Arduino Project
Smart Rain Cover
Course Introduction
In this lesson, you’ll build a simple automatic rain cover using a raindrop sensor and a servo with the Arduino UNO R4.
When rain is detected, the sensor triggers the servo to rotate and open the cover. When the rain stops, the servo automatically returns to its original position, closing the cover.
Note
If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.
1.1 Install Arduino IDE(Important)
1.2 Introduction of Arduino IDE
Wiring

Common Connections:
Raindrop Detection Sensor Module
D0: Connect to 7 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s passive power bus.
Digital Servo Motor
Connect to breadboard’s positive power bus.
Connect to breadboard’s negative power bus.
Connect to 6 on the Arduino.
Writing the Code
Note
You can copy this code into the Arduino IDE.
Don’t forget to select the board(Arduino UNO R4 Minima) and the correct port before clicking the Upload button.
#include
/*
Raindrop Sensor + Servo Canopy
- If rain is detected (DO = LOW): servo moves to 90°
- If no rain (DO = HIGH): servo returns to 0°
*/
const int RAIN_DO_PIN = 7; // Raindrops sensor DO pin (LOW when rain detected)
const int SERVO_PIN = 6; // Servo signal pin
// Servo angles
const int SERVO_CLOSED_ANGLE = 0;
const int SERVO_OPEN_ANGLE = 90;
Servo canopyServo;
bool canopyOpened = false;
void setup() {
pinMode(RAIN_DO_PIN, INPUT);
canopyServo.attach(SERVO_PIN);
canopyServo.write(SERVO_CLOSED_ANGLE);
Serial.begin(9600);
Serial.println("Raindrop Servo Canopy Ready (DO LOW = Rain).");
}
void loop() {
int rainDO = digitalRead(RAIN_DO_PIN);
if (rainDO == LOW) {
// Rain detected -> open canopy
if (!canopyOpened) {
canopyServo.write(SERVO_OPEN_ANGLE);
canopyOpened = true;
}
} else {
// No rain -> close canopy
if (canopyOpened) {
canopyServo.write(SERVO_CLOSED_ANGLE);
canopyOpened = false;
}
}
delay(20);
}
