Universal mute toggle button: Arduino Uno turned into a USB-HID that sends the mute toggle keyboard shortcuts.

*Supported applications (MacOS only): Google Meets, Slack

Development

• Prepare for dfu programming: https://www.arduino.cc/en/Hacking/DFUProgramming8U2
  • Use real Arduino Uno
  • Install dfu programmer
  • Reset device
• Upload program that sends keypresses over serial: http://mitchtech.net/arduino-usb-hid-keyboard/
• Flash Arduino-keyboard-0.3.hex firmware (found online, included in this repo for convenience)
  • sudo dfu-programmer atmega16u2 erase
  • sudo dfu-programmer atmega16u2 flash Arduino-keyboard-0.3.hex
  • sudo dfu-programmer atmega16u2 reset
• To upload a new program, flash the original Arduino-usbserial-uno.hex firmware

References:

• https://arduino.stackexchange.com/questions/484/arduino-as-usb-hid
• http://mitchtech.net/arduino-usb-hid-keyboard/
• https://splatspace.org/2015/04/using-an-arduino-as-an-hid/
• https://www.arduino.cc/en/Hacking/DFUProgramming8U2
• https://gist.github.com/MightyPork/6da26e382a7ad91b5496ee55fdc73db2#file-usb_hid_keys-h