nrf52832 not working outside debugger.

RE: nrf52832 not working outside debugger.

sch — Mon, 21 Oct 2019 01:27:03 GMT

I have the same problem as you. What is the cause of this problem?

RE: nrf52832 not working outside debugger.

ljaynes — Wed, 24 Oct 2018 20:14:21 GMT

I am currently having this issue. None of the suggestions in the comments have helped. Has anyone correctly identified the issue yet?

RE: nrf52832 not working outside debugger.

hmolesworth — Wed, 28 Mar 2018 15:50:22 GMT

Longshot, but perhaps worth checking if you are still having issues:

1. Measure the impedance between the Gnd connection on the J-Link and the battery; perhaps it isn't quite what is expected.

2. If there are other devices attached (host MCU or external serial port to PC etc) care is required to ensure no port pins are driving into the nRF52832 SoC during a power-down period. In a simple system with a host MCU typically a UART Rx, Tx and the nRF52832 SoC RST pins will be connected between host MCU and nRF52832 SoC. In that simple case either Rx or Reset pins will phantom power the entire nRF52832 SoC if they are left driven high while nRF52832 SoC power is removed. This is perhaps not unexpected if we assume dual internal schottky diode protection (a clamp diode to both GND and VCC) instead of single internal schottky diode (to GND with low breakdown voltage). This means that to power-down the nRF52832 SoC the MCU code must first drive both UART RX and BLE RST pins low, otherwise the supply of (say) 3 volts only drops to 2 volts or so when the supply is switched off and the nRF52832 SoC therefore does not reset.
In a similar manner, connecting a typical FTDI USB serial port to the nRF52832 SoC can unexpectedly phantom power the part, and stop it correctly resetting or powering down unless the FTDI is first removed. This can cause confusing and unexpected behavior. There is an excellent Dialog publication Training_07_DA1458x_prototype_bring_up_guide _Training_07_DA1458x_prototype_bring_up_guide -v1. 2I 2I_ which actually touches on this without mentioning why:
It is recommended that P0_4 and P0_5 are made available for UART communication during production test and board bring-up. Note that, if the two pins are also used as interface to an external MCU, that this MCU will need to be able to high-Z the pin connected to P0_5
The reason is that resetting the test board doesn't work correctly unless drive to the Rx pin is first removed, including drive from any connected FTDI USB serial port or driving low or floating any connected host MCU.

RE: nrf52832 not working outside debugger.

xiaoding — Wed, 28 Mar 2018 14:42:08 GMT

I have the same trouble before. After comment out the NRF_POWER->DCDCEN = 1; Everything goes right.

RE: nrf52832 not working outside debugger.

jublin — Fri, 16 Mar 2018 22:38:30 GMT

I know this is old, but what are your compile flags like? I had a situation where -O0 -g3 would do this. going down to g2/g1 helped.

RE: nrf52832 not working outside debugger.

Nguyen Hoan Hoang — Mon, 01 Jan 2018 19:17:25 GMT

Reset is the normal initialization procedure for the debugger to access the debug port. Once the debugger starts the firmware it can disconnect without halting the MCU hence it continues to work after disconnect but won't after a power cycle as you observed.

RE: nrf52832 not working outside debugger.

Arne Laugstøl — Sun, 31 Dec 2017 08:33:11 GMT

Tanks for tips, I will try it out when I am back in office. In the mean time I would like to share another observation that I did: When I connected to the debugger via j-link command window, made a reset and then a g (go) command - Everything works perfect. Just power-cycling without the debugger, then the device will not advertise anymore.

Also, if I connect to the debugger using RTT-viewer, then everything is perfect. (The RTT-viewer seems to reset the device when I connect) If I then disconnect from debugger by a disconnect in RTT-Viewer - suddenly everything continue to work fine. So, it seems that a reset from the debugger makes a difference compared to a power-up reset. Does that make sense?

RE: nrf52832 not working outside debugger.

