[memestra] is a teacher whose life has become a series of videoconferences over the last year or so. With all the classes and meetings, they spend the whole day switching between either Zoom, Teams, or Meet. If anyone needs a single piece of hardware to control them all, it’s [memestra]. Well, and every other teacher out there.
The hardware — an Arduino Pro Micro and some buttons — should come as no surprise, except for maybe [memstra]’s use of a resistor network for the LEDs. Still, there’s a lot to like about this little box, starting with the enclosure. That’s not milled or laser-cut metal — each side is a PCB, and they’re all soldered together into a box.
We especially like the top panel, which fits down over the PCB that all the components are soldered to. Each of the non-volume buttons has multiple functions that are accessed by pressing, long pressing, or double pressing. But even the volume buttons do double duty: press them together to mute and un-mute. If [memestra] ever forgets which button does what and how, there’s a handy reference table silkscreened on the bottom panel.
In true teacher fashion, [memestra] has written comprehensive instructions for anyone looking to build a similar device. The heavily-commented code should make it a cinch to drop in keyboard shortcuts for Discord or anything else you might be using, though it’s worth noting that this box is optimized for the desktop apps and not the browser-based versions.
Make the move to a split keyboard and the first thing you’ll notice is that you have all this real estate between the two halves. (Well, as long as you’re doing it right). This is the perfect place to keep your cat, your coffee cup, or in [Jacek]’s case, your fantastic DIY trackball mouse.
Don’t be fooled by the orange plastic base — all the electronics are rolled up inside that big sexy ball, which [Jacek] printed in two halves and glued together. Inside the ball there’s an Adafruit Feather nRF52840 Sense, which has an onboard accelerometer, gyroscope, and magnetometer. As you’ll see in the video after the break, the Feather takes readings from these and applies a sensor-fusing algorithm to determine the ball’s orientation in 3D space before sending its position to the computer. To send the click events, [Jacek] baked some mouse buttons into the keyboard’s firmware. Among the other Feather sensors is a PDM MEMS microphone, so detecting taps on the ball and translating them to clicks is not out of the question for a future version.
Here comes the really clever part: there are two reed switches inside the ball. One is used as a power switch, and the other is for setting the ‘up’ direction of the trackball. The ball charges wirelessly in a 3D printed base, which also has a small neodymium magnet for activating the reed switches. Check out the demo after the break, which shows [Jacek] putting the trackball through its paces on a mouse accuracy testing program.
We wouldn’t be where we are today without Mrs. Coldiron’s middle school typing class. Even though she may have wanted to, she never did use negative reinforcement to improve our typing speed or technique. We unruly teenagers might have learned to type a lot faster if those IBM Selectrics had been wired up for discipline like [3DPrintedLife]’s terrifying, tingle-inducing typist trainer keyboard (YouTube, embedded below).
This keyboard uses capsense modules and a neural network to detect whether the user is touch-typing or just hunting and pecking. If you’re doing it wrong, you’ll get a shock from the guts of a prank shock pen every time you peck the T or Y keys. Oh, and just for fun, there’s a 20 V LED bar across the top that is supposed to deter you from looking down at your hands with randomized and blindingly bright strobing light.
Twenty-four of the keys are connected in groups of three by finger usage — for example Q, A, and Z are wired to the same capsense module. These are all wired up to a Raspberry Pi Zero along with the light bar. [3DPrintedLife] was getting a lot of cross-talk between capsense modules, so they solved the problem in software by training a TensorFlow model with a ton of both proper and improper typing data.
We love the little meter on the touchscreen that shows at a glance how you’re doing in the touch typing department. As the meter inches leftward, you know you’re in for a shock. [3DPrintedLife] even built in some games that use pain to promote faster and more accurate typing. Check out the build video after the break, but don’t say we didn’t warn you about the strobing lights.
For hackers on a tight budget or with limited bench space, a USB oscilloscope can be a compelling alternative to a dedicated piece of hardware. For plenty of hobbyists, it’s a perfectly valid option. But while the larger discussion about the pros and cons of these devices is better left for another day, there’s one thing you’ll definitely miss when the interface for your scope is a piece of software: the feel of physical buttons and knobs.
