A Customizable Open Source Mechanical Numpad

May 13, 2019 by Tom Nardi 11 Comments

Mechanical keyboards with reduced key counts are all the rage these days, but while those streamlined input devices might look cool on your desk, there are times when the traditional number pad or navigation keys are quite handy. Rather than just going without, [Mattia Dal Ben] decided to put together his own mechanical auxiliary input device for when the main board just isn’t cutting it.

[Mattia] is calling his creation the YamPAD, which stands for Yet Another Mechanical numPAD. One of the major goals for the project is to produce a design that’s easy for others to replicate and customize. His PCB has a socket designed to fit an Arduino Pro Micro, which combined with the QMK firmware, offers a wide array of configuration options. All that’s left is to add in the Cherry MX switches and some 1N4148 diodes.

But if you want to take things a little further, [Mattia] has that covered as well. The PCB design has provisions for RGB LED back-lighting should you find yourself in need of crunching some numbers in the dark. There’s even a spot for a 0.91″ OLED display if you really want to take things to the next level.

As of right now, the YamPAD is just a bare PCB, but [Mattia] is planning to design a 3D printed enclosure for it soon. The sketches he’s done so far depict a printed case which we think bears more than a passing resemblance to a Wii Fit Balance Board, but of course being a fully open source project, you’ll be free to design your own case based on the PCB’s dimensions. It would be interesting to see what other kind of customization the community might come up with once the design is finalized.

If you like the idea of the YamPAD, you might also want to check out the kbord we covered back in 2017. If you want to see the full keyboard done in this DIY open hardware style, there are already some choice entries into the field.

A 32-bit Boost For Your 3D Printer

May 10, 2019 by Tom Nardi 52 Comments

It might not be the kind of thing you’ve given much thought to, but if you’ve ever used a desktop 3D printer, it was almost certainly being controlled by an 8-bit CPU. In fact, the common RAMPS controller is essentially just a motor driver shield for the Arduino Mega. Surely we can do a bit better than that in 2019?

For his entry into this year’s Hackaday Prize, [Robert] is working on a 32-bit drop-in replacement board which would allow 3D printer owners to easily upgrade the “brain” of their machines. Of course, there are already a few 32-bit control boards available on the market, but these are almost exclusively high-end boards which can be tricky to retrofit into an older machine. It should also go without saying that they aren’t cheap.

With this board, [Robert] is hoping to create a simpler upgrade path for 8-bit printer owners. Being small and cheap is already a pretty big deal, but perhaps equally importantly, his board is running the open source Marlin firmware. Marlin powers the majority of 8-bit desktop 3D printers (even if their owners don’t necessarily realize it) so sticking with it means that users shouldn’t have to change their software configuration or workflow just because they’ve upgraded their controller.

The board is powered by a 72 MHz STM32F103 chip, and uses state-of-the-art Trinamic TMC2208 stepper drivers to achieve near silent operation. The board has an automatic cooling fan to help keep itself cool, and with an XT60 connector for power, it should even be relatively easy to take your printer on the go with suitably beefy RC batteries.

The Two-Dimensional Stepper Motor

May 9, 2019 by Brian Benchoff 20 Comments

Over on hackaday.io and deep in the Hackaday Prize, a lot of cool people are playing around with the possibilities of putting coils in printed circuit boards. On the face of it, it makes sense: drawing spirals on a PCB gets you an electromagnet. This allows you to do all sorts of crazy things. You can make miniature model maglev trains using the track as a motor. Someone built a wearable Tesla coil.

The latest build to show off the possibilities of motors etched on PCBs is [bobricius]’ micro manipulator. It’s a 100 mm square board capable of moving a small magnet around the surface. The point? Well, if you have to ask that question you’re really never going to get the point.

The design of this stepper motor is simply two coils of wire, with the X axis of the grid placed on the top copper layer of the PCB and the Y axis on the bottom copper layer. There are four poles to each of these coils, and they plug right into a standard stepper driver, so to control this board all you need is a basic Arduino and a motor shield. Or a RepRap board, take your pick, you probably have something sitting around in a junk drawer.

In the test of this board, the stepper motor can move small rare earth magnets around quickly and with high repeatability. As for what use this PCB stepper motor has, if you have to ask that question, you’ll never know. Also, because it looks cool.

Continue reading “The Two-Dimensional Stepper Motor” →

Pushing 3D Printed Wheels And Transmissions To The Limit

May 8, 2019 by Brian Benchoff 19 Comments

What do you do if you want a robot with great mobility? Walking is hard, and wheels are good enough, especially if you use the ‘wheels within wheels’ Mecanum setup. But you need torque, too. That’s what makes this entry into the Hackaday Prize so fantastic. It’s a Mecanum wheel of sorts, with an integrated gear set that produces a phenomenal amount of torque using a small, cheap stepper motor.

