could do at the time, and the voice couldn’t make me feel guilty about that more than I felt good about doing something.

Conclusions

While an article can have a hasty conclusion, depression and anxiety usually don’t. This is likely something many of us are dealing with, now more than ever, and it’s likely to stick around for a while. It affects a lot of people, and you don’t often know who, so please be gentle to others, including yourself. I’ll end with a video I recently discovered, which illustrates that the problems persist at all levels, and we probably all have some work to do.

source https://hackaday.com/2020/08/26/dealing-with-a-hacked-brain-lets-talk-about-depression/

Working with graphics on microcontrollers has always meant focusing on making the most of limited resources. Particularly in the 8-bit era, all manner of tricks were used to get low-performance chips to achieve feats beyond their lowly station. However, these days, we’re blessed with 32-bit workhorses with clock speeds in the tens, or even hundreds, of MHz and many kilobytes of RAM to match. It’s these higher performance chips [Larry] had in mind when writing his JPEGDEC library.

As [Larry] discusses in a blog post on the topic, JPEG libraries already exist for the Arduino platform. However, many of these are aimed at 8-bit platforms with tiny amounts of RAM. While it’s possible to decode JPEGs piece by piece with some intelligent code under these conditions, it’s possible to go much faster when you’ve got a little more headroom. [Larry] does a great job of explaining the variety of optimizations he’s developed in the two decades since writing his first JPEG decoder back in 1994. From eliminating unnecessary marker checks to ignoring unneeded data for scaled-down output, it all adds up to get the job done faster. The library targets the Cortex-M0+, or any chip with a minimum of 20K of RAM, as its bare minimum to operate. Faster chips with higher clock rates naturally do better, and [Larry] provides benchmark decoding times for various common hardware using the library.

We’ve featured [Larry]’s GIF decoder for the Arduino platform before, again a useful library that’s optimised for good performance. If you’ve got your own neat tricks for image processing on microcontrollers, you know how to call!

source https://hackaday.com/2020/08/26/new-arduino-jpeg-library-focuses-on-speed/

In the 60s a musical recording technique called the “wall of sound” came to prominence which allowed artists to create complex layers of music resulting in a novel, rich orchestral feeling. While this technique resulted in some landmark albums (Pet Sounds by the Beach Boys for example) it took entire recording studios and many musicians to produce. This guitar, on the other hand, needs only a single musician but can create impressive walls of sound on its own thanks to some clever engineering.

Called the Circle Guitar and created by [Anthony Dickens], the novel instrument features a constantly-rotating wheel around the guitar’s pickups in the body. Various picks can be attached in different ways to the wheel which pluck the strings from behind continuously. This exceeds what a normal guitar player would be able to do on their own, but the guitarist is able to control the sounds by using several switches and pushbuttons which control a hexaphonic humbucker and are able to mute individual strings at will. Of course, this being the 21st century, it also makes extensive use of MIDI and [Anthony] even mentions the use of a Teensy.

While details on this project are admittedly a little fleeting, the videos linked below are well worth a watch for the interesting sounds this guitar is able to produce. Perhaps paired with a classic-sounding guitar amplifier it could produce other impressive walls of sound as well. Either way, we could expect someone like [Brian Wilson] to be interested in one once it is in production.

Thanks to [Mel] for the tip!

 

source https://hackaday.com/2020/08/26/circle-guitar-creates-wall-of-sound/

Sunrises and sunsets hardly ever disappoint. Still, it’s difficult to justify waking up early enough to catch one, or to stop what you’re doing in the evening just to watch the dying light. If there’s one good thing about CCTV cameras, it’s that some of them are positioned to catch a lovely view of one of the two, and a great many of them aren’t locked down at all.

[Dries Depoorter] found a way to use some of the many unsecured CCTV cameras around the world for a beautiful reason: to constantly show the sun rising and setting. Here’s how it works: a pair of Raspberry Pi 3B + boards pull the video feeds and display the sunrise/sunset location and the local time on VFD displays using an Arduino Nano Every. There isn’t a whole lot of detail here, but you can probably get the gist from the high-quality pictures.

If you wanted to recreate this for yourself, we might know where you can find some nice CCTV camera candidates. Just look through this dystopian peephole.

