03-31-2019, 12:15 PM
While I appreciate the simplicity of effectively wiring the audio output to the audio input, I am afraid that this requires a calibration for each phone as I would expect that the output and input levels differ. So, for sensors that easily work across devices, digital communication (i.e. BLE) is preferable but requires more complex electronics, while this audio jack method is ingeniously simple to build for a single device.