ESP32 - Rain Sensor - Servo Motor

We are going to learn how to program ESP32 to control the servo motor if the rain is detected. In detail:

Hardware Used In This Tutorial

1×ESP-WROOM-32 Dev Module
1×USB Cable Type-C
1×Rain Sensor
1×Servo Motor
1×Jumper Wires
1×(Recommended) ESP32 Screw Terminal Adapter

Or you can buy the following sensor kits:

1×DIYables Sensor Kit (30 sensors/displays)
1×DIYables Sensor Kit (18 sensors/displays)
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.

Introduction to Servo Motor and Rain Sensor

Unfamiliar with servo motor and rain sensor, including their pinouts, functionality, and programming? Explore comprehensive tutorials on these topics below:

Wiring Diagram

ESP32 Rain Sensor Servo Motor Wiring Diagram

This image is created using Fritzing. Click to enlarge image

If you're unfamiliar with how to supply power to the ESP32 and other components, you can find guidance in the following tutorial: How to Power ESP32.

ESP32 Code - Rain Sensor Controls Servo Motor

/* * This ESP32 code is created by * * This ESP32 code is released in the public domain * * For more detail (instruction and wiring diagram), visit */ #include <Servo.h> #define RAIN_SENSOR_PIN 25 // The ESP32 pin GPIO25 connected to the sound sensor #define SERVO_PIN 26 // The ESP32 pin GPIO26 connected to the relay Servo servo; // create servo object to control a servo // variables will change: int angle = 0; // the current angle of servo motor int prev_rain_state; // the previous state of rain sensor int rain_state; // the current state of rain sensor void setup() { Serial.begin(9600); // initialize serial pinMode(RAIN_SENSOR_PIN, INPUT); // set ESP32 pin to input mode servo.attach(SERVO_PIN); // attaches the servo on pin 9 to the servo object servo.write(angle); rain_state = digitalRead(RAIN_SENSOR_PIN); } void loop() { prev_rain_state = rain_state; // save the last state rain_state = digitalRead(RAIN_SENSOR_PIN); // read new state if (rain_state == LOW && prev_rain_state == HIGH) { // pin state change: LOW -> HIGH Serial.println("Rain detected!"); servo.write(90); } else if (rain_state == HIGH && prev_rain_state == LOW) { // pin state change: HIGH -> LOW Serial.println("Rain stopped!"); servo.write(0); } }

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.
  • Click to the Libraries icon on the left bar of the Arduino IDE.
  • Type ServoESP32 on the search box, then look for the servo library by Jaroslav Paral. Please be aware that both version 1.1.1 and 1.1.0 are affected by bugs. Kindly choose a different version.
  • Click Install button to install servo motor library for ESP32.
ESP32 servo motor library
  • Copy the above code and open with Arduino IDE
  • Click Upload button on Arduino IDE to upload code to ESP32
  • Move your hand in front of sensor
  • See the change of servo motor

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.