The [Arduino](https://www.arduino.cc/) device family are microcontroller boards that are often based on the ATmega328 chip. They come with digital input/output pins (some can be used as PWM outputs), analog inputs, and a USB connection. The equipment depends on the [type](https://www.arduino.cc/en/Main/Products) of board. The most common ones are the Arduino Uno and the Arduino Leonardo with 14 digital input/output pins and 6 analog input pins.
There are a lot of extensions (so called [shields](https://www.arduino.cc/en/Main/ArduinoShields)) available. Those shields can be plugged-in into the existing connectors and stacked on top of each other. This makes it possible to expand the capabilities of the Arduino boards.
## Basic Configuration
The arduino component is designed to let you use a directly attached board to your Home Assistant host over USB.
You need to have the [Firmata firmware](https://github.com/firmata/) on your board. Please upload the `StandardFirmata` sketch to your board, please refer to the [Arduino documentation](https://www.arduino.cc/en/Main/Howto) for further information.
To integrate an Arduino boards with Home Assistant, add the following section to your `configuration.yaml` file:
```yaml
# Example configuration.yaml entry
arduino:
port: /dev/ttyACM0
```
The port where is your board connected to your Home Assistant host. If you are using an original Arduino the port will be named `ttyACM*`. The exact
number can be determined with `ls /dev/ttyACM*`.
```bash
ls /dev/ttyACM*
```
If that is not working, check your `dmesg` or `journalctl -f` output. Keep in mind that Arduino clones are often using a different name for the port (e.g. `/dev/ttyUSB*`).
A word of caution: The Arduino boards are not storing states. This means that with every initialization the pins are set to off/low.
## Switch Configuration Support for switching pins is limited to high/on and low/off of the digital pins. PWM (pin 3,5,6,9,10, and 11 on a Arduino Uno) is not supported yet. To enable the Arduino switch pins with Home Assistant, add the following section to your `configuration.yaml` file: ```yaml # Example configuration.yaml entry switch: platform: arduino pins: 11: name: Fan Office type: digital 12: name: Light Desk type: digital ``` The digital pins are numbered from 0 to 13. The available pins are 2 till 13. For testing purposes you can use pin 13 because with that pin you can control the internal LED. The name field of the pins array will be used in the frontend. ## Sensor Configuration The sensor platform allow you to get an numerical values from an analog input pin. Usually between 0 and 1024. To enable an Arduino sensor with Home Assistant, add the following section to your `configuration.yaml` file: ```yaml # Example configuration.yaml entry sensor: platform: arduino pins: 1: name: Door switch type: analog 0: name: Brightness type: analog ``` The 6 analog pins are numbered from A0 to A5. The name field of the pins array will be used in the frontend.