# Setting up a board for RelayKeys

{% hint style="info" %}
If you have a pre-prepared Bluetooth stick (for example, from Ace Centre), you don't need to read this section. If you are buying your electronics to use, then read on. 
{% endhint %}

A wide range of Arduino boards supports HID (Human Interface Device). Often these are to emulate simple keypress' but to do more complex things like send one or modifier keys with a key - or to emulate holding a key down for a set period of time is either impossible or difficult to implement. Adafruit has developed the firmware on their Bluefruit nrf\* range of boards to emulate HID keyboards well using their AT Commands.

Currently, RelayKeys is designed to work with 

* the Adafruit Raytac nrf52840 dongle  (Buy from [the piHut](https://thepihut.com/products/nrf52840-usb-key-with-tinyuf2-bootloader-bluetooth-low-energy-mdbt50q-rx) or [Digikey](https://www.digikey.co.uk/en/products/detail/adafruit-industries-llc/5199/15189159?s=N4IgTCBcDaILIBEBCAVArABgIoFoBKAGiALoC%2BQA)). Note this is the cleanest looking solution and one of the cheapest. We have pre-prepared firmware for this for both receiving and sending. 

<figure><img src="/files/ujuUPDbyXZdtNTJXlK6R" alt="" width="188"><figcaption></figcaption></figure>

* [Adafruit Feather nRF52840 Express](https://www.adafruit.com/product/4062) (Buy in the [UK from Pimoroni](https://shop.pimoroni.com/products/adafruit-feather-nrf52840-express)). Note you can use this or the itsybitsy with a battery and have relaykeys work without connecting it directly to your AAC device.&#x20;

<figure><img src="/files/H74qepd5wbm8Yg65n4zF" alt="" width="160"><figcaption></figcaption></figure>

* or with the [Adafruit itsybitsy nrf52840 ](https://www.adafruit.com/product/4481)

<figure><img src="/files/kxfP52CzBYQaoUwGweGf" alt="" width="160"><figcaption></figcaption></figure>

* or with lesser support for the [The Adafruit - Bluefruit LE Friend - nRF51822 - v3.0](https://www.adafruit.com/product/2267) (Buy in the [UK from Pimoroni](https://shop.pimoroni.com/products/adafruit-bluefruit-le-friend-ble-4-0-nrf51822-v1-0#description)). *Although Note: We really aren't supporting the LE Friend much - we do hear it works, but dragons, beware!* See below for details on configuring these.

{% hint style="info" %}
If you are using a receiver dongle - follow the same guidance below but you will also need to copy over the firmware file for the dongle. Same procedure - different file name
{% endhint %}

Once you have your hardware you need to configure and set them up to work with relaykeys. Read on for how you do this for each device.&#x20;


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.acecentre.org.uk/products/relaykeys/installation/supported-boards.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.