Exit from debug mode

[Jérémy Michaud]

Hello,

I did some power measurement on the nrf52 DK with the Nordic profiler kit and the result was way more than what we could expect from a nrf52 (about 1 mA). Even in power off mode, it still needs about this amount of current.

After a search on the devzone, I discovered that it could be because the nrf52 is in debug mode. In this mode, the nrf52 never goes on power down mode et consume way more than in normal mode.

I tried to power reset the chip in order to enter normal mode. But I didn't work.

I also tried nrfjprog --pinreset, but it didn't change anything either.

Finally, I saw on that thread that the code to know whether the debug mode is enabled or not is :

if (DWT->CYCCNT != 0) { bsp_board_led_on(LED); }

And the LED is always on when I run this code.

Is there a solution to exit the debug mode ?

[Bjørn Kvaale]

Bonjour Jérémy. Talked to a colleague here at nordic and his opinion was that a power reset should be able to fix the problem (i.e. get your nrf52 out of debug mode). The nrf51 series had this issue you were describing. If a power reset didn't work there, you could connect an external resistor to the SWDCLK pin (see Tutorials section under link). But since you are using an nrf52, this issue was fixed. Could you explain to me the steps you took to do a power reset?

[Jérémy Michaud]

I oppen the nRFgo Studio application, pressed to the "enable reset pin" button and pressed the reset button of the nrf52. I also tried to switch it off an on again.

[Bjørn Kvaale]

I believe I found the problem. Check out this devzone question. It seems when you use nrfgoStudio to enable the reset pin, the chip remains in debug mode after programming.

Try adding NRF_POWER->RESET =1; to your code instead (for example 1st line in main() function) to set the reset register to 1 (How to reset the nrf52 board). Then you should be able to do a pin reset. Hope that helps!

[Jérémy Michaud]

Hello, thank you for this answer. I tried it but unfortunately, it didn't work.

I did a couple of tests to be more precise about my issue.

First of all, I discovered that when I press the reset button, It works when the Profiler kit is unplugged but not when it is plugged.

Secondly, I am not sure if this problem is linked to debug mode or another issue. I found the codeif (DWT->CYCCNT != 0) { bsp_board_led_on(LED); } on the devzone but I am not actually sure whether this is the right way of doing it or not.

To be sure of the problem, I installed the latest version of the SDK (14.0.0) and I flashed the S132 (5.0.0) to the nrf52 DK. Then I flashed the ble_app_hrs example. I opened the profiler kit sotfware and I have an average consumption of about 1 mA :

And when I am in power off mode, the average consumption is about 700 uA :

I think these values are far away from what it should be, but it could be linked to another problem.

[Jérémy Michaud]

NRF_POWER->RESET is not defined on the SDK, so I did *((uint32_t *) 0x40000544) = 1; instead. It should be the same, right ?