The following are the pinouts for the Nikon hot shoe:
- Pin 1 — X (trigger)
- Pin 2 — Rdy (ready to fire)
- Pin 3 — Q (quench flash)
- Pin 4 — SP (Speedlight present
- mount — GND (Ground)
Note that different voltages are used on some of the pins to form a communication between camera and flash about abilities and state.
This information is not verified, nor it it certified by Nikon. Use at your own risk.