But what if it doesn’t have to be that way? The ScopeKeypad by [Paul Withers] looks to recreate the feel of a nice bench oscilloscope when using a virtual interface. Is such a device actually necessary? No, of course not. Although one could argue that there’s a certain advantage to the feedback you get when spinning through the detents on a rotary encoder versus dragging a slider on the screen. Think of it like a button box for a flight simulator: sure you can fly the plane with just the keyboard and mouse, but you’re going to have a better time with a more elaborate interface.
The comparison with a flight simulator panel actually goes a bit deeper, since that’s essentially what the ScopeKeypad is. With an STM32 “Blue Pill” microcontroller doing its best impression of a USB Human Interface Device, the panel bangs out the prescribed virtual key presses when the appropriate encoder is spun or button pressed. The project is designed with PicoScope in mind, and even includes a handy key map file you can load right into the program, but it can certainly be used with other software packages. Should you feel so inclined, it could even double as a controller for your virtual spaceship in Kerbal Space Program.
Interested in making a custom keyboard, but unsure where to start? Good news, because [Jared]’s build log for an adorable “2% Milk” two-key mini-keyboard covers everything you need to know about making a custom keyboard, including how to add optional RGB lighting. The only difference is that it gets done in a smaller and cheaper package than jumping directly in with a full-size DIY keyboard.
[Jared] is definitely no stranger to custom keyboard work, but when he saw parts for a two-key “2% Milk” keyboard for sale online, he simply couldn’t resist. Luckily for us, he took plenty of photos and his build log makes an excellent tutorial for anyone who wants to get into custom keyboards by starting small.
The hardware elements are clear by looking at photos, but what about the software? For that, [Jared] uses a Teensy Pro Micro clone running QMK, an open source project for driving and configuring custom input devices. QMK drives tiny devices like the 2% Milk just as easily as it does larger ones, so following [Jared]’s build log therefore conveys exactly the same familiarity that would be needed to work on a bigger keyboard, which is part of what makes it such a great project to document.
Folks who like the take the old Amiga out for the occasional Sunday drive usually do it because they have wistful memories of the simpler times. Back when you could edit documents or view spreadsheets on a machine that had RAM measured in kilobytes instead of gigabytes. But even the most ardent retro computer aficionado usually allows for a bit of modern convenience.
Enter the mouSTer. This tiny device converts a common USB HID mouse into something older computers can understand. It even supports using Sony’s PlayStation 4 controller as a generic game pad. While the firmware is still getting tweaked, the team has confirmed its working on several classic machines and believe it should work on many more. Considering the prices that some of these old peripherals command on the second hand market, using a USB mouse or controller on your vintage computer isn’t just more convenient, but will likely be a lot cheaper.
Confirmed retrocomputing superfan [Drygol] is a member of the team working on mouSTer, and in a recent post to his retrohax blog, he talks a bit about what’s happened since his last update over the summer. He also talks a bit about the challenges they’ve faced to get it into production. Even if you’re not into poking around on vintage computers, there are lessons to be learned here about what it takes to move from a handful of prototypes to something you can actually sell to the public.
We especially liked the details about the mouSTer enclosure, or lack thereof. Originally [Drygol] says they were going to have the cases injection molded, but despite initial interest from a few companies they talked to, nobody ended up biting because it needed to be done with relatively uncommon low pressure injection. While 3D printing is still an option, the team ended up using clear heatshrink tubing to create a simple conformal protective shell over the electronics. Personally we think it looks great like this, but it sounds like this is only a temporary solution until something a bit more robust can be implemented.
It’s 2021, shouldn’t all of our devices be able to pull the power they need from the ether? [Sasa Karanovic] certainly thinks so, which is why he recently took it upon himself to add wireless charging capabilities to his desktop computer peripherals. The Qi transmitter and receiver modules are relatively cheap and easy to come by, the trick is in getting them installed.
For the keyboard, [Sasa] took the path of least resistance. The receiver coil lives inside a little 3D printed box attached to the back, and power is routed through a hacked up right-angle USB cable. It’s a simple addition that doesn’t make any permanent changes to the keyboard; perfect for those who don’t want to risk toasting their gear.
But that wasn’t really an option for the mouse. Obviously the Qi hardware would have to go on the inside, but at a glance it was clear there wasn’t enough room to mount the stock coil. So [Sasa] pulled the original coil apart and rewound it around a small 3D printed jig. This resulting coil was perfectly sized to fit inside the flat area on the left side of the mouse with no apparent degradation in charging ability. Wiring the module up to an unpopulated pad on the PCB allowed him to easily inject the 5 V output into the device’s existing charging circuitry.