Advertising issue in nRF52832

[Lalit Kumar Baghel]

I have made a bluetooth beacon based on nRF52832 chip. I am able to write code DeviceDownload\nRF5SDK17009d13099\nRF5_SDK_17.0.0_9d13099\examples\ble_peripheral\ble_app_beacon using segger JTAG edu mini. Platform used is nRFgo Studio. Still my beacon is not discoverable in any of the app i.e., nRFConnect nRFtoolbox, and nRFBeacon. What may be the possible problem?. I have attached schematic and board file for reference.schematic.pdf

[JONATHAN LL]

Hi Lalit,


Assuming that you are able to program the chip correctly (have you tested a simple blinky or pin toggle?) the radio is a sensitive component and can be a source to complications.

In the picture that you have provided it only shows the top layer of the PCB, The antenna should have a keep-out region around it, and there should be no traces or components present within this region and that applies to all sides on the of the PCB, I see that on the top layer this is true and I hope its also true for the bottom layer(assuming you have 2 layers PCB).  Then via stitching around the edge from top layer GND to bottom layer GND is something the to consider, have you followed the guidelines? 

Are you able to see if there is any radio activity from the PCB ?
Have you tried other examples to test the radio? 
Did you program the SoftDevice / what SoftDevice are you using?
By filling out the package type and build code you should get the correct SoftDevice and SDK from here.


Regards,
Jonathan

[Lalit Kumar Baghel]

Hi Janathan,

Bottom layer also have same clearence.

How can i check any radio activity on PCB?

I tried both nRFgo studio and Segger embeddded studio.

I am using S132 softdevice.

Package Type is QF, Build Code is E0

[Lalit Kumar Baghel]

Yes hmoleworth, i am using only 32MHz crystal only.

How to modify code? 

[hmolesworth]

Something like this:

// Add this at the top of sdk_config.h:
#define NRFX_CLOCK_CONFIG_LF_SRC         0
#define CLOCK_CONFIG_LF_SRC              0
#define NRF_SDH_CLOCK_LF_SRC             0
#define NRF_SDH_CLOCK_LF_RC_CTIV        16
#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV    2
#define NRF_SDH_CLOCK_LF_ACCURACY        1 // <1=> NRF_CLOCK_LF_ACCURACY_500_PPM

// Add this in main.c:
static void init_bsp(void)
{
   APP_ERROR_CHECK(nrf_drv_clock_init());
   nrf_drv_clock_lfclk_request(NULL);
   while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0) ;
...

Search for other posts on this subject if this is not clear

[Lalit Kumar Baghel]

where exactly i need to add in main.c ?

[Lalit Kumar Baghel]

I made above changes, beacon worked only for 10 min, did debugging and found crystal was not working. I replaced crystal with new one but still its not working. I think crystal is getting damaged every time, is there any issue with design?

[JONATHAN LL]

Hi, sorry for late reply.

Could you provide the Gerber files?

What Crystal are you using? Could you provide the part number and data sheet?

Only using the High Frequency Crystal Oscillator is ok as long as you configure the sdk_config.h file as Hugh Molesworth said.

// Add this at the top of sdk_config.h:
#define NRFX_CLOCK_CONFIG_LF_SRC         0
#define CLOCK_CONFIG_LF_SRC              0
#define NRF_SDH_CLOCK_LF_SRC             0
#define NRF_SDH_CLOCK_LF_RC_CTIV        16
#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV    2
#define NRF_SDH_CLOCK_LF_ACCURACY        1 // <1=> NRF_CLOCK_LF_ACCURACY_500_PPM

Regards,
Jonathan

[Lalit Kumar Baghel]

Hi Jonathan,

I am using 32MHZ cyrstal, 10pF Load capacitance and 200ppm tolerance.

I did exactly what hmolesworth suggested, beacon worked but only for 10 minutes.

Here is the link of crystal :https://www.evelta.com/ysx211sl-32mhz-10pf-20ppm-4pad-smd-smt-crystal/

Here are the gerber files : 5504.nRF52832 Beacon (2).zip

[JONATHAN LL]

Hi

Nothing seems out of the ordinary whit your PCB, you might have a badly matched antenna so the range might not be grate but if you have two devices right next to each other they should connect fine.  The crystal might be improperly loaded which may make the reference frequency for the radio less accurate, this may result in a bad connection since the carrier frequency might be unstable making a connection unreliable and then the radios will not be bale to communicate.

I will have to aske you to test a different example, preferably the radio test example in the SDK, sett up a unmodulated carrier, then you can use the RSSI-viewer in the nRF Connect for Desktop app to se if there is a RF output form your PCB. 

are you then able to see if there is radio activity for more than 10 minutes?


Regards,
Jonathan