The Future Of Hydrogen Power… Is Paste?

February 6, 2021 by Al Williams 142 Comments

We’ve been promised hydrogen-powered engines for some time now. One downside though is the need for hydrogen vehicles to have heavy high-pressure tanks. While a 700 bar tank and the accompanying fuel cell is acceptable for a city bus or a truck, it becomes problematic with smaller vehicles, especially ones such as scooters or even full-sized motorcycles. The Fraunhofer Institute wants to run smaller vehicles on magnesium hydride in a paste form that they call POWERPASTE.

The idea is that the paste effectively stores hydrogen at normal temperature and pressure, where it stays chemically locked until mixed with water. The researchers note that it will decompose around 250 °C, but while your motorcycle may seem hot when parked in the sun, it isn’t getting quite to 250C.

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PCB Bath Comes From Russia With Love

February 6, 2021 by Al Williams 19 Comments

[Ruvin Kub] likes magnets, a lot. Most of his projects feature some sort of magnet and his PC board agitation bath is no exception. You can see a video about the device, below. We’ll admit our Russian is pretty rusty, but if you ask YouTube nicely it will translate the Russian subtitles into whatever language you like.

One of the things we liked about the video was that he uses hydrogen peroxide, citric acid, and salt as an etchant. We’ve seen the same mix with vinegar or muriatic acid instead of citric acid. We aren’t sure what the actual translation is about why he doesn’t like ferric chloride, but YouTube says, “she’s too gloomy for my light souls.”

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Cap-Gun Lighter Built From Scratch

February 6, 2021 by Lewin Day 22 Comments

For most of us, a lighter is a cheap $2 plastic tool that serves a purpose, and little more. Some of us may go so far as to have a nice Zippo, or perhaps a windproof lighter for better outdoor performance. But if you’re a machinist, you could consider whipping yourself up something special, like this build by [W&M Levsha].

There’s plenty to love here for those who love making chips. The body is crafted out of brass and copper, soldered together by blowtorch. The lighter works by an unusual mechanism. The fluid tank is stuffed with cotton wool and filled with lighter fluid, which feeds a wick, which by itself, is fairly ordinary. However, ignition is via a spring-loaded aluminium hammer, which fires off a paper cap, igniting the wick. The flame can then be extinguished by blowing it out.

It’s a lighter that’s sure to be a conversation piece, though we wonder how welcome it’s cracking report will be at a quiet, reserved cigar bar. The mechanism may have more consumables than a typical lighter, but that’s the price paid to be truly unique. There are other creative designs out there too, like this lighter which uses a platinum catalyst for ignition. Video after the break.

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Super Mario Original Sound Tracks Get High Quality Remaster Thanks To Gigaleak

February 6, 2021 by Lewin Day 3 Comments

2020 saw many gigabytes of internal Nintendo data leaked on the broader internet. Known as the “Gigaleak”, it contained source codes and assets from many games. Using data from this leak, a group of enthusiasts has put together high-quality renditions of the SNES Super Mario World Original Sound Tracks (OST).

The work was made possible when source code from the Gameboy Advance remake of Super Mario World was found in the leaked data. The source code included the names of the samples, which were the same as were used in the original SNES game. This allowed the team to find the original samples amongst the gigabytes of leaked files.

We wondered what would be done with all that code, speculating that it would be a poison pill for the emulator scene. This type of hack wasn’t even on our radar and we’re delighted to see the project come to light. The reproduced songs have an altogether different quality than the original SNES soundtrack. This is largely due to the samples not having to be compressed or cut down to fit on a cartridge and work with the console’s sound chip. Other variances in the sound also come from the fact that unlike in the game, the samples in these renditions don’t match the play lengths in the original game.

Regardless of the changes, it’s interesting to hear a more full, rounded sound of these classic video game tunes. It reminds us somewhat of the later CD console era, when sound designers were able to break free of the limitations of earlier hardware. Of course, we still bow at the alter of chiptune, though — and this MIDI Gameboy mod is a great place to start if you’re curious. Video after the break.

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The Right Tools For The Job

February 6, 2021 by Elliot Williams 16 Comments

We’re knee-deep in new microcontrollers over here, from the new Raspberry Pi Pico to an engineering sample from Espressif that’s right now on our desk. (Spoiler alert, review coming out Monday.) And microcontroller peripherals are a little bit like Pokemon — you’ve just got to catch them all. If a microcontroller doesn’t have 23 UARTS, WiFi, Bluetooth, IR/DA, and a 16-channel 48 MHz ADC, it’s hardly worth considering. More is always better, right?

