- USB socket: When uploading a program to the Arduino it is done through a USB cable. The USB cable is connected to a computer and to the USB socket. The cable also provides power to the Arduino board.
- Reset button: When the reset button is pressed, the program uploaded to the board is restarted.
- On-board LED: This LED is connected to digital pin 13. You can turn the LED on or off by programming pin 13.
- Digital pins: You can connect digital inputs and outputs to these pins. There are 14 digital pins, numbered from 0 to 13.
- ON LED: This LED is turned on when the Arduino is supplied with power.
- Power socket: To provide the Arduino board with power you can connect a battery or adapter to the power socket. The recommended input voltage is 7-12V.
- TX and RX LED:s: The TX LED blinks when data is sent by the Arduino over the serial port. The RX LED blinks when the Arduino receives data over the serial port.
- Power and ground pins: The power pins are marked 3.3V and 5V. The ground pins are marked with GND.
- Analog pins: You can connect analog sensors to these pins. There are 6 analog pins numbered from A0 to A5.