MBH7BLZ02 not working

[mbozic]

Hi,

I have PCA10028 dev board and Fujitsu MBH7BLZ02 BT module.

I have successfully modified some sample code and when I flash it to nRF module on the PCA board, the code works. I can scan and connect to nRF and use it normally.

Now I'm trying to flash that code to MBH7BLZ02. I've connected MBH to PCA board over debug out connector. I can see the module as nRF51822 in nRFgo Studio, I can flash SoftDevice and application successfully, but MBH module is not seen on scanning. I use S110 for SoftDevice. I've tried S130 too but with same results.

I've also tried to set: SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM, false); in static void ble_stack_init(void) ...with no luck.

My MBH module is connected directly via wires to PCA board since I need to do some testing first, but it seems I just can't get it to work(or advertise).

Am I missing something?

Thank you!

Best regards, Mladen

[MartinBL]

Hi. Do you know what nRF51 revision is on the MBH? I seem to recall it is a 16k variant and the PCA10028 is a 32k? Maybe it is a memory issue.

Have you tried other clock sources? Like the internal RC oscillator, NRF_CLOCK_LFCLKSRC_RC_250_PPM_4000MS_CALIBRATION?

What Softdevice and SDK version number are you using?

Are you able to run simple blinky examples on the MBH?

[mbozic]

Hi,

From nRFgo Studio.: nRF51822 QFAAG00 (0x003c)

It works with NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM! I used a wrong hex file when flashed MBH 1st time I tried changing those.

Where can I read about NRF_CLOCK_LFCLKSRC settings? I have no idea what any of the possible values mean. MBH should have an external oscilator at 16MHz. Or am I wrong?

Thank you!

[MartinBL]

Great! This is a great summary of the possible LF clock sources. Yes, the MBH has an external 16MHz oscillator. The 16MHz crystal is mandatory for BLE applications so otherwise it wouldn't have worked at all.

[mbozic]

Ah, so MBH does not have xternal crystal of 32.768 kHz so that's why NRF_CLOCK_LFCLKSRC_XTAL_20_PPM option isn't working. And it has 16MHz crystal so that's why NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM option works. Thank you for the link!

[MartinBL]

Yes, that is correct. Remember that, as stated in the link, a synthesized clock requires the 16 MHz clock to be running at all times and hence consumes more power than using the LFRC.