Garmin Forerunner 945 can't read cycling power

[andrewNestorenko]

Hello,
first of all, thank you very much for the project! It's awesome!

I have an issue with Garmin Forerunner 945 which can't read cycling power even though it's reported.
Steps to reproduce:
Hardware: all listed in your blog post, but simplified a bit. I don't use level shifter and external power.
Software: main branch of the code with changed constant INVERT_PELOTON_SERIAL = true

1. Start the device and go to sim mode by AT command 'sim'
2. Make sure that you see data coming in console with power, speed, cadence and total output
3. Try to connect with Wahoo on mobile phone: reads all data correctly
4. Close Wahoo and try to connect FE 945

Watches sees only spd/cdc service which reports ony spd/cdc data without power.

I'm not sure if watches should see 2 sensors as there are 2 services installed.

I dig in a it and seems like all BLE sniffing software can correctly read and subscribe to CP service, they can read data.

Can you suggest any ways to debug what may be wrong, why watch doesn't want to read power data?

[ihaque]

It's hard to say exactly what could be going on. It does appear that the Forerunner 945 can use BT power sensors, so I assume it supports the CP service.

When I was implementing the CSC service and getting it to pair with my Venu, I noticed that the watch was far pickier about strict compliance to the spec than Wahoo was. In particular, I had to implement the SC Control Point characteristic to get the Venu to see CSC. Since the Venu doesn't support CP, I didn't look too hard there. It's possible that I missed a subtle detail of spec compliance. Maybe look in the CP Profile spec for language similar to what's quoted in the linked part of the post?