Disable the blue LED on RAK19003 and 19007

[ivmden]

Adding a flag to the build to disable the Blue LED on the RAK19007 and 19003 boards, and a call in SerialBLEInterface.cpp to turn the LED off.

Tested on a 19007 and 19003.

[liamcottle]

Howdy! Thanks for the contribution :)

I would probably opt to keep the LED enabled in default builds for now, as it's a very good indicator of when we have connection issues or the board locks up etc. We've had many support cases with connection issues and users have been able to tell us the LED is stuck on even when disconnected. It would be great to keep this for now.

Would you be willing to remove the -D DISABLE_BLUE_LED=1 from platformio.ini, or at least comment it out, and when you build your own firmware you can set this flag in the build script?

[liquidraver]

also remove this to keep it clean :)
// If we want to control BLE LED ourselves, uncomment this:
// Bluefruit.autoConnLed(false);

[ivmden]

I would probably opt to keep the LED enabled in default builds for now, as it's a very good indicator of when we have connection issues or the board locks up etc. We've had many support cases with connection issues and users have been able to tell us the LED is stuck on even when disconnected. It would be great to keep this for now.

(Please read this as conversational, not argumentative). You've also had multiple people asking about how to turn the LED off via discord. How can we strike a balance of keeping good debug tools and keeping energy usage reasonable/users happy? I tried getting it to turn off after the connection was well established but struggled with it.

Could a configuration: Off when connected, Flashing when trying to pair be a reasonable compromise?

also remove this to keep it clean :) // If we want to control BLE LED ourselves, uncomment this: // Bluefruit.autoConnLed(false);

Done.