Bluetooth
The Raspberry Pi 3 sports Bluetooth connectivity which can be used to control the prototype.
Since version 0.9 of the SD-card image, a script which handles input from a Bluetooth controller (tested with the 8BitDo ZERO) is started on boot.
- Connect via SSH to the device or use the local terminal
- Start
bluetoothctl - Enable scanning with
scan on - Power the Bluetooth device
- Put it into pairing mode by pressing the select button
- Wait until it is detected (shows on terminal, may take quite some time)
- Pair the device
pair XX:XX:XX:XX:XX:XX(substituting the Xs by the MAC), wait for success message - Trust the device
trust XX:XX:XX:XX:XX:XX - Connect the device
connect XX:XX:XX:XX:XX:XX - If connecting is successful, the controller LED lights blue continuously.
- If this does not work power off and remove the paired device
remove XX:XX:XX:XX:XX:XXand start over - Leave the menu
exit
The next time, the controller should connect automatically. This is shown by rapid blue flashing on the controller LED.
This image shows the default controller configuration since version 0.9 of the SD-card image.
Amplification can be turned on (Up) and off (Down) (default on). In addition a (threshold simulating) noise can be turned on (Right) and off (Left) (default off). Three different gain tables for an assumed flat hearing loss of 45 dB which were generated with the openMHA GUI can be loaded with the buttons A (no gain), B (linear amplification by 40% of the hearing loss), X (compressive amplification according to Plack 2004 reduced by 10 dB). The Y button starts the recording of the environment for a duration of ten seconds. The feedback path can be re-estimated (RT button). The device can be powered off (Start) and openMHA can be muted (Select). The individualization of the gain table by measuring individual hearing thresholds is possible via the individualization menu (LT button).
The individualization is currently described in the tutorial.