Microcontrollers

2200 Articles

A Guide To Making The Right Microcontroller Choice

February 14, 2025 by 49 Comments

Starting a new microcontroller project can be pretty daunting. While you have at least a rough idea of where you want to end up, there are so many ways to get there that you can get locked into “analysis paralysis” and never get the project off the ground. Or arguably worse, you just throw whatever dev board you have in the junk bin and deal with the consequences.

While it’s hard to go wrong with relying on a familiar MCU and toolchain, [lcamtuf] argues in this recent guide to choosing microcontrollers that it’s actually not too much of a chore to make the right choice. Breaking the microcontroller universe down into three broad categories makes the job a little easier: simple process control, computationally intensive tasks, and IoT products. Figuring out where your project falls on that spectrum narrows your choices considerably.

For example, if you just need to read some sensors and run a few servos or solenoids, using something like a Raspberry Pi is probably overkill. On the other hand, a Pi or other SBC might be fine for something that you need wireless connectivity. We also appreciate that [lcamtuf] acknowledges that intangible considerations sometimes factor in, such as favoring a new-to-you MCU because you’ll get experience with technology you haven’t used before. It might not override technical considerations by itself, but you can’t ignore the need to stretch your wings once in a while.

There’s nothing earth-shattering here, but we enjoy think pieces like this. It’s a bit like [lcamtuf]’s recent piece on rethinking your jellybean op-amps.

A Tiny Computer With A 3D Printed QWERTY Keyboard

February 11, 2025 by 10 Comments

The ESP32 family are the microcontrollers which just keep on giving, as new versions keep them up-to-date and plenty of hackers come up with new things for them. A popular device is a general purpose computer with a QWERTY keypad, and the latest of many we’ve seen comes from [StabbyJack]. It’s a credit card sized machine whose special trick is that its keyboard is integrated in the 3D printing of its case. We’ve seen rubber membranes and push in keys, but this one has flexible print-in-place keys that line up on the switches on its PCB.

It’s not complete yet but the hardware appears to be pretty much there, and aside from that keyboard it has an ESP32-S3 and a 1.9″ SPI LCD. When finished it aims for an ambitious specification, with thermal camera and time-of-flight range finder hardware, along with an OS and software to suit. We like it a lot, though we suspect it might be a little small for our fingers.

If you like this project you may appreciate another similar one, and perhaps your version will need an OS.

RC Cars With First Person Video, All With An ESP32

February 6, 2025 by 8 Comments

Those little ESP32-CAM boards which mate the WiFi-enabled microcontroller with a small parallel-interface camera module have been with us for years, and while they are undeniably cool to play with, they sometimes stretch the available performance in trying to process and stream video. [Mattsroufe] has made a very cool project with one of them, not only managing to stream video from a small model car, but also to control the steering and motor by means of servos and a little motor driver.

Sadly it’s not entirely a stand-alone device, as the ESP32 streams video to a web server with some Python code to handle the controls. The server can aggregate several of them on one page though, for perhaps a little real-life quad-screen Mario Kart action if you have enough of the things. We can see that this idea has plenty of potential beyond the mere fun of driving a toy car around though, but to whet your appetite there’s a demo video below.

We’ve seen enough of the ESP32-cam before, but perhaps more as a photographic device.

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T1 Is A RISC-V Cray

February 6, 2025 by 16 Comments

The crux of most supercomputers is the ability to operate on many pieces of data at once — something video cards are good at, too. Enter T1 (short for Torrent-1), a RISC-V vector inspired by the Cray X1 vector machine.

T1 has support for features, including lanes and chaining. The chip contains a version of the Rocket Core for scalar operations, but there’s no official support for using it. The project claims you could easily replace that core with any other RISC-V CPU IP.

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BLE Rain Gauge Sips Water And Batteries

February 3, 2025 by 23 Comments

It isn’t that hard to make an electronic rain gauge if you have a steady source of power or you don’t mind changing batteries often. But [Matthew Ford] offers a third option: a simple device with a Bluetooth Low Energy (BLE) module that can get a few years of a pair of AA batteries.

The approach has several advantages. Batteries make the device self-contained, and changing them infrequently is an obvious win. In addition, the BLE allows the device to be wireless and send data directly to an Android device. Thanks to a WH-SP-RG rain gauge, there’s not much to that part. The smart part is an nRF52832 module and some minor parts. The phone side uses an off-the-shelf Android app.

In a project like this, it is critical to have timers that really put the CPU to sleep. [Matthew] had to modify the Arduino libraries to allow the lp_timer objects to make it to an hour. Without the modifications, the timer can only reach 8.5 minutes. Sure, you could stack them, but that means taking a power hit multiple times an hour which would affect battery life.

Not the most complex project, but more complexity would mean lower battery life, so — as they say — less is more. We couldn’t help but think that with rechargeable batteries and a small solar panel, this could last a very long time.

LoRa, of course, is another choice. You can make 3D print a tipping bucket device, too.

Antique-Style GPS Looks Like Steampunky Fun

February 1, 2025 by 14 Comments

These days, turn-by-turn GPS navigation isn’t considered special anymore. It’s in every smartphone and most cheap rental cars, and thus everybody expects you to figure out where you’re going. If you want a simpler and less robust navigation experience, you might like to try the rather fancy RadioScout.

The RadioScout is a build from [hardlyhumanfx]—a group of engineers and artists that collaborate on fun and whimsical projects. It looks like some kind of steampunk compass, and it kind of is—but at heart, it’s powered by GPS.

You program the RadioScout using the buttons on the front panel and a rotary phone dial to enter the latitude and longitude of your destination. It then uses an internal GPS receiver to compare that with your current location, and calculates a direct bearing to where you want to go. This bearing is displayed with a large compass-like needle run by a stepper motor, and you you can use it to guide yourself onwards.

It’s an attractive build that uses lots of neat parts. The team interfaced a microcontroller with a GPS receiver, a rotary dial, and 7-segment LEDs for the latitude and longitude display. The very real bell is neat, too. The whole thing is wrapped up in a brass and wooden case that would make you a star at just about any sci-fi convention. The build video is a little vague on the finer details, but experienced makers will be able to figure out how it all works.

You can actually buy a RadioScout if it’s something you must have, but one suspects the Hackaday set would probably prefer the homebrew route.

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A light-up clock displays the day of the week.

What Day Is It Again? Check The Clock

January 22, 2025 by 7 Comments

If you’re lucky enough to work from home, you’ll soon find that it presents its own set of challenges, mostly related to work/life balance. It can get so bad that you don’t know what day of the week it is. Really. Ask us how we know.

Rather than miss a meeting (or a day off), prolific hacker [Arnov Sharma] created this day of the week clock. It uses a customized LED driver board with seven sets of three LEDs, each driven by a MOSFET. Each MOSFET is controlled by a DFRobot Mini Beetle ESP32-C3. It runs on a 2200 mAh, 3.7 V lithium-ion battery.

While this is mostly PCBs, there are three printed parts that turn it into a displayable object. We really like the look of this clock — it has just the right amount of pizazz to it and reminds us of a and old movie marquee. Be sure to check out the great build instructions.

We love a good clock around here. In case you missed it, here is the latest from [Moritz v. Sivers] that uses a caustic lens to display the time.