I am wondering if there is a way to set the BLE connection parameters in my custom firmware and also for the logbook service. As I would like to transfer data as fast as possible from the device to a mobile application.
From what I can see in the BLE spec, and from reading documentation the Connection interval, the number of packets per interval and the "data length extension" can be set to increase the transfer rate. But these cannot be set from the either the Android Device nor the iOS device. And the recommendation is to set it from the peripheral device
And from what I have read in the Movesense documentation I could not find any way of setting the preferred settings from trough the Movsense API.
Update: The BLE parameter customization is coming out in version 2.2
Original answer:
For now there is no way of setting the BLE connection parameters from the Movesense device. The default settings (connection interval 7.5ms-1000ms, MTU 158, DLE enabled) allow the phone to choose the best performing settings. I've typically seen connection interval of 45ms when connecting with Android phone that supports large MTU & DLE (BLE 4.2) which provides the maximum transfer rate possible (around 10-12kB/s).
We have planned to add a way to give more control to the BLE parameters as well as to optimize the power consumption in typical use cases (when this would be available for developers is not yet clear).
Full disclosure: I work for Movesense team