In this blog, we will explore how a relay works, how to interface a single-channel relay with an Arduino Uno, and demonstrate a simple example of how to use the 5v relay module to control a lamp.

Connections are given Below : Arduino Relay Module +5V VCC GND GND PIN2 Signal Step 3 (Upload Sketch to Arduino) Download "sms_call_gate.ino" Sketch from the repository and Upload it to Arduino.

A 26.000MHz crystal is used in the ESP-01/ESP-01S module. In order to use the ESP-01 Wi-Fi relay module, a programmer/programming adapter is required to program the ESP-01 module (see below). Also it ...