• Arduino based on the 32U4 chip (recommended: Arduino Micro Pro)
• USB to TTY
• HDMI to USB capture card

1. Flash the file key_passthrough/key_passthrough.ino onto the Arduino.
2. Unplug the Arduino.
3. Connect the following:

4. Plug the USB-TTY into the laptop
5. Plug the Arduino into the device to control

Prerequisit: python 3.8

pip install pygame==2.5.2

python3 passthrough.py [port]

The port argument is /dev/ttyUSB0 by default. test_ports.py can be used to help find the correct port.

Once the game window opens, select it and start typing!

Notes:

• You may need to run in sudo to access the ports. In which case make sure to sudo pip install pygame
• On Windows these are the COM ports
• If you are running in WSL, you need to activate your graphics and tell Windows to pass you the USB device: https://learn.microsoft.com/en-us/windows/wsl/connect-usb#attach-a-usb-device

• Connect the capture card to the device by HDMI and to the laptop by USB.
• Media -> Open Capture Device
• Select Show more options
• Caching: 0
• MLR: dshow:https://
• Edit Options: :dshow-vdev="USB Video" :dshow-adev= :dshow-aspect-ratio="16:9" :dshow-audio-samplerate=48000 :dshow-audio-channels=2 :live-caching=0 :dshow-fps=60 :dshow-size=1920x1080

Note: dshow-vdev may need to be adjusted, check the Video device name dropdown for exact name.

To open this automatically you can create a VLC shortcup with target: "C:\Program Files\VideoLAN\VLC\vlc.exe" dshow:https:// :dshow-vdev="USB Video" :dshow-adev= :dshow-aspect-ratio="16:9" :dshow-audio-samplerate=48000 :dshow-audio-channels=2 :live-caching=0 :dshow-fps=60 :dshow-size=1920x1080 (example in Capture.lnk)

Original keyboard passthrough and inspiration: https://euer.krebsco.de/a-software-kvm-switch.html