Microcontrollers

2285 Articles

The Keyboard You Really Don’t Need Or Want

May 6, 2021 by 48 Comments

Most people think of a keyboard as a flat, vaguely rectangular thing with around 100ish different keys. A mechanical keyboard enthusiast would heartily disagree and point out various tenkeyless, 75%, 60%, or 40% keyboards that strip down the idea of what a keyboard is by taking keys out. [Stavros Korokithakis] takes that notion and turns it on its side by creating the five-button vertical keyboard known as Keyyyyyyyys.

This keyboard, or keystick, is designed to be onehanded and to be eye-contact-free. With just five keys, it makes heavy use of chording to output all the characters needed. It has a maximum of 32 possible states and taking out pressing nothing as a no-op leaves 31 possible key combinations. So [Stavros] had to get creative and laid out the letters according to their frequency in the English language. The brains of Keyyyyyyyys is the ubiquitous ESP32, emulating a Bluetooth keyboard while being wrapped in a simple 3d printed box. The code is hosted on GitLab.

If you don’t know how hard it is to learn a five-key chording keyboard from scratch, definitely check out [Stavros]’ video embedded below. “C’mon h.” We have heard reports that you can learn these things, though.

While this five-button keyboard may seem small, this two-button keyboard still has it beat by three keys. A one-button keyboard is just a morse code keyboard, and we are looking forward to a wireless Bluetooth version. Continue reading “The Keyboard You Really Don’t Need Or Want” →

Modified Microwave Cures Resin Parts With Style

May 5, 2021 by 18 Comments

Once you make the leap to resin-based 3D printing, you’ll quickly find that putting parts out in the sun to cure isn’t always a viable solution. The best way to get consistent results is with a dedicated curing chamber that not only rotates the parts so they’re evenly exposed to the light, but allows you to dial in a specific curing time. A beeper that goes off when the part is done would be handy as well. Wait, this is starting to sound kind of familiar…

As you might expect, [Stynus] isn’t the first person to notice the similarities between an ideal UV curing machine and the lowly microwave oven. But his conversion is certainly one of the slickest we’ve ever seen. The final product doesn’t look like a hacked microwave so much as a purpose-built curing machine, thanks in large part to the fact that all of the original controls are still functional.

The big break there came when [Stynus] noticed that the control panel was powered by a one-time programmable PIC16C65B microcontroller. Swapping that out for the pin-compatible PIC16F877A opened up the possibility of writing custom firmware to interface with all the microwave’s original hardware, he just needed to reverse engineer how it was all wired up. It took some time to figure out how the limited pins on the microcontroller ran the LED display and read the buttons and switches at the same time, but we’d say the final result is more than worth the work.

With full control over the microwave’s hardware, all [Stynus] had to do was strip out all the scary high voltage bits (which were no longer functional to begin with) and install an array of UV LEDs. Now he can just toss a part on the plate, spin the dial to the desired curing time, and press a button. In the video below, you can see he’s even repurposed some of the buttons on the control panel to let him do things like set a new default “cook” time to EEPROM.

Compared to the more traditional fused deposition modeling (FDM) 3D printers, resin printing requires a lot of additional post-processing and equipment. You don’t necessarily have to gut your microwave just to cure your prints, but you’d be wise to fully consider your workflow will look like before pulling the trigger on that shiny new printer.

Continue reading “Modified Microwave Cures Resin Parts With Style” →

Looks Like A Pi Zero, Is Actually An ESP32 Development Board

April 30, 2021 by 34 Comments
ATMegaZero ESP32- S2, showing optional color-coded 40-pin header (top)

The ATMegaZero ESP32-S2 is currently being funded with a campaign on GroupGets, and it’s a microcontroller board modeled after the Raspberry Pi Zero’s form factor. That means instead of the embedded Linux system most of us know and love, it’s an ESP32-based development board with the same shape and 40-pin GPIO header as the Pi Zero. As a bonus, it has some neat features like a connector for inexpensive SSD1306 and SH1106-based OLED displays.

Being able to use existing accessories can go a long way towards easing a project’s creation, and leveraging that is one of the reasons for sharing the Pi Zero form factor. Ease of use is also one of the goals, so the boards will ship with CircuitPython (derived from MicroPython), and can also be used with the Arduino IDE.

If a microcontroller board using the Pi Zero form factor looks a bit familiar, you might be remembering the original ATMegaZero which was based on the Atmel ATMega32U4, but to get wireless communications one needed to attach a separate ESP8266 module. This newer board keeps the ATMegaZero name and footprint, but now uses the Espressif ESP32-S2 to provide all the necessary functions.

CircuitPython has been a feature in a wide variety of projects and hacks we’ve seen here at Hackaday, and it’s a fine way to make a microcontroller board easy to use right out of the box.

RGB LED Rings Teach Old Dash New Tricks

April 29, 2021 by 9 Comments

We’ve seen several so-called “digital dash” upgrades over the years that either augment, or completely replace, a vehicle’s original dashboard indicators with new displays. Whether its seven segment LEDs or a full-on graphical interface powered by the Raspberry Pi, the end result is the same: a dashboard that looks wildly different than it did when the car rolled off the assembly line.

But this LED dashboard project from [Flyin’ Miata] takes a slightly different approach. Rather than replace the analog gauges entirely, rings of RGB LEDs of the same diameter were placed behind their matte black faces. When the LEDs are off you’d never notice them, but once they kick on, the light is clearly visible through the material.

LEDs can easily shine through the gauge face.

So far, it looks like most of the work seems to have been put into the tachometer. The firmware running on the CAN equipped Adafruit Feather M4 can do things such as light up a dynamic redline based on current engine temperature. It will also light up the LEDs to follow the analog gauge as it moves around, which might not have much practical application, but certainly looks cool.

