ESP3D/wiki/Sonoff.md

Wiring Sonoff modules

Relay is connected by GPIO12, it can be handled using ESP201 command:

*Get/Set pin value
[ESP201]P<pin> V<value> [PULLUP=YES RAW=YES]
if no V<value> get P<pin> value
if V<value> 0/1 set INPUT_PULLUP value, but for GPIO16 INPUT_PULLDOWN_16
GPIO1 and GPIO3 cannot be used as they are used for serial
if PULLUP=YES set input pull up, if not set input
if RAW=YES do not set pinmode just read value

So [ESP201]P12 V0 should be off and [ESP201]P12 V1 should be on