Architecture of RelayKeys

RelayKeys Sketch

RelayKeys is a mixture of a Open Hardware board that communicates in Bluetooth LE and acts as a BLE HID device (i.e. a keyboard/mouse) which can emulate all keyboard keys and their modifiers as well as mouse movements. (4). This is controlled by a serial connection from a device - either wired (i.e. as a USB dongle) or wireless (i.e. as a BLE Serial device). We have developed RPC server (2) for a desktop computer which simplifies software connecting to the serial bus and allows us to create a simpler way of sending commands to the device than AT commands. This is done either directly via the RPC Server (Daemon) or via a Command Line Interface (CLI). **** As a demonstration we also have a small graphical interface application (RK-Desktop also referred to as the Relaykeys-QT application) (1).

If you make software and want to benefit from the features of RelayKeys you can either write commands to the RPC server (2), or via our CLI (1) or if you wish direct to the serial interface (6). This can be wired serial or wireless if you put the device into wireless mode (5). Even if you wish to ignore our hardware we do ask Assistive Technology developers to consider copying the command structure at either one of these levels to allow for open development.

The Arduino based board is currently a Adafruit nrf52840 express or Adafruit nrf52840 itsybitsy.

Anatomy of the files

• arduino/ - firmware for the arduino board

• docs/ - VuePress docs for http://acecentre.github.io/relayKeys/. Build Script is docs-deploy.sh

• resources/ - Helper files for development (e.g. demoSerial.py which pretends to be an arduino board connected, viewComPorts which outputs the connected com ports), AAC software pagesets and all-keys.txt which is a output of all the keys supported by RelayKeys. Also note the development files - relaykeys-pygame and relaykeys.py - which are stripped down versions of the whole project. Useful for debugging and testing things without the daemon server. Just move relaykeys.py into the root directory to get it to work.

• blehid.py - Library/Import file used by relaykeysd. Includes the function that writes the AT command to the serial port, init the serial port, and sends keyboard/mouse codes.

• build.py, buildinstaller.nsi - Build files to turn this project into a installer. Run python build.py to trigger the build.

• docs-deploy.sh - deploys the documentation to the github pages site.

• relaykeys-cli.py - This is the command line interface version of relaykeys. Conencts to the daemon server.

• relaykeys-example.cfg - The default config file. Note this gets copied on install to the right location and is used as the standard config. Note commented out baud and dev lines. Dev fixes the COM port if the com port finding code doesn't work

• relaykeys-qt.py - The GUI version of our relakeys testing app.

• relaykeys.spec.ini - Used for the NSIS build (i.e. buildinstaller.nsi)

• relaykeysclient.py - The main library file used by -cli and -qt versions. Connects to the server.

• relaykeysd-service-restart.bat, relaykeysd-service.py - The Windows service applcation

• relaykeysd.py - The daemon. This is what is run in the background - and controlled by the service. If you want to test RelayKeys - run this file first - and leave it running. e.g. python relakyeysd.py &&. Note the command line flags in the header.

Steps to run RelayKeys (non-installer method)

Prerequisites

• Install Python 3
• Have access to a nrf52840 arduino board. e.g. the Adafruit nrf52840 express

1. Grab a nrf52840 board and load the arduino code onto it. Plug it in a usb slot on your computer

2. Check your arduino is working as expected. Find and make a note of the COM port it is (found in the device manager)
3. Download the code to a sensible location - e.g. git clone https://github.com/AceCentre/RelayKeys.git

4. Copy the relaykeys-example.cfg file e.g. copy relaykeys-example.cfg relaykeys.cfg

5. Install requirements e.g. pip install -r requirements.txt

6. Run the Daemon code. python relaykeysd.py

7. Pair your relaykeys arduino with a PC/Mac/iOS/Android device and open a text file

8. Test it out with the cli file e.g. python relaykeys-cli.py type:Hello

You should, if everything is working as expected, see it type on the second device. If not have a look at the log files.

One problem may be that the daemon cant find the COM port. You can fix this by fixing the com port you found in step 2 and putting it in the config file. e.g. add dev=COM6 if the com port is 6. More information can be found here