nRF51822 QFAA resets when connecting to it

RE: nRF51822 QFAA resets when connecting to it

Nguyen Hoan Hoang — Sun, 07 Jan 2018 20:08:44 GMT

First thing to check, your chip (16KB) has less ram than the DK (32KB). Have you modify the ld script for the ram size of your chip ? Second a reset could be caused by a SDK returning an error code. Breakpoint in the error handler and back track stack to see where it happened.

RE: nRF51822 QFAA resets when connecting to it

MartinBL — Fri, 05 Jan 2018 12:54:30 GMT

I suppose a sniffer trace could also be useful. You can use our sniffer solution and your nRF51 DK to sniff the packets from your custom board.

RE: nRF51822 QFAA resets when connecting to it

endnode — Fri, 05 Jan 2018 08:58:42 GMT

HW problems like missing passive components or antenna stage problems should be the last. If you say what Soft Device you use we could have a look if chip version without AN is the problem but again it's unlikely that you would pass all the initialization up to the GAP Peripheral advertising and link establishment. Memory mapping again should cause failure earlier but who knows. In the end you will nee to debug the FW, guessing over the internet does work only in small percentage of cases;)

RE: nRF51822 QFAA resets when connecting to it

endnode — Fri, 05 Jan 2018 08:42:52 GMT

Btw. if the FW works well on Dev Kit then you should check LF and HF clock sources because these are typically the only differences which matter for FWs which are using Nordic Soft Device. They typically fail during SD init not later but it can happen. If this is fine then make sure you compile for good target (ROM = flash and RAM memory limits). FW compiled for smaller chip version should still work on bigger variant (so on DK it should be always OK while on some other board with smaller chip not). Also check that chip on your custom board is Rev3! That's coded on letters after QFAA/QFAC code. If you have Rev2 it still can work but if you have Rev1 then many BLE FW examples with newer Soft Device won't work.

RE: nRF51822 QFAA resets when connecting to it

PabloGC — Fri, 05 Jan 2018 08:39:11 GMT

My main question is what causes this if the same FW works perfectly in the Nordic Dev Kit:

Is it missing a decoupling capacitor?
Is it because the nRF 51822 QFAA doesn't have enough memory space (mapped from the FW) to manage BLE connections?
Is it because of the Antenna's design?
Is it because nRF 51822 QFAA is missing ANT?

RE: nRF51822 QFAA resets when connecting to it

endnode — Fri, 05 Jan 2018 08:39:08 GMT

Well black box or not, you have it in the source code, you have compiled it so I'm afraid you should debug;) LED is fine for the beginning but as this is 100% reproducible and in software then logical next step is to enable UART logging, attaching some UART serial to USB (virtual COM port) cable and looking into the log on PC (in some terminal like PuTTY) where is the assert. If not visible then put some more logging (just keep it short not to disturb the operation with too much processing) and dig into it until you will find the place. There is big chance that once you will see it you will understand the problem straight ahead. If not then there is good chance that someone here will help you with analysis. I don't think anyone here would (and should) spend time on debugging your FW...

RE: nRF51822 QFAA resets when connecting to it

PabloGC — Fri, 05 Jan 2018 08:34:02 GMT

Your description is little confusing: is your "custom" board running GAP Peripheral role and you connect to it from your phone with nRF Connect app?

- Yes, I connect with my phone to my custom board;

Also what FWs you run on the devices?

   - A modified version of BLE_APP_HRS. The FW works properly when upload to Nordic Dev Kit (this means that my phone can connect and receive correct data from NDK);

Like having UART logging and see what SD call returns unexpected error code, if it is asserted in your FW and you reset the board from FW or is it some total hard fault going from Soft Device?

  - I'm debugging with a LED. The reset occurs whenever the phone connects to the board. This part of the code should be a black box provided by the examples from Nordic (didn't touch anything from here or the handler that manages the connection protocols);

RE: nRF51822 QFAA resets when connecting to it

endnode — Fri, 05 Jan 2018 07:32:34 GMT

Hi Pablo,

Your description is little confusing: is your "custom" board running GAP Peripheral role and you connect to it from your phone with nRF Connect app? Or is it GAP Central and it tries to connect to another BLE device (GAP Peripheral) which is Nordic Dev Kit? Also what FWs you run on the devices? Finally have you done any debugging on the embedded side? Like having UART logging and see what SD call returns unexpected error code, if it is asserted in your FW and you reset the board from FW or is it some total hard fault going from Soft Device? There are many things you can (and actually should) do before going further here on the forum...