Thanks for the tip, [Luke]!

source https://hackaday.com/2020/08/25/sunrise-sunset-repeat/

We all probably know that for ultimate control and maximum performance, you need assembly language. No matter how good your compiler is, you’ll almost always be able to do better by using your human smarts to map your problem onto a computer’s architecture. Programming in assembly for PCs though is a little tricky. A lot of information about PC assembly language dates back from when assembly was more common, but it also covers old modes that, while still available, aren’t the best answer for the latest processors. [Gpfault] has launched a series on 64-bit x86 assembly that tries to remedy that, especially if you are working under Windows.

So far there are three entries. The first covers setting up your toolchain and creating a simple program that does almost nothing. But it is a start.

The second entry talks more about FASM and how to use macros and other features to simplify your programming. In particular, he shows macros that can wrap details like PE tables and calling convention protocols to make things easier. You wind up with a working Hello World program.

The third entry starts work on a fantasy CPU emulator, QBX. This isn’t a bad idea since emulating a CPU forces you to use many of the host computer instructions and doesn’t require any special knowledge other than what you probably have if you are trying to learn assembly language, anyway.

Of course, if you are writing boot code, you need to know all that old-fashioned legacy stuff. We liked [Ben Jojo’s] tutorial for that. If Linux is more your jam, we have an introduction for that, too.

Header: AMD Ryzen x86-64 processor, Fritzchens Fritz / CC0

source https://hackaday.com/2020/08/25/assembly-language-for-real/

The Bosch BME680 is a super-capable environmental sensor, and [Random Nerd Tutorials] has married it to the ESP32 to create an air quality meter that serves as a great tutorial on not just getting the sensor up and running, but also in setting up a simple (and optional) web server to deliver the readings. It’s a great project that steps through everything from beginning to end, including how to install the necessary libraries and how to program the ESP32, so it’s the perfect weekend project for anyone who wants to learn.

The BME680 is a small part that communicates over SPI or I2C and combines gas, pressure, temperature, and humidity sensors. The gas sensor part detects a wide range of volatile organic compounds (VOCs) and contaminants, including carbon monoxide, which makes it a useful indoor air quality sensor. It provides only a relative measurement (lower resistance corresponds to lower air quality) so for best results it should be calibrated against a known source.

The tutorial uses the Arduino IDE with an add-on to support the ESP32, and libraries from Adafruit. Unfamiliar with such things? The tutorial walks through the installation of both. There’s a good explanation of the source code, and guidance on entering setup values (such as local air pressure, a function of sea level) for best results.

Once the software is on the ESP32, the results can be read from the serial port monitor. By going one step further, the ESP32 can run a small web server (using ESPAsyncWebServer) to serve the data to any device wirelessly. It’s a well-written tutorial that covers every element well, and complements this other BME680-based air quality meter that uses MQTT and Raspberry Pi.

source https://hackaday.com/2020/08/25/two-part-four-wire-air-quality-meter-shows-how-its-done/

The Bosch BME680 is a super-capable environmental sensor, and [Random Nerd Tutorials] has married it to the ESP32 to create an air quality meter that serves as a great tutorial on not just getting the sensor up and running, but also in setting up a simple (and optional) web server to deliver the readings. It’s a great project that steps through everything from beginning to end, including how to install the necessary libraries and how to program the ESP32, so it’s the perfect weekend project for anyone who wants to learn.

The BME680 is a small part that communicates over SPI or I2C and combines gas, pressure, temperature, and humidity sensors. The gas sensor part detects a wide range of volatile organic compounds (VOCs) and contaminants, including carbon monoxide, which makes it a useful indoor air quality sensor. It provides only a relative measurement (lower resistance corresponds to lower air quality) so for best results it should be calibrated against a known source.

The tutorial uses the Arduino IDE with an add-on to support the ESP32, and libraries from Adafruit. Unfamiliar with such things? The tutorial walks through the installation of both. There’s a good explanation of the source code, and guidance on entering setup values (such as local air pressure, a function of sea level) for best results.

Once the software is on the ESP32, the results can be read from the serial port monitor. By going one step further, the ESP32 can run a small web server (using ESPAsyncWebServer) to serve the data to any device wirelessly. It’s a well-written tutorial that covers every element well, and complements this other BME680-based air quality meter that uses MQTT and Raspberry Pi.

source https://hackaday.com/2020/08/25/two-part-four-wire-air-quality-meter-shows-how-its-done/

Here at Hackaday, we pride ourselves on bringing you the freshest of hacks, preferably as soon as we find out about them. Thanks to the sheer volume of cool hacks out there, though, we do miss one occasionally, like this e-waste horizontal CNC mill that we just found out about.