No, it’s not. Chip design is always a compromise, and who says you’re limited to one microcontroller per project anyway? [Francesco] built a gas-meter reader that reminded to think outside of the single-microcontroller design paradigm. It uses an ATtiny13 for its low power sleep mode, ease of wakeup, and decent ADCs. Pairing this with an ESP8266 that’s turned off except when the ATtiny wants to send data to the network results in a lower power budget than would be achievable with the ESP alone, but still gets his data up into his home-grown cloud.

Of course, there’s more complexity here than a single-micro solution, but the I2C lines between the two chips actually form a natural division of work — each unit can be tested separately. And it’s using each chip for what it’s best at: simple, low-power tasks for the Tiny and wrangling WiFi on the ESP.

Once you’ve moved past the “more is better” mindset, you’ll start to make a mental map of which chips are best for what. The obvious next step is combination designs like this one.

Proto-TV Tech Lies Behind This POV Clock

February 6, 2021 by Dan Maloney 11 Comments

If it weren’t for persistence of vision, that quirk of biochemically mediated vision, life would be pretty boring. No movies, no TV — nothing but reality, the beauty of nature, and live performances to keep us entertained. Sounds dreadful.

We jest, of course, but POV is behind many cool hacks, one of which is [Joe]’s neat Nipkow disk clock. If you think you’ve never heard of such a thing, you’re probably wrong; Nipkow disks, named after their 19th-century inventor Paul Gottlieb Nipkow, were the central idea behind the earliest attempts at mechanically scanned television. Nipkow disks have a series of evenly spaced, spirally arranged holes that appear to scan across a fixed area when rotated. When placed between a lens and a photosensor, a rudimentary TV camera can be made.

For his Nipkow clock, though, [Joe] turned the idea around and placed a light source behind the rotating disk. Controlling when and what color the LEDs in the array are illuminated relative to the position of the disk determines which pixels are illuminated. [Joe]’s clock uses two LED arrays to double the size of the display area, and a disk with rectangular apertures. The resulting pixels are somewhat keystone-shaped, but it doesn’t really distract from the look of the display. The video below shows the build process and the finished clock in action.

The key to getting the look right in a display like this is the code, and [Joe] put in a considerable effort for his software. If only the early mechanical TV tinkerers had had such help. [Jenny List] did a nice write-up on the early TV pioneers and their Nipkow disk cameras; we’ve also seen other Nipkow displays before, but [Joe]’s clock takes the concept to another level.

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Open-Source Thermostat Won’t Anger Your Landlord

February 6, 2021 by Anool Mahidharia 51 Comments

[Nathan Petersen] built a Hackable Open-Source Thermostat to smooth out temperature fluctuations caused by the large hysteresis of the bimetallic strip thermostat in his apartment. While it may be tempting to adjust the “anticipator” to take care of the problem or even replace the bimetallic thermostat with an electronic version, building your own thermostat from scratch is a good way to add to your project portfolio while making your way through college. Plus, he got to hone his hardware and software design chops.

The hardware is designed around the STM32, using a cheap, minimal variant since the device just needs to sense temperature and control the furnace in on-off mode. The TMP117 high-accuracy, low-power, temperature sensor was selected for temperature measurement since accuracy was an essential feature of the project. Dry-contact output for the furnace is via a normally-open solid state relay (opto-isolator). For the user interface, instead of going the easy-route and using an I²C/SPI OLED or LCD display, [Nathan] used three 7-segment LED displays, each driven by an 8-channel constant current driver. The advantage is that the display can be viewed from across the room, and it’s brightness adjusted via PWM. Temperature set-point adjustment is via a simple slide potentiometer, whose analog voltage is read by the micro-controller ADC. To remind about battery replacement, a second ADC channel on the micro-controller monitors the battery voltage via a voltage divider. The PCB components are mostly surface mount, but the packages selected are easy enough to hand solder.

[Nathan]’s Github repo provides the hardware and firmware source files. The board is designed in Altium, but folks using KiCad can use either the awesome Altium2KiCad converter or the online service for conversion. (The results, with some minor errors that can be easily fixed, are quite usable.) Serendipitously, his PCB layout worked like a charm the first time around, without requiring any rework or bodge wires.

The firmware is a few hundred lines of custom bare-metal C code, consisting of drivers to interface with the hardware peripherals, a UI section to handle the user interface, and the control section with the algorithm for running the furnace. [Nathan] walks us through his code, digging into some control theory and filtering basics. After making a few code tweaks and running the thermostat for some time, [Nathan] concludes that it is able to achieve +0.1°F / -0.5°F temperature regulation with furnace cycles lasting about 10-15 minutes (i.e. 4-6 cycles per hour). Obviously, his well insulated apartment and a decent furnace are also major contributing factors. Moving on, for the next version, [Nathan] wants to add data collection capabilities by adding some memory and SD card storage, and use an RTC to allow seasonal adjustments or time-based set-points.

This is his first attempt at a “functional’ useful project, but he does love to build the occasional toy, such as this POV Top.