# Install Hardware (Optional)

> [!WARNING]
> **Warning:** The Google Assistant Library for Python is deprecated as of June 28th, 2019. Use the [Google Assistant Service](https://developers.google.com/assistant/sdk/guides/service/python) instead.

<br />

Now that you have the Assistant running on the device, it is time to extend it
with Device Actions. Device Actions allow you to control your device via voice.
For this example, you will be using a [Built-in Device Action](https://developers.google.com/assistant/sdk/device-actions-overview#built-in)
to turn a light on and off.

Follow these instructions to install an LED on the Raspberry Pi 3 Model B. In a
later step, you will modify the sample code to light the LED by voice command.

> [!NOTE]
> **Note:** Don't worry if you don't have an LED at the moment. You can still set up a Device Action and print some output to the terminal.

## Hardware requirements

Before you begin this example, you'll need the following components:

- A breadboard
- An LED
- A series resistor
- Two jumper wires, both with a male and female connector

The electrical resistance of the resistor should be tied to the specific LED.
To find the correct value, you can use an online calculator (or purchase a [kit](https://www.adafruit.com/product/3227)).

## Connect the components

> [!NOTE]
> **Note:** You may want to disconnect power to the Raspberry Pi to avoid short circuits.

1. Connect GPIO output pin [BCM25](https://pinout.xyz) to one side of a series resistor. Note that this is physical pin 22 on the Raspberry Pi 3.
2. Connect the other side of the resistor to the anode side (longer lead) of the LED.
3. Connect the cathode side (shorter lead) of the LED to ground.

![Wire an LED to the Raspberry Pi](https://developers.google.com/static/assistant/sdk/images/rpi3_schematics.png)

## Next step

[Register Traits](https://developers.google.com/assistant/sdk/guides/library/python/extend/register-device-traits)