NRF52832 Problem with/without 32.768kHz X'tal? Or other Problem?

RE: NRF52832 Problem with/without 32.768kHz X'tal? Or other Problem?

elangel — Fri, 19 Oct 2018 10:58:46 GMT

So, finaly i got it working.

there were some more Problems to solve.

1. Problem: I had to set the Clock source to SYNTH in "device.h" file

/**
* @brief NRF_LF_SRC_XTAL 2
* NRF_LF_SRC_SYNTH 3
* NRF_LF_SRC_RC 4
*/
#define MBED_CONF_NORDIC_NRF_LF_CLOCK_SRC 3

The Option NRF_LF_SRC_RC didn't work. The Program starts...i get some Serial output....and then it stop working.

I'am not sure why, but the Eval Board has the same issue.

2. Problem: Redbear has a own "Softdevice with bootloader.hex"

This Bootloader wants to have XTAL (i guess). So i had to flash the Softdevice 2.0.0 from Nordic.(Redbear Lib just support SD 2.0.0)

3. Problem: RX and TX were swapped.

RE: NRF52832 Problem with/without 32.768kHz X'tal? Or other Problem?

MartinBL — Wed, 10 Oct 2018 11:46:34 GMT

The examples in Nordic's SDK don't use DCDC by default. I have no experience with Redbear libraries and examples though, so I don't know what to expect there. It might very well be that DCDC is enabled.

Anyway, maybe it could be an idea to try a basic example without BLE, just to check that the HW works at all.

RE: NRF52832 Problem with/without 32.768kHz X'tal? Or other Problem?

elangel — Wed, 10 Oct 2018 11:30:52 GMT

Thank you Martin.

Now i have to check all 1000 header files to search the right file for the Clock setting and the DCDC setting.

i found a "device.h" file.

/**
* @brief NRF_LF_SRC_XTAL 2
* NRF_LF_SRC_SYNTH 3
* NRF_LF_SRC_RC 4
*/
#define MBED_CONF_NORDIC_NRF_LF_CLOCK_SRC 4

There i set the clock source to 4, but it didnt help. i think i have to change the dcdc settings.....

RE: NRF52832 Problem with/without 32.768kHz X'tal? Or other Problem?

MartinBL — Wed, 10 Oct 2018 11:19:14 GMT

This is a very common problem.

How can i change the source code of the Softdevice?
You cannot change the Softdevice. You can only change how you choose configure it. How you configure the clock source depends on what SDK version you are using.

Is there no precompiled version for syntethised 32kHz clock and internal LDO?
Not that I am aware.

PS: The nRF52 supports three different 32 kHz clock sources: Crystal, internal RC oscillator, and synthesized. You probably want to use the RC oscillator. A synthesized clock is rarely used since it requires the 32 MHz crystal to run at all times which draws more current than the RC Oscillator.

RE: NRF52832 Problem with/without 32.768kHz X'tal? Or other Problem?

elangel — Wed, 10 Oct 2018 09:55:35 GMT

How can i change the source code of the Softdevice?

Is there no precompiled version for syntethised 32kHz clock and internal LDO?

RE: NRF52832 Problem with/without 32.768kHz X'tal? Or other Problem?

Turbo J — Wed, 10 Oct 2018 09:44:58 GMT

[quote userid="74471" url="~/f/nordic-q-a/39333/nrf52832-problem-with-without-32-768khz-x-tal-or-other-problem"]Is there a problem with the Softdevice without the 32.768kHz X'tal?[/quote]

Yes, because it will be used in the default configuration. Similar story for the DC/DC. You will need to "recover" the module - that erases the flash.

You will have to change the source code in order to use the syntethised 32kHz clock, and to disable the DC/DC usage.