Well here’s my dilemma. I’ve got these tits mil-spec switches from eBay, one of which i want to use for my flap switch. The flap switch needs to send UP, HALF and FULL signals to the PlasmaV2, so I need an on-on-on toggle, but the switches are only on-off-on. Something has to give. So, I figured with a little bit of electronicky goodness, I could fake the centre position to bridge a signal to ground on the Plasma. Here’s how I did it (in theory – it’s only built in the circuit simulator so far):
The DP3T switch is not represented in my circuit simulator, so I’ve used 2 DPDT. The switches in the diagram can either be left on right off, both off, or left off right on to simulate the 3 possible positions of the DP3T toggle. The 4 rails at the top are the 3 +ve and 1 GND rails from the PlasmaV2. When a +ve rail is shorted to ground, the Plasma picks it up as a specific button press. One each for FLAP UP, HALF and FULL. The 5V and 0V rails on the left are a standard 5V supply from a PC PSU molex – they are used to power the relay in NC mode, switched through the other half of the DP3T switch.
In the first pic you can see the left half of the 2xDPDT (representing up on the DP3T) is closed whilst the right half is open. The first PlasmaV2 signal wire is shorted to ground, sending FLAP UP to the PC via the PlasmaV2. Crucially, the other pole powers the relay, which is Normally Closed – opening the circuit and preventing the second signal wire from getting a current.
In this pic you can see the “virtual” DP3T in the centre position, which with a standard DP3T would be off. However, as neither “on” input is powering the relay, and the relay is Normally Closed, the circuit for the second PlasmaV2 input is complete and the FLAP HALF signal is sent.
This is similar to the first case – the relay is powered so signal wire 2 has no current and signal wire 3 is shorted to the PlasmaV2 ground to send “FLAP FULL”.
Easy peasy japanesey!