nRF52832 occasionally doesn't start up with coin cell battery

RE: nRF52832 occasionally doesn't start up with coin cell battery

Vidar Berg — Mon, 20 May 2019 13:52:54 GMT

Hi,

[quote user="Francesco_M"]many thanks for your answer. It is not simple for us to reproduce the failed boot on nRF52832 because this happen tipical on 2-3 boards every 100, therefore to follow your suggested procedure attaching a debugger to a board we will require time[/quote]

Understand that it's difficult to reproduce. Considering that the battery becomes drained within a couple of days I think it's fair to assume that the device stays in this bad state. So when you reproduce this, try not to reset the device.

[quote user="Francesco_M"]In the meanwhile, please can you give us some hypothesis for the specified boot problem? Many thanks in advance.[/quote]

It's hard to say. But I think it could be caused by FW. I.e., the power-up sequence of the chip+external sensor causes an assert or hardfault that makes the app hang. Or have you enabled the watchdog timer which should prevent this?

RE: nRF52832 occasionally doesn't start up with coin cell battery

Francesco_M — Mon, 20 May 2019 13:08:44 GMT

Hi Vidar,

many thanks for your answer. It is not simple for us to reproduce the failed boot on nRF52832 because this happen tipical on 2-3 boards every 100, therefore to follow your suggested procedure attaching a debugger to a board we will require time. We will try to reproduce the problem on boot but we noted that it depends how we introduce coin battery inside battery holder. In the meanwhile, please can you give us some hypothesis for the specified boot problem? Many thanks in advance.

RE: nRF52832 occasionally doesn't start up with coin cell battery

Vidar Berg — Mon, 20 May 2019 12:30:31 GMT

Hi,

If possible, please attach a debugger to the device after it has failed to boot, then call "nrfjprog --readregs," then post the result here. The rise time you outlined should not be a problem.

Thanks,

Vidar