I use a Soartronic bluetooth module with my PowerFlarm Core (new Fusion version has bt build in). My Android pda is a Nokia 8 running LK8000 and this solution works well. Installation of the Soartronic (search on Facebook or go to www.soartronic.net) device with the PowerFlarm is very simple and already has the compatible RJ45 connector. These comments should also apply for XCSoar and TopHat if your Android device has bluetooth. The LXNAV S100 (which I have) can also drive your Android pda with it's built in bluetooth. Getting bi-directional exchange of data that is complete... was really challenging for the LK8000 developer in mid 2020. I worked intensely with him using my S100 and Android phone Nokia 8 with bluetooth. It now works very well using the Nano3 driver.