A small keyfob to wake up a sleeping laptop - useful on external monitor setups where the laptop lid is closed and you need to wake up the laptop without opening the lid.

It sends a single character (currently [ as it's broken on my keyboard) and waits 1 second until another event can be triggered.

The device is a "Rubber Ducky" with a male USB A and nothing else. I'm abusing the analog input to go low when touched and be kind high when not (I'm using A0). It's not a perfect mechanism, but it's a nice hack. You don't have to solder anything and you can touch it from both sides (heh - wink) in case of a reversed USB port.

I won't go into BOM details as you just need this. It's an "Arduino Leonardo" - aka an ATMega32U4 on a breakout board.

I'm sure this will work on DigiSpark-like boards, you just have to change the keyboard handling function but I couldn't get my DigiSpark to work (they're ATTiny85 with a software USB implementation).

pio run --target=upload to flash it on your board and you're set!

NOTE: The laptop should power the USB device while asleep or you have to use an externaly powered USB home for this setup to work

Have fun!