nrf52832 not working outside debugger.

[Arne Laugstøl]

Hi

I have a wired situation in my project. Everything is working fine when I am running my heart-rate device with the debugger. When I detach the debugger or just power-cycle the device behaviour becomes wired. The device still advertise, so I can see it from my phone. But, when I try to connect to it from my phone, it will not connect anymore. If I do "connect jLink" from Segger studio, then everything works fine again.

I am using SEGGER_RTT_WriteString a lot, and I suspected that it could be that the output to the debugger via SWD was blocking when I am not running the debugger. So, I have checked in my code that I am doing SEGGER_RTT_Init() at start, and I have set the SEGGER_RTT_CONFIG_DEFAULT_MODE to 0 (i.e SKIP when buffer is full).

I am using nRF52832 with our own HW, Segger Studio and j-Link Ultra. The sdk version 14.2.0.

Any idea where to start looking for a solution?

Regards Arne

[Arne Laugstøl]

Hi you

Thanks for trying to help me out!

I commented out all the code in SEGGER_RTT_printf and SEGGER_RTT_WriteString. That's the only call I am doing to RTT. That gave the same results as earlier. Everything works fine when J-link is connected. When I disconnect j-link or power-cycling, then I am not able to connect anymore, even if my device is advertising.

Regards Arne

[RK]

Well removing all the RTT calls wasn’t likely to actually help as RTT itself isn’t the problem, as explained, by me and by Segger. So what else could it be, one possibility is that when you connect the debugger that also connects up the UART, did you leave the UART enable code in? That actually can block trying to do UART writes.

Another option is to get it blocked, THEN attach the debugger which you can do to a running board and breakpoint and find out where you are. Segger’s ozone (free) debugger is kind of handy for that, it’s very bare bones, or just use the command line.