Ads by ArduinoGetStarted.com
ESP32 - Button - Relay
This tutorial instructs you how to use ESP32 to control LED based on the pressing state of button. In detail:
- If a button is being pressed, ESP32 activates a relay
- If a button is NOT being pressed, ESP32 deactivates a relay
We also have another tutorial: ESP32 - Button Toggles Relay, which toggle relay's state between ON and OFF when the button is pressed.
We can extend this tutorial to use button to control a led strip, siren, light bulb, or motor... by connnecting them to the relay.
Hardware Used In This Tutorial
Disclosure: some of these links are affiliate links. We may earn a commission on your purchase at no extra cost to you. We appreciate it.
Wiring Diagram between ESP32, Relay and Button
This image is created using Fritzing. Click to enlarge image
ESP32 Code
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-button-relay
*/
#define BUTTON_PIN 22 // ESP32 pin GIOP22 connected to button's pin
#define RELAY_PIN 27 // ESP32 pin GIOP27 connected to relay's pin
void setup() {
Serial.begin(9600); // initialize serial
pinMode(BUTTON_PIN, INPUT_PULLUP); // set ESP32 pin to input pull-up mode
pinMode(RELAY_PIN, OUTPUT); // set ESP32 pin to output mode
}
void loop() {
int buttonState = digitalRead(BUTTON_PIN); // read new state
if (buttonState == LOW) {
Serial.println("The button is being pressed");
digitalWrite(RELAY_PIN, HIGH); // turn on
}
else if (buttonState == HIGH) {
Serial.println("The button is unpressed");
digitalWrite(RELAY_PIN, LOW); // turn off
}
}
Quick Instructions
- If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
- Do the wiring as above image.
- Connect the ESP32 board to your PC via a micro USB cable
- Open Arduino IDE on your PC.
- Select the right ESP32 board (e.g. ESP32 Dev Module) and COM port.
- Copy the above code and paste it to Arduino IDE.
- Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
- Press and keep pressing the button several seconds
- See the change on the relay's state
Line-by-line Code Explanation
The above ESP32 code contains line-by-line explanation. Please read the comments in the code!
Video Tutorial
Making video is a time-consuming work. If the video tutorial is necessary for your learning, please let us know by subscribing to our YouTube channel , If the demand for video is high, we will make the video tutorial.
Language References
Learn More
Follow Us
