This small Arduino project shall demonstrate how to connect Yi cameras which support Bluetooth remote capability to a nRF52. The nRF52 is a Bluetooth 5 chip which supports multiple connections at a time and thus supports remotly controlling multiple Yi cameras at once.
You will need to order one Bluefruit Feather nRF52832 board at Adafruit and install all the necessary Arduino Board definitions.
Once installed clone this project into your Arduino project folder and open the *.ino file with the Arduino IDE. Be sure to have the IDE properly setup. Take special care to use a bootloader newer than 5.0.0 since only those support multiple connections.
Then simply upload the sketch and switch your Yi camera in normal pairing mode. You should see it connecting. Once connected and paired ground either pin 11 for SHUTTER or pin 7 for MODE.
The code is quiet hacky since it messes a bit with the Adafruit HID example. For all who want to know more deeply whats happening:
The Yi camera scans for devices with the appropriate MAC adress and name, then connects them and enables notifications for one specific characteristic (HID Report Ref 3).
Then it basically waits until one notification is sent and triggers the corresponding action.
So basically the Yi remote acts a standard HID keyboard which presses either VOLUME_UP for MODE or VOLUME_DOWN for SHUTTER.
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