app_error_fault_handler at 0x00024a44

[ConcourseOscar]

Good Day

We have an issue where our device will run normally in a full load condition for about 2 hours without issues but will suddenly go into the app_error_fault_handler. We had an infinite loop there allowing us to inspect it and we saw the handler is called from 0x00024a44 which is a Soft Device address. We tested this 3 times and it always failed at that exact address.

This is Soft Device version s140_nrf52_6.1.1_softdevice

We don't know how to debug this issue, any pointers for the nature of this error would be greatly appreciated. 

OP

[tesc]

Hi,

0x24a44 is the fault handler. The assert itself happened at the pc value of 96184, or in hexadecimal 0x177b8.

Are you by any chance using timeslots, or using interrupts conflicting with those reserved by the SoftDevice?

Regards,
Terje

[ConcourseOscar]

Hi Terje,

We have found that the MTU was set to 247 bytes. The documentation points out the CODED PHY mode must have a maximum MTU of 27 bytes. We ran a test with the MTU set to 27, sending data as normal through NUS and no error fault handler happened overnight. In that time, we would have expected a few resets otherwise. 

We'll continue to test and report back.

Thanks

OP