HOW to Program the Relay with ESP32

Overview

In our daily life, we usually use communication to drive electrical equipment, and sometimes we use switches to control electrical equipment. If the switch is connected directly to the ac circuit, leakage occurs and people are in danger. Therefore, from the perspective of safety, we specially designed this relay module with NO(normally open) end and NC(normally closed) end.

Working Principle

Relay is compatible with a variety of microcontroller control board, such as Arduino series microcontroller, which is a small current to control the operation of large current “automatic switch”.

Input Voltage：3.3V-5V

It can let the MCU control board drive 3A load, such as an LED lamp belt, a DC motor, a micro water pump and a solenoid valve pluggable interface design, which is easy to use.

Components Required

Connection Diagram

Test Code

//**********************************************************************************
/*
 * Description : Relay turn on and off.
 * Auther      : http//www.keyestudio.com
*/
#define  Relay  15 // defines digital 15
void setup()
{
pinMode(Relay, OUTPUT); // sets "Relay" to "output"
}
void loop()
{
digitalWrite(Relay, HIGH); // turns on the relay
delay(1000); //delays 1 seconds
digitalWrite(Relay, LOW); // turns off the relay
delay(1000); // delays 1 seconds
}
//**********************************************************************************

Test Result

Connect the wires according to the experimental wiring diagram, compile and upload the code to the ESP32. After uploading successfully，we will use a USB cable to power on. The relay will cycle on and off, on for 1 second, off for 1 second. At the same time, you can hear the sound of the relay on and off as well as see the change of the indicator light on the relay.