Ever wondered how to make your own 3D Mini Rain Car Wiper that automatically activates when it rains? 🌧️ This Arduino project tutorial will guide you step-by-step in building a miniature rain-sensing wiper system using an Arduino Uno, a rain sensor, and servo motors. Just like real car wipers, your Mini Rain Car Wiper will detect raindrops and sweep back and forth automatically.
What You’ll Learn
By building this project, you’ll:
- Understand how a rain sensor works and how it detects water droplets.
- Learn how to use Arduino Uno to control servos based on sensor input.
- Practice wiring and coding with digital pins, power supply, and servo motors.
- Discover how automation works in real life—just like a car’s automatic wiper system.
- Gain hands-on experience in combining sensors + actuators for simple robotics and DIY automation projects.
Why Build a 3D Mini Rain Car Wiper?
This project is more than just a fun DIY build—it’s an educational tool that combines learning and creativity. It offers practical learning by showing how sensors and automation work together in real-world applications, while also giving you the chance to develop hands-on skills in coding, wiring, and electronics assembly. With room for DIY creativity, you can customize the design, adjust the speed, or even add upgrades like potentiometer control or a manual/auto switch. It’s also student-friendly, making it perfect for hobbyists, makers, or students who want to explore robotics and automation through school projects. Most importantly, it provides a real-life simulation of how car wipers function, allowing you to replicate this system on a smaller, model-sized setup.
It’s similar to the Smart Laundry Bot project, but instead of moving a clothesline, the servos control wipers on a model windshield. The concept is the same: detect rain → trigger movement automatically.
What You’ll Need

Electronic Components
- Rain Sensor – detects water droplets on its surface
- Mini Servo – sweeps the wipers left and right
- Arduino Uno – the brain of the system
- 8 Slot Battery Holder – powers the servos and Arduino
- Battery AA – main power source
- USB Cable Type B – for uploading code to Arduino
- Jumper Wires – connections between components
Circuit Diagram:

To assemble the project:
1, Connect the rain sensor’s output pin to digital pin D2 on the Arduino.
2. Power the sensor from the Arduino’s 3.3V and GND pins.
3. Connect each servo to a separate digital pin:
- Servo 1 → D9
- Servo 2 → D10
- Power each servo with 5V and GND from Arduino.
4. Mount the servos so they act like wipers.
Pin Mapping:
- Rain Sensor: VCC → 3.3V | GND → GND | DO → D2
- Servo 1: VCC → 5V | GND → GND | Signal → D9
- Servo 2: VCC → 5V | GND → GND | Signal → D10
How it Works?
- The rain sensor detects water droplets.
- It sends a signal to the Arduino Uno.
- Arduino activates two servos, sweeping them like wipers.
- When no rain is detected, servos return to rest.
You can adjust in the code:
- Wiping Speed – change delay time.
- Wiping Range – modify servo angle values.
- Sensor Sensitivity – tune rain sensor threshold (light drizzle = intermittent, heavy rain = continuous).
Sample Code
#include <Servo.h>
Servo wiperLeft;
Servo wiperRight;
const int rainSensorPin = 2;
const int servo1Pin = 9;
const int servo2Pin = 10;
void setup() {
pinMode(rainSensorPin, INPUT);
wiperLeft.attach(servo1Pin);
wiperRight.attach(servo2Pin);
// Start at initial angle
wiperLeft.write(180);
wiperRight.write(180);
}
void loop() {
int rainDetected = digitalRead(rainSensorPin);
if (rainDetected == LOW) { // Rain detected
// Swipe like wipers
wiperLeft.write(90);
wiperRight.write(90);
delay(500);
wiperLeft.write(180);
wiperRight.write(180);
delay(500);
} else {
// Stop at resting position
wiperLeft.write(180);
wiperRight.write(180);
}
delay(100);
}
📹 Watch the Full Demo Video
Here’s the 3D Mini Rain Car Wiper.