Harware issue with BLE, and use of BLE UART example

[Nicols]

Hello everyone,

In my current application, I am using nRF52832, with the SDK 11.0. I have a problem with the BLE connectivity, which I think is a hardware issue.

With the nRF52832 DK, the BLE UART example is working perfectly. But when I use it with my custom board (with only the nRF and the BLE antenna, and not the PCA10040), the bluetooth connectivity isn't working, even when i remove the functions for the state, buttons and leds handlers (buttons_led_init and power_manage).

Here are my schematics : 

So my question is : is the problem coming from my schema, or maybe, on my PCB, the antenna is too far from the nRF ?

Thank you in advance for your reply.

[Andreas]

Hi,

 

Are you not able to establish any communication even if you place the boards right next to each other? What is C_L for your crystal? Have you measured increased current consuption, e.g. by setting up a TX carrier with the radio test example?

 

Best regards,

Andreas

[Nicols]

Hello, thanks for your reply.

For the CL, i have C8 and C12, two capacitor of 12pF, on the top right, as described in the datasheet.

Concerning the communication, even when the device is next to the board it doesn't communicate.

But I found out that maybe my problem is also from the software : when i run my code, it get stuck on the function softdevice_handler_init(), that is inside SOFTDEVICE_HANDLER_INIT(&clock_lf_cfg,NULL), inside ble_stack_init(); at this point :

I found someone who did have the same issue : https://devzone.nordicsemi.com/f/nordic-q-a/14019/stuck-in-softdevice_handler_init. But the solution that are given didn't worked.

[Andreas]

Hi,

 

What is CL, speficied parameter for your 32 MHz crystal? 8pF? Have you triple checked three times that your 32MHz crystal is not mounted 90 degrees off? Also, you're either having a 32kHz crystal present, or specify using the internal RC right?

 

Seeing as this runs fine on a DK I do not believe that the SW is the cause.

 

Best regards,

Andreas

 

 

[Nicols]

It's 12pF for CL.

I already checked the 32KHz crystal several times before for other applications, and now everthing work (i used TWI, PWM...) with it, so i don't think the issue come from that.

[Andreas]

Hi,

 

If specified CL is 12pF then try to resolder C8 and C12 = 20 pF.

 

Best regards,

Andreas