BLE is not advertising on customized nrf52832 board

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Thu, 26 Jul 2018 18:44:25 GMT

The problem was of ground plane. The 49th pin was not grounded properly through the ground plane. we changed the design and its working fine now. Thanks for your help guys.

RE: BLE is not advertising on customized nrf52832 board

kphalak — Mon, 02 Jul 2018 12:12:29 GMT

I was also thinking so haakonsh, but I had used that exact part number for crystal and it works fine. So its at least not a crystal to blame here.
But Ya good point about loading capacitors. I am also eager to see what will end up solving the issue.

RE: BLE is not advertising on customized nrf52832 board

haakonsh — Mon, 02 Jul 2018 09:26:10 GMT

The frequency tolerance and accuracy is to low. You need to aim for a maximum of 50ppm = Ftol + Facc + Aging.

Also The loading capacitors might be too far away from their pins, the trace between C4 and its pin is about 2mm which adds ~2nH inductance. The GND plane is also split and the decoupling capacitors ground connection is therefore through a via who adds an additional ~1nH inductance. This might prevent the crystal oscillator from starting up.

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Fri, 29 Jun 2018 15:34:35 GMT

Actually , the formula to calculate the capacitor value is

C=2CL- Cpcb-Cpin ,where Cpcb+Cpin=4pf , Cl=8pf of crystal

So , C=12pf. But according to attached screenshot, this Cpcb can vary according to the layout, so may br this time, due to decrease in PCB thickness and layout thing, this Cpcb is varying and may be I have to play with C1 and C2 values. What do you say kphalak

RE: BLE is not advertising on customized nrf52832 board

kphalak — Fri, 29 Jun 2018 15:27:40 GMT

Components are fine but I have had read someone mentioning their circuit started working after changing capacitor value to 22pF.

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Fri, 29 Jun 2018 15:24:11 GMT

kphalak I'm using below written 32mhz crystal and load capacitor-

https://www.digikey.ca/product-detail/en/ecs-inc/ECS-320-8-37CKM/XC1547CT-ND/1693716

https://www.digikey.ca/product-detail/en/murata-electronics-north-america/GRM1555C1E120GA01D/490-8169-1-ND/4380462

Are these fine ?

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Thu, 28 Jun 2018 19:46:12 GMT

yes I have already removed the lpkf and checked it with the same code ( previous board code which was not having any lpkf and we changed the congifuration to 32khz RC inside the sdkconfig.h file), still not working.

RE: BLE is not advertising on customized nrf52832 board

kphalak — Thu, 28 Jun 2018 19:30:45 GMT

Crystal part number is good, you can try removing low frequency crystal and change configuration to internal 32kHz RC oscillator.

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Thu, 28 Jun 2018 19:17:49 GMT

Yeah I'm debugging it. But I think the problem is from hardware side only because the code is working fine with the nrf52 DK

and I'm using this lpkf , let me know if its not fine

https://www.digikey.ca/product-detail/en/epson/FC-135-32.7680KA-AC0/SER4084CT-ND/6132704

RE: BLE is not advertising on customized nrf52832 board

kphalak — Thu, 28 Jun 2018 18:59:48 GMT

Yes, 180 degree rotation is fine, no issues with that, still believe it has to do with configuration settings somewhere. You need to debug more to figure, which exact function call is stopping the execution, that will give idea, if any setting or module creating the issue.

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Thu, 28 Jun 2018 18:49:09 GMT

yes, we are getting this issue on all the PCB's. One thing more, the crystal that we were using on the last board(working one), now on this board, its orientation is 180 degree as compared to that and its written on crystal datasheet that both the pads are symmetric and interchangeable, so we can use it in that way, right?

RE: BLE is not advertising on customized nrf52832 board

kphalak — Thu, 28 Jun 2018 18:44:04 GMT

No I dont think so, do you have same issue with multiple PCBs? (In case its a soldering issue)

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Thu, 28 Jun 2018 18:42:28 GMT

Do you think PCB thickness can be the issue? its 0.6mm

RE: BLE is not advertising on customized nrf52832 board

kphalak — Thu, 28 Jun 2018 01:21:11 GMT

That seems to be error handled by stack. And stack stopped the execution typically this should give NRF_LOG with error message as well.

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Thu, 28 Jun 2018 00:44:05 GMT

Its getting stopped at NRF_BREAKPOINT_COND

But the same code working fine with nrf52 DK board

RE: BLE is not advertising on customized nrf52832 board

kphalak — Thu, 28 Jun 2018 00:37:24 GMT

Where does program execution stop? Like you said, it will most likely crystal (LF/HF) or configuration settings that is causing the issue.

RE: BLE is not advertising on customized nrf52832 board

Navdeep — Thu, 28 Jun 2018 00:04:58 GMT

No, I'm not using the smae hex file, I have already changed the SDK_config.h file as new board is having LF crystal.

I have seen alot of posts from for "BLE advertising problem on customized boards" and most of the times, it was because of 32Mhz crystal wrong orientation, but in my case the orientation is fine

RE: BLE is not advertising on customized nrf52832 board

kphalak — Wed, 27 Jun 2018 23:54:10 GMT

So you are saying, its the same project with same firmware hex file, just hardware changes as you mentioned?
you should changed the configuration settings in SDK_config.h regarding 32kHz LF crystal you added.

Did you try on board debugging? does BLE_STACK_INIT function execute successfully?