microcontroller

389 Articles

Adding Capabilities To Inexpensive Solar Modules

May 15, 2026 by 4 Comments

Solar power has gotten cheap enough that putting up panels is among the cheapest ways of providing energy. This isn’t just the case for bulk electricity on a power grid, either; even small devices are easier and cheaper to power with solar than ever before. For example, landscape lighting which once relied on 12V or 24V DC wires all over one’s yard with a transformer and power supply hidden somewhere have partially been converted to simpler individual solar-powered lights now. These small devices can also be given additional capabilities as [Mauro] demonstrates.

In this case, [Mauro]’s goal was to add on-demand lighting to a solar-powered light which was otherwise motion-activated only. To do this, they added a NRF24L01+ radio inside the light’s housing paired with an STM32 microcontroller. This secondary system is largely separated from the existing control circuitry with the exception of being able to switch the lights and receiving its power from the same solar panel. [Mauro] also created a small library to help with communicating with these new modules, whether that’s using a home automation system like Home Assistant or some other method.

Although adding in a few capabilities to inexpensive solar lighting might seem simple on the surface, a project like this is a gateway to adding in all kinds of interesting features to things with built-in solar panels and lots of free space in their cases. The best example here is the addition of a Meshtastic node to one of these lights, making it convenient and stealthy, but we could also see adding in other remote hardware to a landscape lighting module like a gate sensor or a plant health monitoring system.

Rust Helps Make A $1 Handheld Console

May 1, 2026 by 25 Comments

These days, even an old Game Boy will set you back $100 or more, and a new handheld console will be many multiples of that. However, you can build a really cheap handheld gaming toy if you follow [Chris Dell’s] example.

In [Chris]’s own words, he used Rust to build a $1 handheld gaming console. How is that possible? Well, it all comes down to the CH32V003—a microcontroller cheaper than just about anything else out there. It sells for just 9 cents in bulk, and it’s no slouch either. The RISC-V device is a fully-fledged 32-bit chip running at 48 MHz, though with only 2 KB of RAM and 16 KB of flash. Still, that’s more than enough to make some little games. To this end, [Chris] paired the CH32V003 with an SSD1306 OLED display, and three tactile pushbuttons. He then whipped up some code in Rust with the aid of the ch32-hal project, implementing a neat platform game that ran at a healthy 25 fps.

The CH32V003 probably won’t be starring in a new handheld gaming revolution anytime soon. Still, it’s always interesting to see just what can be achieved with one of the cheapest microcontrollers on the market.

[Thanks to Kian Ryan for the tip!]

A Better Jogging Stroller

April 1, 2026 by 13 Comments

Although the jogging stroller is a fixture of suburban life, allowing parents the opportunity to get some exercise while letting their young children a chance for some fresh air, it would seem like the designers of these strollers have never actually gone for a jog. Requiring a runner to hold their hands at fixed positions can be incredibly uncomfortable and disrupts most people’s strides and cadence — so [John] attempted to solve the problem after finding one of these strollers on the secondhand market.

While there are some purpose-built strollers that attempt to address these issues, they can be pricey. Rather than shell out for a top-dollar model, [John] got to work with his 3D printer and created a prototype device that allows him to attach the stroller at his waist while leaving his hands free. There were a few problems to overcome here, the first of which would cause the device to buckle under certain loading situations. This was solved with some small pieces of rope which act as flexible bump stops, keeping the hinge mechanism from binding up. Another needed to be solved with practice, which was that it took some time to be able to steer the stroller without using one’s hands.

As an added bonus, [John] also included a system that tracks the distance the stroller has traveled. Using a hall effect sensor and a magnet attached to the wheel, a small microcontroller is able to quickly calculate distance and display it on a tiny screen mounted near the handlebars. Although smartphones are handy, their GPS systems can be surprisingly inaccurate, so a system like this can be a better indicator since it’s being directly measured. All in all, not a bad few upgrades to a secondhand stroller.

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Analog Video From An 8-Bit Microcontroller

March 21, 2026 by 24 Comments

Although the CRT has largely disappeared from our everyday lives, there was a decades-long timeframe when this was effectively the only display available. It’s an analog display for an analog world, and now that almost everything electronic is digital, these amazing pieces of technology are largely relegated to retro gaming and a few other niche uses. [Maurycy] has a unique CRT that’s small enough to fit in a handheld television, but since there aren’t analog TV stations anymore, he decided to build his own with nothing but an 8-bit microcontroller and a few other small parts.