Aptly called the “CDCNC” thanks to its reliance on cast-off CD drive mechanisms for its running gear, [Paul McClay]’s creation is a great case study on what you can do without buying almost any new parts. It’s also an object lesson in not getting caught in standard design paradigms. Where most CNC mills mount the spindle vertically, [Paul] tilted the whole thing 90 degrees so the spindle lies on its side. Moving it back and forth on a pair of CD drive mechanisms is far easier than fighting gravity for control, and as a bonus the X- and Y-axes have minimal loading too. The video below shows the mill in action, and it’s easy to see how the horizontal arrangement really helps make this junk bin build into something special.

We think [Paul] did a great job of thinking around the problem with this build, and we’re glad he took the time to tip us off. Apparently it was the upcoming CNC on the Desktop Hack Chat that moved him to let us know about this build. Here’s hoping he drops by for the chat and shares his experience with us.

 

source https://hackaday.com/2020/08/25/mini-cnc-mill-goes-horizontal-to-reuse-cd-drives/

[Kryzer Channel] takes making a DIY RC car to a whole new level with this prop-driven electric car that is made almost entirely out of cardboard (YouTube video, also embedded below.) By attaching an electric motor with a push prop to the back of the car, [Kryzer] avoids the need for any kind of drive system or gearing. Steering works normally thanks to some scratch-built linkages, but the brake solution is especially clever.

Braking is done by having a stocky servo push a reinforced stub downward, out of a hole in the center of the car. This provides friction against the road surface. After all, on an RC car a functional brake is simply not optional. Cutting the throttle and coasting to a stop works for a plane, but just won’t do for a car.

Layers of corrugated cardboard and hot glue make up the bulk of the car body, and some of the assembly techniques shown off are really slick and make the video really worth a watch. For example, the construction of the wheels (starting around 2:24) demonstrates making them almost entirely out of cardboard, saturated with CA glue for reinforcement, with a power drill acting as a makeshift lathe for trimming everything down. A section of rubber inner tube provides the tire surface and a piece of hard plastic makes a durable hub. Wraps of thread saturated in CA glue, shown here, is another technique that shows up in several places and is used in lieu of any sort of fasteners.

The well-edited video (embedded below) is chock full of clever assembly and construction. Unsurprisingly, this is not [Krazer]’s first cardboard vehicle: their video channel has other impressive cardboard models and racers to show off.

Cardboard is an often under-rated prototyping material that offers loads of advantages. We’ve also seen the results of saturating paper products with CA glue before, like in this paper slug-flinging cardboard gun.

source https://hackaday.com/2020/08/25/prop-driven-cardboard-rc-car-doesnt-skimp-on-performance/

[Kryzer Channel] takes making a DIY RC car to a whole new level with this prop-driven electric car that is made almost entirely out of cardboard (YouTube video, also embedded below.) By attaching an electric motor with a push prop to the back of the car, [Kryzer] avoids the need for any kind of drive system or gearing. Steering works normally thanks to some scratch-built linkages, but the brake solution is especially clever.

Braking is done by having a stocky servo push a reinforced stub downward, out of a hole in the center of the car. This provides friction against the road surface. After all, on an RC car a functional brake is simply not optional. Cutting the throttle and coasting to a stop works for a plane, but just won’t do for a car.

Layers of corrugated cardboard and hot glue make up the bulk of the car body, and some of the assembly techniques shown off are really slick and make the video really worth a watch. For example, the construction of the wheels (starting around 2:24) demonstrates making them almost entirely out of cardboard, saturated with CA glue for reinforcement, with a power drill acting as a makeshift lathe for trimming everything down. A section of rubber inner tube provides the tire surface and a piece of hard plastic makes a durable hub. Wraps of thread saturated in CA glue, shown here, is another technique that shows up in several places and is used in lieu of any sort of fasteners.

The well-edited video (embedded below) is chock full of clever assembly and construction. Unsurprisingly, this is not [Krazer]’s first cardboard vehicle: their video channel has other impressive cardboard models and racers to show off.

