If Bluefruit.begin fails, BLE OTA mode won't actually start and the board might require a reboot to reattempt.
Fixes:
- Bluefruit.begin returns false in NRF52Board.startOTAUpdate if OTA mode fails to start. User is notified of the fault through existing error message in CommonCLI and can reattempt "start ota" command.
Compile fails due to user_btn not declared in board target.
Fixes:
- Add MomentaryButton declaration for user_btn in variants/xiao_nrf52/target.cpp
- Add momentary button helper include in variants/xiao_nrf52/target.h
- Add extern linkage for MomentaryButton -> user_btn in variants/xiao_nrf52/target.h
Improvements:
- Add condition to only turn off display if on (avoids wedging the shutdown on some displays)
- Reset LoRa radio before calling radio_driver.powerOff() to ensure it is in a known good state (and will accept the command)
- Ensure SPI is started so LoRa radio commands can be sent (some shutdowns can happen before this)
- Add gate for P_LORA_NSS pin defined before writing to the pin
- Added build flag "SX126X_USE_REGULATOR_LDO" (set to 1 to enable) to use LDO for the SX1262 radio instead of DC-DC when the DCDC pin isn't wired up (e.g. t-echo lite)
- Added additional debug mode diagnostic messages during SX1262 init to better highlight faults
Added NRF52840 power management core functionality:
- Boot‑voltage lockout
- Initial support for shutdown/reset reason storage and capture (via RESETREAS/GPREGRET2)
- LPCOMP wake (for voltage-driven shutdowns)
- VBUS wake (for voltage-driven shutdowns)
- Per-board shutdown handler for board-specific tasks
- Exposed CLI queries for power‑management status in CommonCLI.cpp
- Added documentation in docs/nrf52_power_management.md.
- Enabled power management support in Xiao nRF52840, RAK4631, Heltec T114 boards