🌧️ Raindrop Detection Sensor

📌 Description

The raindrop detection sensor is designed to sense water droplets on its surface. It works by detecting changes in conductivity: when raindrops fall on the sensor’s board, the circuit closes and sends a signal to the microcontroller.

🎯 Use

In our projects, the raindrop sensor is used to:

• Detect rain for weather monitoring.
• Trigger protective actions (like closing a window or covering electronics).
• Help robots react to environmental conditions outdoors.

👉 Think of the raindrop sensor as the robot’s rain detector — it knows when it’s wet outside.

Module parameters

Pin name	Description
G	GND (Power Input Negative)
V	VCC (Power Input Cathode)
S	Digital signal pins
A	Analog signal pins

• Supply voltage: 3.3V/5V
• Connection: 2.54mm pin header
• Installation method: double screw fixing

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🖥️ Code Explanation

import machine

pin25 = machine.Pin(25, machine.Pin.IN)    # Sensor input
pin26 = machine.Pin(26, machine.Pin.OUT)   # LED output

while True:
    if pin25.value() == 1:                 # If no rain detected
        pin26.value(0)                     # LED OFF
    else:                                  # If rain detected
        pin26.value(1)                     # LED ON

Step by Step

1. pin25 = machine.Pin(25, machine.Pin.IN) → Reads the raindrop sensor’s digital signal.
2. pin26 = machine.Pin(26, machine.Pin.OUT) → Controls the LED (output).
3. while True: → Loop that repeats forever.
4. if pin25.value() == 1: → Checks if the sensor is dry (no rain).
5. pin26.value(0) → LED stays off when no rain is detected.
6. else: → If raindrops are detected…
7. pin26.value(1) → LED turns on to indicate rain.

👉 Together, this program makes the LED light up when rain is detected.

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✅ Conclusion of the Test

• If the LED stays off when the sensor is dry, and turns on when raindrops touch the sensor, the program is working correctly.
• This test shows how the robot can sense rain and react with an output (LED).
• Later, the sensor could be used to trigger alarms, activate windshield wipers, or protect outdoor robots from water damage.