Cardboard is an often under-rated prototyping material that offers loads of advantages. We’ve also seen the results of saturating paper products with CA glue before, like in this paper slug-flinging cardboard gun.

source https://hackaday.com/2020/08/25/prop-driven-cardboard-rc-car-doesnt-skimp-on-performance/

Schlieren imaging is a technique for viewing the density of transparent fluids using a camera and some clever optical setups. Density of a fluid like air might change based on the composition of the air itself with various gasses, or it may vary as a result of a sound or pressure wave. It might sound like you would need a complicated and/or expensive setup in order to view such things, but with a few common things you can have your own Schlieren setup as [elad] demonstrates.

His setup relies on a cell phone, attached to a selfie stick, with a spherical mirror at the other end. The selfie stick makes adjusting the distance from the camera to the mirror easy, as a specific distance from the camera is required as a function of focal length. For cell phone cameras, it’s best to find this distance through experimentation using a small LED as the point source. Once it’s calibrated and working, a circular field of view is displayed on the phone which allows the viewer to see any change in density in front of the mirror.

The only downside of this build that [elad] notes is that the selfie stick isn’t stiff enough to prevent the image from shaking around a little bit, but all things considered this is an excellent project that shows a neat and useful trick in the photography/instrumentation world that could be useful for a lot of other projects. We’ve only seen Schlieren imaging once before and it used a slightly different method of viewing the changing densities.

source https://hackaday.com/2020/08/25/schlieren-on-a-stick/

There was a time when any electronics student would have a slide rule hanging off their belt. By the 1970s, the slide rule changed over to an electronic calculator which was a pricy item. Today you can buy calculators at the dollar store. [JohnAudioTech] pulled out an old Radio Shack vacuum fluorescent display (VFD) calculator and found it didn’t work. Obviously, that means it is time to open it up.

It is fun to see one of these old devices opened up again. Consumer electronics with big through-hole ICs! Troubleshooting the device wound up being anti-climatic, as a broken wire to the battery compartment explained the whole thing.

As a teardown, though, this is a fun video. Not only are all the parts through-hole, but the PCB is clearly a manual layout with serpentine traces flowing across the board like some sort of art piece.

[John] even has a need hack for the calculator itself, if you happen to have one. Apparently, the calculator IC had a provision for a pi constant key, but there was no key for that function. Pressing the square root and 4 keys at the same time will trick the chip into providing pi anyway.

Another interesting item: [John] modified a cheap camera and removed the IR filter from it. Using that he was able to image the display’s cathode wire, which is normally difficult to see unaided.

There isn’t much need for a calculator now since your phone can easily do math ranging from a simple calculator app to symbolic math programs. But, like slide rules, we have a soft spot for these handheld computers.

If you don’t want vintage, an Arduino has plenty of power compared to these old machines. If, by chance, you want a modern calculator, they can also do plenty these days.

source https://hackaday.com/2020/08/24/an-old-calculator-lives-again/

When [0xRickSanchez] found some D-Link firmware he couldn’t unpack, he was curious to find out why. The firmware had a new encryption method which was doing its job of preventing tampering and static analysis. Of course, he had to figure out how to get around it and is documenting his work in a series of blog posts.

Looking at the entropy analysis showed the data to be totally random,  a good sign it was either encrypted or compressed. The target router cost about $200, but a similar cheaper router used the same encryption and thus this model became the hardware of choice for testing.

A console cable provided access to the router and an executable named imgdecrypt immediately caught his eye. Moving that file to a regular PC allowed the usual attack to see how it does its job.

You can follow along with part 2 which is in 2 different parts. The end result is on GitHub, but — honestly — the real adventure is in the story of how it came together.

We spend a lot of time thinking about reverse engineering things like this. We aren’t always looking at routers, either.

source https://hackaday.com/2020/08/24/hacking-d-link-firmware/

Phillips Ambilight technology is a curious thing, never quite catching on in the mainstream due to its proprietary nature. Consisting of an LED array that sits behind a television screen, it projects colours relevant to the content on screen to create a greater feeling of ambience. [Ed Chamberlain]’s reactive pixel lamps aim to do much the same thing in a more distributed way.

