DIY VT220 Keyboard

There’s always been interest in the computers of old, and people love collecting and restoring them. When [peterbjornx] got his hands on a DEC VT220 video terminal, it was in good shape – it needed a bit of cleaning, but it also needed a keyboard. [Peter] couldn’t afford to buy the keyboard, but the service manual for it was available, so he decided to convert a modern keyboard to work with his new terminal.

The original keyboard for the VT220 is the LK201. This keyboard communicates with the terminal using 8-N-1 (eight data bits, no parity, one stop bit) over RS232 at 4800 baud. This meant that it would be pretty simple to implement this on microcontroller in order to communicate with the terminal. [Peter] chose the Arduino Nano. However, the LK200 was more than just a keyboard for communicating with the terminal, it also housed a speaker and LEDs which the terminal used to communicate with the user. Rather than put these into the adapter unit, [Peter] decided to put these into the keyboard – a few holes and a bit of wiring, and they were in.

[Peter]’s write-up includes a description of some of the issues he encountered as well as a picture of the keyboard. He’s put the schematic online and the code up on GitHub. In case you were wondering, he used Vim on the VT220 to write his article. You could also use a Raspberry Pi to help out your dumb terminal, or just hook the terminal directly to your Linux box and go from there.

Dedicated Button for Toggling Screens

Anyone who regularly presents to an audience these days has known the pain of getting one’s laptop to work reliably with projection hardware. It’s all the more fraught with pain when you’re hopping around from venue to venue, trying desperately to get everything functioning on a tight schedule. [Seb] found that the magic keystrokes they used to deal with these issues no longer worked on the Macbook Pro Touchbar, and so a workaround was constructed in hardware.

The build itself is simple – an Adafruit Trinket serves as the brains, with a meaty 12mm tactile button used for input. The Trinket emulates a USB keyboard and sends the Cmd-F1 keypress to the computer when the button is pressed. The button’s even mounted in a tidy deadbugged fashion.

While it’s not at all complicated from a build standpoint, the key to this project is that it’s a great example of using the tools available to solve real-life problems. When you’re in a rush with 300 people waiting for your talk to start, the last thing you need to be worrying about is a configuration issue. [Seb] now has a big red button to mash to get out of trouble and get on with the job at hand. It does recall this much earlier hack for emulating a USB keyboard with an Arduino Uno or Mega. It’s a useful skill to have!


Unholy Mashup Of SpaceMouse And Sculpt Keyboard Is Rather Well Done

What do you do if you have a pair of input device peripherals for your computer, but they are from different manufacturers and thus not available as a single unit? If you are [Marco van Nieuwenhoven], you combine the two to make a mashup single peripheral.

[Marco]’s two peripherals were a 3Dconnexion SpaceMouse Wireless, and a Microsoft Sculpt Keyboard. His mashup isn’t featured here because it simply is a mashup, after all anyone with a hot glue gun could combine the two, instead he’s created a single peripheral that almost looks as though it could have been manufactured that way. It’s not complexity we’re looking at here, but elegance!

The Sculpt keyboard fortunately has a large palm rest in which the electronics and batteries sit, and he’s carefully measured the footprint of the top half of the SpaceMouse before hand cutting a very neat aperture to take it. The SpaceMouse PCB is attached below the aperture, and the bottom of the palm rest is attached with a little bit of padding to ensure a snug fit. The result: a combined input device to be proud of!

Of course, if this keyboard isn’t special enough for you, how about a typewriter?

Control The Volume

For anyone who has owned a boombox or an old(er) cassette player, the digital age volume controls feel incredibly awkward. Keep pressing buttons to get the volume just right can get tiresome real quick. The volume knob just makes sense and in a simple project, [Jeremy S Cook] brings us the Custom Computer Volume Control Knob.

The build employs an Adafruit Trinket board coupled with a rotary encoder and a push button as described by the designers themselves. We reached out to [Jeremy S Cook] to enquire about the build and it turns out his version uses an MDF enclosure as well as an MDF knob. A larger PCB has the encoder and button solder on with the Trinket board connecting to them via multi strand wires. An Acrylic sheet cut to the size serves as the top cover and completes the build.

The button serves as a play/pause button and can come in handy. Since the device enumerates as an HMI device, it should work with almost any OS. It could easily be extended to work with Android Tablets or even iPads. Check out the video below for a demonstration and if you like the idea of custom input devices, check out this DIY shortcut Keyboard. Continue reading “Control The Volume”

Hackaday Prize Entry: Dongle For A Headless Pi

Mass production means that there’s a lot of great hardware out there for dirt cheap. But it also means that the manufacturer isn’t going to spend years working on the firmware to squeeze every last feature out of it. Nope, that’s up to us.

[deqing] took a Bluetooth Low Energy / USB dongle and re-vamped the firmware to turn it into a remote keyboard and mouse, and then wrote a phone app to control it. The result? Plug the USB dongle in, and the computer thinks it sees a keyboard and mouse. Connect the phone via BLE, and you’re typing — even if you don’t have your trusty Model F by your side.

[Deqing] points out that ergonomics and latency will make you hate using this in the long term, but it’s just meant to work until you’ve got SSH up and running on that headless single-board Linux thing. If you’ve ever worked with the USB or BLE specifications, you can appreciate that there’s a bit of work behind the scenes in making everything plug and play, and the web-based interface is admirably slick.

Kudos, [deqing]!

DIY Shortcut Keyboard

Working with CAD programs involves focusing on the task at hand and keyboard shortcuts can be very handy. Most software packages allow the user to customize these shortcuts but eventually, certain complex key combination can become a distraction.

[awende] over at Sparkfun has created a Cherry MX Keyboard which incorporates all of the Autodesk Eagle Shortcuts to a single 4×4 matrix. The project exploits the Arduino Pro Mini’s ability to mimic an HID device over USB thereby enabling the DIY keyboard. Pushbuttons connected to the GPIOs are read by the Arduino and corresponding shortcut key presses are sent to the host machine.

Additional functionality is implemented using two rotary encoders and the Teensy encoder library. The first knob functions as a volume control with the push-button working as a mute button. The encoder is used to control the grid spacing and the embedded button is used to switch between imperial and metric units. The entire code, as well as the schematic, is available on GitHub for your hacking pleasure. It’s a polished project just ready for you to adapt.

The project can be extended to be used with other computer software such as Gimp and the keys may be replaced by capacitive touch sensors making it more sturdy. Bluetooth can be added to make things wireless and you can check out the Double Action Keyboard to extend functionality further. Continue reading “DIY Shortcut Keyboard”