This project uses a Teensy LC to send keystrokes to a USB host. In my case, this is the Zwift cycling/running game.

Keep in mind I have no idea what I'm doing and I've just tweaked other's examples.

You'll have to set pin numbers and KEY_ commands accordingly. Add/remove what you need. Feel free to correct what I've got wrong.

For reference, this version is build based on a Teensy LC mounted on a breakout board a friend made, so the pins used make sense FOR ME. Feel free to alter the layout for what works for you.

Pin 13 is assigned to the onboard LED and I use that as a confirmation of keystrokes.

This was coded in VS Code using the PlatformIO. Carrying over to Arduino, I should think would be trivial, but DO NOTE, I beleive there you have to speficy this is a USB Keyboard in some pulldown. Here that is handled in the platformio.ini file. YMMV

Also note if programming the Teensy from Debian/Linux, if it doesn't program, look for an error message mentioning udev rules. Download the rules from: https://www.pjrc.com/teensy/00-teensy.rules

First big revision (ShiftKey Branch for now) is to use the "Enter" key as a modifier key. I think the logic is sound, but as yet untested. If another key is pressed while the Enter button is held, you get the alternate function. If the button is pressed and released with no intervening buttons, you get the standard Enter keystroke.

HARDWARE: With the Teensy LC, the hardware side is dead simple. Ground any pin (aside from 13) and Bob's your uncle. For my prototype, I had 5 small pushbuttons mounted up in an Altoid tin, Teensy insulated by tape, one ground wire to all the buttons, and then individual leads to each pin.

I 3D printed a case and added 5 more buttons. I need to fix up the design of the box a bit, but I hope to do that and get the stl here and/or a link to Thingiverse. The enclosure includes the male part of a Garmin Edge (and similar) GPS mount for easy handlebar mounting.

I'll try to remember to upload some pics.

If you're clueless like me, here's some stuff that got me going: https://wackyresearch.com/hacking-the-teensy-with-vs-code-and-platformio/ https://forum.pjrc.com/threads/53297-Could-anyone-show-me-the-Teensy-2-0-Keyboard-Code

Basic guide, but missing full working example useful to me: https://www.pjrc.com/teensy/td_keyboard.html

Not used, but another reference: https://www.pjrc.com/teensy/usb_keyboard.html

Notes from Zwift on available KB shortcuts: Navigating the UI You can use the following shortcuts when navigating the UI including the Home Screen and your in-game settings.

Enter Select. Esc Go back. ← Navigate left. ↑ Navigate up. → Navigate right. ↓ Navigate down.

Riding, Running, or Working Out in Zwift Check out the table below for available shortcuts while riding, running, working out, or participating in an event.

ESC Go back. A Access the PAIRED DEVICES screen. T Access your GARAGE. G Toggle Watt/HR Graphs When Riding M Send a group text. 1-9 Change your camera view. H Show or hide the display. F1-F8 Actions + Sound. PC: F10 OSX: Function + F10 Take a screenshot. OSX: Function + F9 Capture a video. Space Bar Activate a power-up. P Enter a Promo Code. Down Arrow Make a U-Turn. Up Arrow Display the Action Bar. Left and Right Arrows Initiate a turn at an intersection. E Open the TRAINING menu. Tab Skip a workout step. Page Up/Page Down Increase or decrease the FTP Bias.

HTH.