The wheel itself if 3D printed and fully parametric, using nylon weed wacker filament for the treads. This allows the wheel to scoot back and forth like a Mecanum wheel, or at the very least like one of those hyper mobile wheeled robots you see from time to time. It goes backwards, forwards, and side to side, and also has a zero turn radius.

A 3D printed Mecanum wheel is great, but how on earth do you drive it? That problem is solved with this hybrid planetary/strain-wave 3D-printed gear set. [Daren] has created a very compact ‘single’ stage gear set that fits right on top of a stepper motor. It’s thin, flat, and has a gear reduction of about 66:1. That’s a lot of torque in a very small package. Both of these projects are combined, and together they represent a freaky wheel with a lot of torque.

Even though [Daren] doesn’t have a robot in mind for this build, these are most certainly the building blocks of a fantastic robot, and a great entry in the Hackaday Prize.

Continue reading “Pushing 3D Printed Wheels And Transmissions To The Limit” →

Building Keyboards With Resin Printers

May 7, 2019 by Brian Benchoff 12 Comments

Aside from putting a whole lot of tact switches on a board, no one has quite figured out how to make very small keyboards for wearable projects. [Madaeon] might have the answer, and it’s using a resin-based 3D printer to create a flexible keyboard without silicone.

The world of small keyboards is filled with what are effectively the squishy parts of a remote control. This uses a piece of silicone and tiny carbon ‘dots’ on the underside of each button. Press the button, and these carbon dots bridge two traces on a PCB, closing a switch. No one has yet mastered home-casting silicone, although the people behind the ESP32 WiPhone have been experimenting with aluminum molds.

Instead of going down the path of casting and curing silicone, [Madaeon] decided to use 3D printing, specifically resin 3D printing, using a very flexible resin. The build process is what you would expect — just some button-shaped objects, but this gets clever when it comes to bridging the connections on the keyboard matrix. This is done with conductive paint, carefully applied to the underside of each button.

Right now this is a viable means of getting a tiny keyboard easily. The color is a garish pink, and the labels on each button aren’t quite as visible as anyone would like, but the latter can be fixed with silkscreening, just like how it’s done on the silicone buttons for remote controls.

Insert Coin (Cell) To Play LedCade

May 6, 2019 by Roger Cheng 3 Comments

In this era of 4K UHD game console graphics and controllers packed full of buttons, triggers, and joysticks, it’s good to occasionally take a step back from the leading edge. Take a breath and remind ourselves that we don’t always need all those pixels and buttons to have some fun. The LedCade is a μ (micro) arcade game cabinet built by [bobricius] for just this kind of minimalist gaming.

Using just three buttons for input and an 8×8 LED matrix for output, the LedCade can nevertheless play ten different games representing classic genres of retro arcade gaming. And in a brilliant implementation of classic hardware hacking humor, a player starts their game by inserting not a monetary coin but a CR2032 coin cell battery.

Behind the screen is a piezo speaker for appropriately vintage game sounds, and an ATmega328 with Arduino code orchestrating the fun. [bobricius] is well practiced at integrating all of these components as a result of developing an earlier project, the single board game console. This time around, the printed circuit board goes beyond being the backbone, the PCB sheet is broken apart and reformed as the enclosure. With classic arcade cabinet proportions, at a far smaller scale.

If single player minimalist gaming isn’t your thing, check out this head-to-head gaming action on 8×8 LED arrays. Or if you prefer your minimalist gaming hardware to be paper-thin, put all the parts on a flexible circuit as the Arduflexboy does.

Low Power Weather Station Blows The Competition Away

May 3, 2019 by Bryan Cockfield 10 Comments

Building a weather station isn’t too tall of an order for anyone getting into an electronics project. There are plenty of plans online, and you can even put your station on Weather Underground if it meets certain standards. These usually have access to a reliable source of power, though, and like any electronics project can get challenging quickly once it needs to work reliably in a remote location. The weather station from [Tegwyn☠Twmffat] has met this challenge though, and has been working reliably for three years now.

Getting that sort of reliability from any circuit that has to be powered by an unreliable source (solar, wind, etc.) and a battery is quite a challenge. Not only do you need to sort out the power management and make sure that you can get enough sun in the winter for your application, but you’ll need to do some extreme low power modifications to your circuitry as well. This weather station accomplishes all of that, helped by using LoRa for communication, and also comes complete with a separate hardware watchdog timer that can reboot the weather station if it loses power or hangs up for some reason.

If you’ve been looking for a weather station to build, this is a great place to start. [Tegwyn☠Twmffat] also goes through the assembly of the weather station, complete with a guy-wire-supported platform to mount it on. There are other weather stations out there too, if you need even more ideas about saving power in remote areas.