Part 14 of 15
Relay 5V
A switch your Arduino can flip
In your kit: 1×🔎 What is it?
A relay is a switch that your Arduino can turn on and off. You hear it "click". With a relay, your Arduino can turn another device on and off, for example a small fan or a lamp on a battery.
🔌 This is how you connect it
- S to a pin, for example D7
- + to 5V
- − to GND
- Connect the device you want to switch to COM and NO. NO means: normally off, on when the relay clicks.
Wiring diagram
| From | To |
|---|---|
Arduino UNO · GND |
Relay 5V · - |
Arduino UNO · 5V |
Relay 5V · + |
Arduino UNO · D7 |
Relay 5V · S |
✨ What can you do with it?
- A fan that turns on when it is warm
- A lamp on a timer
- A small pump for the plants
💡 Tip
Safety first: only use the relay with batteries or low voltage (up to 12V). Never with a wall socket (230V)!
Projects with this part
Codey Online is a product of OTRONIC