Below is the wiring for the Unitlite optical trigger
driving the MegaSquirt ECU. Add a 470 ohm 1 watt resistor to +12 as
shown. Alternately add the 470 ohm resistor internally to MegaSquirt
at +12V and to D5 where it connects to pin 24. Make
all the green jumper connections as shown.
You can test your input connection by monitoring IRQ-1
at R11. First set up MS to monitor IRQ with the center front panel LED.
Disconnect power to the coil. Put on the hand brake and the transmission
in neutral. Now turn the engine such that the crank pulley passes from
20º BTDC to TDC. The IRQ LED should go from On to OFF at ~10º
BTDC for most cars with distributor (but it may be from 5º to 15º,
usually this is called the static timing)
The MegaSquirt V3.0 will in turn then drive a single