NRFX temperature driver (nRF52840, SDK 17.0.0)

[dzabel]

Hi,

the nrfx driver for the internal temperature sensor has been introduced with SDK 16,0.0, Since I started developing with SDK 15.02, I have used so far the old HAL driver, which works fine.

Now I tried to switch to the new NRFX driver (using non-blocking mode) and ran into problems.

• The first issue was that NRFX_TEMP_ENABLED is needed in sdk_config.h, but this is not included in the template sdk_config.h files to be found in <SDK_ROOT>/config/nrf52840. I added than "#define NRFX_TEMP_ENABLED 1" to my project-specific sdk_config.h, so the link succeeded.
• The second issue is, that nrfx_temp_init() runs into a hard fault on trying to enable the interrupt, nrfx_temp.c, line 82. This happens only if the SoftDevice is included in the build.  I can build two different versions of my software, one includes the SoftDevice, and one does not include it (helps with debugging if I don't need Bluetooth).If I build my software without the SoftDevice, the driver seems to work as expected. The fault handler message is "SOFTDEVICE: INVALID MEMORY ACCESS"

Since the NRFX_TEMP_ENABLED is not included in the template sdk_config.h, I am suspicious if thas new driver has ever been tested.

Any ideas?

Regards

  Dirk

[Patrick]

Have you tried using the soft device specific functions for getting temp? If I am not mistaken, the info center page for the temp library provides more detail on how to get the core temp when using the SD. 

[Einar Thorsrud]

I second that. You must use the SoftDevice API to use the TEMP peripheral, as that is protected (and used) by the SoftDevice. Therefore writing to TEMP registers directly is not allowed and will trigger an invalid memory access fault.

[dzabel]

Thank you. I had the false expectation that the NRFX driver cares for this and thought it would be "cleaner" to use the NRFX driver, but if I look into the source, I can see it does not. Than I will stick with my old code which uses sd_temp_get() if SOFTDEVICE_PRESENT is defined.