RK — Sun, 31 Dec 2017 00:20:46 GMT

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.

RE: nrf52832 not working outside debugger.

Nguyen Hoan Hoang — Sat, 30 Dec 2017 11:44:36 GMT

Try to look for rtt in sdk_config.h. There is a define that enabled it in there some where and disable it there. If it is enabled in there, most likely be used throughout the sdk not just in your code. Do a clean compile after you disable it in the sdk_config.h. That is what I did and it worked for me.

RE: nrf52832 not working outside debugger.

Arne Laugstøl — Sat, 30 Dec 2017 10:28:51 GMT

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

RE: nrf52832 not working outside debugger.

Nguyen Hoan Hoang — Fri, 29 Dec 2017 22:26:03 GMT

Well I am not jlink expert like you. I just know that when I run code with RTT enabled and the Jlink connected it worked fine. Removing the jlink, doesn't work. Disabling the RTT works in all cases and that is what I am sharing here. So by my experiences jlink needs to be connected to for rtt to work. It could be a different issue I don't know. btw you still haven't provided any alternative solution to problem at hand. So what do we need to do to make it work ?

RE: nrf52832 not working outside debugger.

RK — Fri, 29 Dec 2017 22:14:53 GMT

but that's my point - you didn't just say you've found cases you were unable to explain where turning off RTT fixed a bug you couldn't understand. You made the statement that RTT requires JLink to be connected all the time which is just straight up false and not as designed by Segger. The problem with posts like this is someone then does turn off RTT, it randomly fixes the actual bug they do have which is something different and then the incorrect "fact" that 'RTT causes your program to hang if JLink isn't connected' becomes something people find when they search for answers and think it's true. Then people randomly remove RTT, make life hard and never find their actual issues.

If you want to post opinion, go ahead, but at least say 'in my experience' or 'you are supposed to be able to leave RTT code on all the time but I've had some problems with that I never got to the bottom of'.

RE: nrf52832 not working outside debugger.

Nguyen Hoan Hoang — Fri, 29 Dec 2017 22:03:32 GMT

Well, sorry disappoint you but that was a fact for me as I experienced it myself a few times and the same answer also worked for a few people that I know as I said. I just shared what I have experienced in the hope that it could help others with a similar issue. Sorry if that doesn't work for you.

RE: nrf52832 not working outside debugger.

RK — Fri, 29 Dec 2017 21:53:53 GMT

not I who says so - it's Segger who says so and they wrote RTT. They explicitly made it so it's low overhead and you're able to leave it in your code whether connected or not for exactly this reason. No I don't know what the original poster's issue is and they are going to have to look into it some more, however just making statements like "RTT requires the JLink to be connected all the time" which is factually incorrect doesn't really help does it.

RE: nrf52832 not working outside debugger.

Nguyen Hoan Hoang — Fri, 29 Dec 2017 21:45:29 GMT

Ok, if you said so. So it seems not solving this problem for everyone then. But at least it solved the issue for a few people that I know. Can you provide a better solution for the problem then? It does not seems to work for OP by just leaving the RTT enabled.

RE: nrf52832 not working outside debugger.

RK — Fri, 29 Dec 2017 21:37:35 GMT

That is 100% incorrect. RTT writes to a circular buffer and if nothing reads it, it just overwrites. RTT is designed and documented to be left enabled even if you don't have a debugger connected with that exact purpose, ensuring that you don't need to change code depending on whether you are debugging or not.

Quote from the Segger RTT site

A:	SEGGER-RTT uses non-blocking mode per default, which means it does not halt program execution if no debugger is present and J-Link is not even connected. The application program will continue to work.

So whatever the original poster's issue is, it's not that.

RE: nrf52832 not working outside debugger.

Nguyen Hoan Hoang — Fri, 29 Dec 2017 15:48:21 GMT

RTT require the JLink be connected all the time. You need to disable RTT for stand-alone.