HW-622 ESP8266 Relay Board
HW-622 ESP8266

Available from:

Install method:
USB to Serial

GPIO #Component
GPIO00 None
GPIO01 None
GPIO02 LedLink
GPIO03 None
GPIO04 Relay1
GPIO05 Button1
GPIO09 None
GPIO10 None
GPIO12 None
GPIO13 None
GPIO14 None
GPIO15 None
GPIO16 None
Template (old version)

DYI ESP8266 relay with external optoisolated button. Requires an external power supply. The input from the switch is opto-isolated so the 5V can be used directly to supply the switch. Unfortunately, it appears that many cevices do not have the 0V connected on the input. A connection needs to be made from the 0V on the supply to the 0V on the signal input.