On the speedometer side, the LEDs seem to be used primarily as warning indicators. As demonstrated in the video below, the whole gauge can light up bright red to indicate a critical situation such as low oil pressure. If you wanted to, the system could also be configured with different colors corresponding to various possible fault conditions.

Compared to some of the more aggressive dashboard updates we’ve seen, this is an interesting compromise that helps retain the look of the original instrumentation. Of course, depending on the make and model of the car, you might be able to sneak in a small LCD screen without anyone noticing.

Continue reading “RGB LED Rings Teach Old Dash New Tricks” →

Where We’re Going, We Don’t Need Keycaps

April 26, 2021 by 14 Comments

Just when we thought we’d seen the peak of ergonomic, split keyboards, along comes [Peter Lyons] with the Squeezebox — an adjustable, column-staggered, streamlined beauty with 21 keys per hand. Much like the Kinesis Advantage and the Dactyl, the user’s fingers are allowed to dangle comfortably and stay in their naturally curled position, moving as little as possible between keys, rows, and columns. But the Squeezebox goes a few steps farther to reduce finger travel.

For starters, each column of keys is adjustable on the fly in the Y-direction by loosening the screw and sliding it until it’s just right. The columns are also adjustable in the Z-direction, but for now, this requires reprinting a few parts. In case you didn’t notice, the grid is pretty tightly packed, and those low-profile Kailh choc switches are naked to the world, mostly because keycaps wouldn’t fit anyway.

At that angle, there’s no reaching required at all between the middle and bottom rows. The 100° corner that they form both invites and supports chording — that’s pressing multiple keys simultaneously to do some action. There’s no real need to reach for the top row, either, because [Peter] merely moves his finger upward in the Z-direction a little bit to hit those. The similarly-angled thumb clusters are chord-able as well, and their position relative to the mainland is adjustable thanks to a grid of holes that are meant for threaded inserts. Genius!

For the next version, [Peter] plans to bring the three sets of thumb cluster switches closer together, and arrange them like a tri-fold science fair display board. Be sure to check out the super cool but somewhat impossible-to-solder prototypes in the build log, and stay for more stuff in the huge build gallery. Typing demo is after the break.

Still too much travel for your taste? How about a 5-way for each finger?

Continue reading “Where We’re Going, We Don’t Need Keycaps” →

Build An ESP32 Stock Ticker To Watch Your GME Gains

April 26, 2021 by 14 Comments

Meme investing is all the rage these days, and what better way to get in on the loss fun than with your very own old-timey mechanical stock ticker? Unfortunately, they’re about as expensive and rare as you might expect for a piece of Victorian-era electronics. Lucky for us, [secretbatcave] has shown that you can put together a functional look-alike that costs about as much as a GameStop (GME) share was worth before it started heading to the Moon.

This might seem like an ambitious project, but in actuality the machine only has a few moving parts. There’s a stepper motor to feed the paper, another to spin an inked embossing wheel, and a couple of solenoids attached to a pusher plate. Rather than trying to move the heavy wheel, the pusher plate smashes the paper up into it. The fact that this produces a satisfying “clack” sound as each character is printed is just an added bonus.

Extending the base to hold the solenoids.

To sell the look, [secretbatcave] put the whole mechanism inside a tall glass dome from IKEA. The matching wooden base was extended so the pusher plate solenoids could fit inside, after which it was dunked in ink and sprayed with a gloss sealer to give it that shiny black finish people seemed to love in the 1900s. With the addition of an engraved brass nameplate, it looks like the machine fell out of a time warp.

In terms of electronics, there’s an ESP32, a pair of stepper motor controllers, and a relay for the solenoids. As of right now it all lives in a rather utilitarian box that’s tethered to the ticker, but we’re sure the lot could get tucked under the base with the help of a custom PCB should you be so inclined.

With an ESP32 at the helm, the ticker could easily be configured to print out whatever data it receives over the network or picks up from MQTT. With hardware like this and a pair of Diamond Hands, those tendies are as good as yours.

Continue reading “Build An ESP32 Stock Ticker To Watch Your GME Gains” →

Forth Module The Size Of A Stick Of Gum

April 25, 2021 by 27 Comments

Australian engineer [John Catsoulis] developed a small module called the Scamp2 dedicated to running Forth. The focus of his Udamonic project was not only to highlight Forth, but to make a module which was easy to use and doesn’t require any IDE on your computer. According to the website, these modules have found their niche in education as well as rapid prototyping for product development. His site has some good resources, including several Scamp/Forth example applications such as a model train controller or adding a real-time clock module.

The core of the module is a Microchip PIC24F64GB202 MCU with 64K Flash and 8K RAM. Of this, Forth takes up only 20K of Flash and 2K of RAM. [John] is using FlashForth, a version of Forth which came from [Mikael Nordman] at the University of Queensland almost ten years ago. FlashForth has been implemented on a wide variety of PIC and AVR ATmega processors and has apparently developed quite a following in Australia and elsewhere.

We estimate from the photo that the Scamp is about 80 mm long, just slightly longer than a standard piece of MIL-A-A-20175A Type II chewing gum ( 73 mm ). You can use it as-is, or with the header pins installed, the Scamp can be plugged into a breadboard for easy hacking. Regarding the interfacing of Scamp to other equipment, [John] says “Writing software to use other hardware is very easy, and fun.” We like his attitude.

Here is some more information from his Hackaday.io project page, and he also has a Tindie site. If you want a good overview of using Forth in embedded systems, check out Forth: The Hacker’s Language by our own Forth-guru [Elliot Williams]. Thanks to [Stephen Walters] for sending in the tip.

Continue reading “Forth Module The Size Of A Stick Of Gum” →