A cunning little autofire circuit based on a 74HC04 hex inverter that uses the voltage supplied to a button for power. While it does have a miniscule "pause" in fire rate every second or so, it's excellent for use with most games and is incredibly cheap to produce.
Thanks to Yosai for drawing this
- Unplug the GND from a button on your panel
- Plug the spade connector from the circuit into the GND wire connector in your harness
- Connect either blue wire to the GND on the button
- (Optionally) connect the second blue wire to yet another button by disconnecting it's GND