Blink an LED in Emulated System OFF ??

RE: Blink an LED in Emulated System OFF ??

Jørn — Fri, 21 Apr 2017 09:21:33 GMT

Hello Kmoto

I apologize for the late reply, we had holidays here all of last week.

I have dug further into this, and it seems it is related to the same problem as in the link I provided you earlier.

I have tested with both the old nrf_delay.h file that comes with SDK9, and the new one supplied in the link I provided. With the old file the chip will eventually enter a hardfault, but with the new file I have successfully blinked a led while in emulated system off, using both nrf_delay_ms and nrf_delay_us.

Best regards

Jørn Frøysa

RE: Blink an LED in Emulated System OFF ??

kmoto — Tue, 11 Apr 2017 18:26:28 GMT

Hi Jorn, I am using nrf51822, and SDK version 9 with armgcc, not an IDE. Your link does not seem to be the same problem because I am using nrf_delay_ms() in other parts of the code and it works fine in those.

RE: Blink an LED in Emulated System OFF ??

kmoto — Fri, 07 Apr 2017 13:12:38 GMT

Also, I am not using an IDE. I am using armgcc with a Makefile.

RE: Blink an LED in Emulated System OFF ??

Jørn — Fri, 07 Apr 2017 06:24:47 GMT

What IDE are you programming with? Please see this link, and check if that solves your problem devzone.nordicsemi.com/.../

RE: Blink an LED in Emulated System OFF ??

RK — Fri, 07 Apr 2017 03:23:50 GMT

well if the GPIOs are accessible and the processor is running the nrf_delay_ms will work, so you need to work out why it's not. It doesn't do anything except execute no-ops in a loop so there's no way it can't work.

RE: Blink an LED in Emulated System OFF ??

kmoto — Fri, 07 Apr 2017 02:55:28 GMT

Actually I can still turn on the LED right after the System OFF command (or turn it off if it was previously on). So either GPIO is still working or there is a delay in activation of the System OFF.

RE: Blink an LED in Emulated System OFF ??

RK — Fri, 07 Apr 2017 02:32:13 GMT

Nowhere in that list does it say that GPIO is active in emulated system off mode so nrf_delay_ms will work but you may not be able to actually change the state of an IO line.