(Solved) Help with WGT51822-S2 module

[Roger Clark]

Hi,

I have been developing using some development modules from WaveShare (based on the nRF51822 QFAC) and they work fine.

However, I'm now trying to use a module better suited small scale deployment, which I sourced from AliExpress

www.aliexpress.com/.../32486456702.html

And the module does not seem to work at all, after I upload exactly the same code as for the QFAC module.

I know the QFAA is 16k RAM and the QFAC is 32k, but I don't think this is the problem, because I tried loading a precompiled bootloader (from RedBearLab) for one of their products which uses the QFAA and I still do not get any advertising packets on BLE :-(

I know the module was originally working, as it came pre-flashed with some sort of BLE to Serial / AT command set firmware, and it was visible on BLE.

However after I erased the chip (using JFlash), and reflashed any other code, I can't get it to do anything.

Is there any other sort of master reset that I may need to do on this device apart from using Erase Chip in JFlash ? (Actually I tried using another GDB compatible SWD programmer and used the "monitor erase_mass" command, which normally totally erases the nRf51, but it didnt make any difference :-(

I guess I can go back to first principals and perhaps load a program that does virtually nothing except toggle a GPIO pin, and run it in the debugger.

But I was hoping there was perhaps something else I could try, before I have to configure GDB etc in Eclipse etc, as I don't have it configured to do on chip debugging at the moment.

Thanks

Edit.

I have since found the module is actually a Wireless-tag.com WGT51822-S2, and the problem is because it does not have a 32kHz crystal So I have changed the title as this is more accurate

[frogofmagic]

1.The module you post from AliExpress, it seems no 32.768 crystal. Did you check it?

2.The AC and AA need different build option, make sure you change to right one.

[Roger Clark]

Which program did the screengrab come from?

I'm building just using Make rather than using a GUI build (long story).

I know that the AC and AA have different build settings, because of the difference in the size of RAM, but I was not aware of any other differences.

In fact as far as I was aware my build target was set for 16k RAM

I'm using this WaveShare development board which uses this module

www.waveshare.com/.../core51822.htm, (actually I have 3 RF modules like this and they are all QFAC)

Looking at the schematic, it has a 32KHz osc

www.waveshare.com/.../Core51822-Schematic.pdf

I don't have a schematic for the module from AliExpress, but I can only see what looks like the 16Mhz crystal and not a 32khz osc

I'll need to look through my code (a lot of which came from mbed) to see if there is a dependency on the 32khz osc

[Roger Clark]

Umm

Looks like this may be the issue

developer.mbed.org/.../

i.e there is code which waits for both the 16Mhz and 32khz clocks to start but the 32khz without any form of timeout (in the mbed cmsis ) :-(

There wasn't an answer to that question on the mbed forum, so I guess I'll need to manually work out what mbed uses the 32khz clock for and whether its necessary or whether there is a work around

i.e is the 32khz clock normally essential ?

[frogofmagic]

The program is MDK-ARM uVision V5.

[frogofmagic]

I'm not familiar mbed, but if you don't have 32K crystal, you can set the clock source to 16M. I saw the link you posted, it might be help. NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos);

to..

NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_RC << CLOCK_LFCLKSRC_SRC_Pos);

or to..

NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_SYNTH << CLOCK_LFCLKSRC_SRC_Pos);

Maybe you can try it.

[Roger Clark]

Thanks

It looks like the mbed file I'm using has been updated since I took snapshot (another long story)

So it now appears to include a timeout on the startup check (which my file doesnt have)

github.com/.../system_nrf51.c

In fact, the newer version of the file has been refactored, and looks like it has other improvements

I'll need to contact the original author of the code - who took the snapshot of the mbed cmsis and ask him whether he thinks I can just grab the latest cmsis from mbed or whether he made some changes

I suspect he just took a snapshot, and copied the files rather than using the github submodule system

But I won't be able to contact him until tomorrow as he is in Canada and they will be asleep by now

Anyway, I think you have solved this mystery.

Thanks

Roger