Digispark morse key interface
This is a very simple method of using an an inexpensive Digispark development board to work as an interface for morse key/paddle for Ham Radio Solutions's vband (Virtual CW Band).
Setting up the USB drivers was the most difficult part for me, but this video helped me get it sorted out.
To connect your paddle to the digispark, you can use a 3-pole (TRS) 3.5mm pigtail plug, soldering the tip (left paddle) to P0, the ring (right paddle) to P2, and the sleeve to ground. Note that without an external pull-up resitor P1 will always read LOW, but P0 and P2 work just fine with no additional resistors. Pins 3 and 4 can't be used while the board is connected via USB.
Install the sketch to the board. Now your key will look like a usb keyboard that just presses left and right Ctrl keys with your paddles. It should also work fine with a straight key.
Some inspiration was taken from https://github.com/kevintechie/CWKeyboard, but this is a much simpler set-up.