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Driving A DAC Real Fast With A Microcontroller

January 21, 2026 by 17 Comments

Normally, if you want to blast out samples to a DAC in a hurry, you’d rely on an FPGA, what with their penchant for doing things very quicky and in parallel. However, [Anabit] figured out a way to do the same thing with a microcontroller, thanks to the magic of the Raspberry Pi Pico 2.

The design in question is referred to as the PiWave 150 MS/s Bipolar DAC, and as the name suggests, it’s capable of delivering a full 150 million samples per second with 10, 12, or 14 bits of resolution. Achieving that with a microcontroller would normally be pretty difficult. In regular linear operation, it’s hard to clock bits out to GPIO pins at that sort of speed. However, the Raspberry Pi Pico 2 serves as a special case in this regard, thanks to its Programmable I/O (PIO) subsystem. It’s a state machine, able to be programmed to handle certain tasks entirely independently from the microcontroller’s main core itself, and can do simple parallel tasks very quickly. Since it can grab data from RAM and truck it out to a bank of GPIO pins in a single clock cycle, it’s perfect for trucking out data to a DAC in parallel at great speed. The Pi Pico 2’s clock rate tops out at 150 MHz, which delivers the impressive 150 MS/s sample rate.

The explainer video is a great primer on how this commodity microcontroller is set up to perform this feat in detail. If you’re trying for accuracy over speed, we’ve explored solutions for that as well. Video after the break.

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TV Remote Uses Floppy Disks

January 19, 2026 by 9 Comments

Famously, the save icon on most computer user interfaces references a fairly obsolete piece of technology: the venerable floppy disk. It’s likely that most people below the age of about 30 have never interacted with one of these once-ubiquitous storage devices, so much so that many don’t recognize the object within the save icon itself anymore. [Mads Chr. Olesen]’s kids might be an exception here, though, as he’s built a remote control for them that uses real floppy disks to select the programming on the TV.

This project partially began as a way to keep the children from turning into zombies as a result of the modern auto-play brainrot-based economies common in modern media. He wanted his kids to be able to make meaningful choices and then not get sucked into these types of systems. The floppy disk presents a perfect solution here. They’re tangible media and can actually store data, so he got to work interfacing a real floppy disk drive with a microcontroller. When a disk is inserted the microcontroller wakes up, reads the data, and then sends out a command to stream the relevant media to the Chromecast on the TV. When the disk is removed, the microcontroller stops play.

Like any remote, this one is battery powered as well, but running a microcontroller and floppy disk drive came with a few challenges. This one is powered by 18650 lithium cells to help with current peaks from the drive, and after working out a few kinks it works perfectly for [Mads] children. We’ve seen a few other floppy disk-based remote controls like this one which replaces the data stored on the magnetic disc with an RFID tag instead.

Keep An Eye On Your Air-Cooled Engine

October 23, 2025 by 24 Comments

There was a time, long ago, when passenger vehicles used to be much simpler than they are today. There were many downsides of this era, safety chief among them, but there were some perks as well. They were in general cheaper to own and maintain, and plenty could be worked on with simple tools. There’s perhaps no easier car to work on than an air-cooled Volkswagen, either, but for all its simplicity there are a number of modern features owners add to help them with these antiques. [Pegor] has created his own custom engine head temperature monitor for these vehicles.

As one could imagine with an air-cooled engine, keeping an eye on the engine temperature is critical to ensuring their longevity but the original designs omitted this feature. There are some off-the-shelf aftermarket solutions but this custom version has a few extra features that others don’t. It’s based on a ATMega32u4 microcontroller and will work with any K-type thermocouple, and thanks to its open nature can use a wide array of displays. [Pegor] chose one to blend in with the rest of the instrumentation on this classic VW. The largest issue that needed to be sorted out was around grounding, but a DC-DC converter created an isolated power supply for the microcontroller, allowing the thermocouple to be bonded to the grounded engine without disrupting operation of the microcontroller.

The finished product looks excellent and does indeed blend in to the dashboard more than the off-the-shelf temperature monitor that was in use before. The only thing that is planned for future versions is a way to automatically dim the display when the headlights are on, as [Pegor] finds it a little bright at night. We also enjoy seeing anything that helps these antiques stay on the road more reliably as their modern descendants don’t have any of the charm or engineering of these classics.