I have a custom board using nRF52840. Some boards return success from sd_ble_gap_adv_start but no advertisement is seen in nRF Connect running on a Google Pixel 4 phone. Of the set of 4 boards I have to work with:
1 works fine
1 had a defective LF oscillator so failed earlier in the BLE startup.
2 boards return success when I try to start advertising, but no advertisements are seen.
On these 2 boards the firmware seems to run without hitting any assertions or otherwise crashing.
Since one board works, it seems that there must be some hardware difference causing the failure.
What could that cause be? I think if there was an LF oscillator problem I should not be able to enable the softdevice at all.
Is there any way to query the softdevice about its internal state to confirm that it thinks it is advertising and sending packets?
This failure happens both in our firmware (which uses FreeRTOS) and in the ble_peripheral/ble_app_blinky example (which I modified to work on our board).
Development environment is Segger Embedded Studio and nRF5 SDK v7.2.0
It seems hard to imagine this many failures either deep in the chip (dead radio?) or on the board (for the radio, just the antenna path and the 2 crystal oscillators should affect BLE operation, not that many components, visual inspection looks good. But then I was a bit surprised to have an LF osc failure, that's just the crystal and 2 load caps, not that much to go wrong.
Any ideas would be welcome, I am pretty much out of things to try.