Each pixel lamp consists of a Wemos D1 controller fitted with an old-school 4-wire RGB LED. The components are placed in a 3D printed translucent cube, which serves as an attractive enclosure and diffuser. With WiFi connectivity on board, it’s possible to connect the individual cubes up to a Raspberry Pi serving as a Phillips Hue bridge thanks to DIYHue. Once setup, the lights can be configured as an Ambilight system within the Phillips Hue app.

It’s an impressive way to give a room reactive lighting on a budget, without resorting to costly off-the-shelf solutions. We’d love to see this expanded further, as we’re sure a room full of reactive lights would be truly a sight to behold. Other methods to recreate the Ambilight technology are possible, too. Video after the break.

source https://hackaday.com/2020/08/24/reactive-pixel-lamps-create-colourful-vibes-on-command/

Spectrophotometry is an important scientific tool, most commonly used in biology and chemistry. It’s a method to measure the amount of light absorbed by a chemical solution at various different wavelengths. While it’s typically the preserve of expensive lab equipment, [Daniel Hingston] built a rig to do the job at home.

The heart of the rig is a normal filament-based flashlight bulb, which produces good-quality white light containing all colors. A prism is then used to split the light into its component wavelengths, so that the sample can be tested across the whole light spectrum. The prism is rotated by a servo motor, which exposes the sample to the full rainbow, while an Arduino uses a light-dependent resistor to measure how much light makes it through the sample. Thus, the amount of light absorbed by the sample can be calculated, relative to calibrations made with no sample present.

It’s a simple build that can be achieved with fairly common materials, barring the prism which may need to be specially ordered. It would be a great way to teach highschool students about advanced scientific concepts, as well as showing them behind the curtain of how lab equipment works.

We see all kinds of DIY science gear around here; this lantern-based bioreactor is a great example. Video after the break.

source https://hackaday.com/2020/08/24/arduino-rig-does-spectrophotometry/

We have to hand it to this team, their entry for the 2020 Hackaday Prize is a classic pincer maneuver. A team from [The University of Auckland] in New Zealand and [New Dexterity] is designing a couple of gloves for both rehabilitation and human augmentation. One style is a human-powered prosthetic for someone who has lost mobility in their hand. The other form uses soft robotics and Bluetooth control to move the thumb, fingers, and an extra thumb (!).

The human-powered exoskeleton places the user’s hand inside a cabled glove. When they are in place, they arch their shoulders and tighten an artificial tendon across their back, which pulls their hand close. To pull the fingers evenly, there is a differential box which ensures pressure goes where it is needed, naturally. Once they’ve gripped firmly, the cables stay locked, and they can relax their shoulders. Another big stretch and the cords relax.

In the soft-robotic model, a glove is covered in inflatable bladders. One set spreads the fingers, a vital physical therapy movement. Another bladder acts as a second thumb for keeping objects centered in the palm. A cable system draws the fingers closed like the previous glove, but to lock them they evacuate air from the bladders, so jamming layers retain their shape, like food in a vacuum bag.

We are excited to see what other handy inventions appear in this year’s Hackaday Prize, like the thumbMouse, or how about more assistive tech that uses hoverboards to help move people?

source https://hackaday.com/2020/08/24/assistive-gloves-come-in-pairs/

What do you get when you add a thermal camera, a software-defined radio dongle, and a battery to a Raspberry Pi? If you are [saveitforparts] you make a tricorder for sniffing radio signals and viewing heat signatures. He admits, the videos (see below) aren’t exactly a “how-to” but it will still give you some ideas for your next build.

You can sense the frustration with some Linux configuration issues, but [saveitforparts] admits he isn’t a Linux or Raspberry Pi guru. Version 1 seemed to be a bit of a prototype, but version 2 is more polished. We still aren’t sure we’d see Spock carrying a case like that, but some 3D printing could spiff that right up.

Of course, a real tricorder is a McGuffin that does whatever the plot calls for. This one is a bit more practical, but it can monitor thermal and RF energy and could accommodate more sensors. This is a great example of a project that would have been very hard to do in the past but is much easier today. The availability of cheap computers and ready-made modules along with associated software open up many possibilities.

If you want to do your own Tricorder hacking you could take over a commercial model. Then again, there’s an official replica on its way that seems like it might have some similar features.

source https://hackaday.com/2020/08/24/raspberry-pi-makes-a-practical-tricorder/