Sonoff 4CH Pro:

GPIO mapping is the same. All K5 switches should be set to "on", the S6 switch to 1. Then it works like the standard one.

I tried to find the GPIO IO-mapping for the 4CH Pro using HTTP commands. At GPIO-6 relay one got on but I could not switch it off again. Tried also to switch on GPIO 4 and 5. Then I could not connect to the GUI any more and now the 4CH Pro is in a boot-loop: INIT : Booting version: v2.0-20180120 INI...

Is there an IO-mapping for the Sonoff 4CH PRO available?

Thanks for help...