Introduction

The ESP can control a relay board using one of it's GPIO pins. All relay boards that work with Arduino should also work with the ESP module.

Connect the relay boardj to one of the GPIO pins on the ESP module. In case of ESP-01, we will use GPIO-2

Hardware

Most of the relay boards expect a 5V ttl signal like many arduino boards provide on their output pins. But 3V3 logic should also work.

We can control the relay board with two simple http url commands:

http://<ESP IP address>/control?cmd=GPIO,<pin>,0

http://<ESP IP address>/control?cmd=GPIO,<pin>,1

Domoticz example:

Syntax: WiredOut 1,On/Off