Arduino project · Water and plants · Easy
Rain Detector Alert
When rain falls on the plate, a servo closes the window and a buzzer warns you.
What you will learn
- How a rain sensor detects water
- How to move a window or cover with a servo
- How to combine alarm and action
How it works
Water on the plate lowers its resistance. Above 30 % wet the servo turns to close the window, the buzzer beeps and the yellow LED turns on. When the plate dries the window opens again.
Try this next
- Add a button to open the window by hand.
- Show the wetness on an LCD.
- Add a second plate for a washing line.
The simulator program and explanation on this page are original. The idea follows a classic Arduino project that students have built for years.
Parts: sensors and actuators (tap to show or hide)
Try the inputs (virtual sensors)
Pins (you can change them)
| Part | Arduino pin (change it here) | How to wire it |
|---|
Every wire, one by one
Red rail = 5 V from the Arduino 5V pin. Black rail = GND. The coloured wires carry signals. Match the wire colours on the drawing to this list.
| # | Colour | From (part and leg) | To |
|---|
Steps run from top to bottom, then start again. While the simulation runs, the active step is highlighted in green.
Quantities come from the parts you added. The store links open a search for that item on Robu.in, Amazon.in and ThinkRobotics, so you always see what is in stock today. Check the model, voltage and price before you order.
| # | Item | Qty | Search term | Buy / compare |
|---|
The PDF has the circuit sketch, pin table, every wire, sequence, full code, the parts list with store links, do’s and don’ts for each part, and the safety notes. The project file lets you come back and keep editing.
In the real world
A window that closes in the rain
Raise the rain slider. Rain falls outside, and the servo closes the window, so the room stays dry.
Tip: use the gold tab at the bottom of the circuit drawing to pull the real-world view up over the Arduino board. Your parts stay visible above it, so you can press a button and watch the real scene react.
- Rain sensor = rain on the glass
- Servo = the window closer