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 or Digikey). Note this is the cleanest looking solution and one of the cheapest. We have pre-prepared firmware for this for both receiving and sending.

• Adafruit Feather nRF52840 Express (Buy in the UK from Pimoroni). Note you can use this or the itsybitsy with a battery and have relaykeys work without connecting it directly to your AAC device.

• or with the Adafruit itsybitsy nrf52840

• or with lesser support for the The Adafruit - Bluefruit LE Friend - nRF51822 - v3.0 (Buy in the UK from Pimoroni). 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.

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.

Either use the drag and drop UF2 method or more steps involved - Arduino uploading method. For the UF2 method

• Download the UF2 file for the itsybitsy board in the current release

• Double click that reset button. You will then get a USB drive on your computer. Drag and drop the UF2 file to the root of that drive.

• It SHOULD disconnect from your pC if successful – but as I say the loghts should change colour to Green

• More details see the steps

Or the Arduino uploading method.

• Check the setup of your (remember we're using the nRF52840 board!)

• Upload the to your feather.

• Run the server side code

• Done!

Plug-in Your RelayKeys stick & pair with a computer (Wired mode)

1. Make sure the Micro-USB connector is attached to the stick and then attach the female end of the USB lead into your computer

2. You should see your stick light a solid blue ("Paired") or flashing blue ("Un-paired")

If "Flashing". This means you have yet to pair the RelayKeys device with another computer.

Put RelayKeys into a pairing mode

You can do this in three different ways:

• Send a command using the "relaykeys-QT.exe" app and press "Add a device" in the toolbar - or -

• Run "relaykeys-cli.exe ble_cmd:devadd" - or -

• Press the Button on the RelayKeys hardware. It will now flash yellow

• Next pair your device with RelayKeys.

Pair with a Windows Computer

So to connect to Another Windows computer, go to Settings, Bluetooth, "Add a device", and connect to "AceRK"

Pair with an iOS device

Pair with a Mac

To connect to a mac, Open up "System Preferences", Bluetooth and add "AceRK"

Download the installer from here. When downloaded 'Run' the program

Step through the installation procedure. Select 'Normal install' and let the RelayKeys setup software do its thing to install the software in the correct place (By default: C:\Program Files (x86)\Ace Centre\RelayKeys).

• Install the CP2104 Driver

• Update it to 0.8.1. Easiest way to do this is to connect to using the Bluefruit app - it will auto-update it if required.

• Plug it in

• Set the switch on the device to CMD mode

• Open up a serial terminal and connect to the device (See here for exact settings for your Operating System)

• Turn on HID Mode. More info here. To be precise - enter this into your serial terminal

  Copy

    AT+BLEHIDEN=1
  
    ATZ 

(You should see 'OK' after each entry)

• Next change the default speed. i.e. enter this in your serial terminal:

  Copy

    AT+BAUDRATE=115200

• Next put the device into DATA mode (slide the switch).

• Finally - update the relaykeys.cfg file with

  Copy

    baud = 115200
    

(Or whatever speed you so wish)

Either use the drag and drop UF2 method or more steps involved - Arduino uploading method. For the UF2 method

• Download the UF2 file for the raytac dongle in the_ __

• Press and hold thr reset button as you plug it into the computer. You will then get a USB drive on your computer. Drag and drop the UF2 file to the root of that drive.

Or the Arduino uploading method.

• Run the server side code

• Done!

1. Open up something on the second computer that you can enter text into. E.g. Notes on the iPad, Notepad on Windows or Notes on a mac

2. On your server computer (the one with RelayKeys attached) run "RelayKeys" (search for it in your Windows search bar). Alternatively find it in C:\Program Files(x86)\Ace Centre\RelayKeys\relaykeys-qt.exe

3. With the window having focus - type into it. You should see the keystrokes appear on the second computer

Using it with your AAC software

You can get going by using one of these example files that work with your AAC Software:

• The Grid 3

• MindExpress

• Tobii Communicator

• Tobii Dynavox Snap

When you are ready, have a read of how to integrate the features you need.

👍 You've successfully installed and setup RelayKeys! Now you may want to use the CLI or QT program. Read on to find out how these work.

😞 Got a problem? Dang! See our troubleshooting guide.

Plug in your receiving dongle to a device. Your device will see this as a keyboard attached. If you are asked to press some keys for the device to understand it, just close this window for now.

On the sending side, it will pair by default with the receiver. You don't need to do a thing. However, if you have gone and paired with any other devices, you may find this not work. You will need to remove any paired devices and try again.

There are 3 broad configurations for RelayKeys

• Wired Mode. This is where one Bluetooth dongle is in the Sending device

• Wireless Mode. This is where a Bluetooth dongle plugged into a power outlet or a battery sits away from the Sending device. This might be useful for devices where you cannot plug anything into the sending device

• Wired + Receiving Dongle. A receiving dongle sits in the receiving device. This is useful where "pairing" is unreliable on the recieving device or there is no Bluetooth stack on the receiving computer.

You need to decide what is best for you.

The easiest way to get up-and-running is with the Windows Installer, which includes the RelayKeys-CLI, and the RelayKeys-Desktop software. Read on to see how to install and setup.

A quick reminder of how this works

So RelayKeys consists of a hardware solution that talks Bluetooth HID to secondary devices - anything that can pair with bluetooth and understand a keyboard works, and some software on the 'server' device; i.e. the device sending the key/mouse movements. So for our installation we really focus on the 'server' since the recieving device needs no additional hardware or software.

Requirements

RelayKeys is designed to work on Windows, Linux, and Mac Operating Systems. We have built a Windows installer that makes the process easier on that platform. For Mac & Linux, you will need to build the app from the source.

• Windows 7-10

• A USB Port

• Ability to Install the software as Administrator

• A second device to connect to Could be a Windows computer, a Mac, an iPad etc

and most importantly:

• A supported piece of RelayKeys-ready hardware

  • Right now: this is designed to work with the Adafruit nrf52840 express, Adafruit nrf52840 Itsybitsy or Raytac nrf52840 dongle Others will be added to the list as this is developed.

  • Note: if you wish to use a dongle to receive - instead of relying on a device's internal Bluetooth and pairing etc - you will need a second board.

Either use the drag and drop UF2 method or more steps involved - Arduino uploading method. For the UF2 method

• Download the UF2 file for the feather nrf52840 express board in the current release__

• Double click that reset button. You will then get a USB drive on your computer. Drag and drop the UF2 file to the root of that drive.

• It SHOULD disconnect from your Computer if successful and the light should change colour to Green

• More details see the steps here

Or the Arduino uploading method.

• Check the setup of your Arduino IDE (remember we're using the nRF52840 board!)

• Upload the sketch to your feather.

• Run the server side code

• Done!

Note that this mode is useful on devices where you can't plug anything into your device. The setup can feel strange - what we need to do is tell your relaykeys hardware the device to connect to.

1. Plug in device and follow instructions as above

2. Pair the main AAC/Host device with it. So pair the computer you have attached it to with RelayKeys hardware. This can feel a bit strange - you are connecting the hardware to the same machine you are on. See here for how to put it into pairing mode.

3. Disconnect the relaykeys hardware. In your bluetooth settings you actually need to click on the item and "Remove" device. (NB: If you cant do this it might be because you need to be an admin. The trick is open the Control Panel -> Devices & Printers -> Relaykeys -> Right click, Remove and you will be asked for an Admin password)

4. Plug relaykeys into a power source - away from the computer. Your RelayKeys may have a battery or you might need to plug into a wall USB power source.

5. Double press the User switch It should now shine a nice blue colour!

6. Run RelayKeysd with --ble_mode See here for more details