Moving from nRF51 DK to nRF51822 custom board

RE: Moving from nRF51 DK to nRF51822 custom board

FormerMember — Fri, 17 Jun 2016 06:41:45 GMT

Good that you were able to make your board work!

RE: Moving from nRF51 DK to nRF51822 custom board

jtrovato — Thu, 16 Jun 2016 18:16:15 GMT

UPDATE: got the board working! For some reason the 16MHz crystals we order for this build were not working with the circuit. Replacing the crystals got the boards working right away!

RE: Moving from nRF51 DK to nRF51822 custom board

jtrovato — Thu, 16 Jun 2016 16:33:51 GMT

I added an image of the layout to the original post. I tried to add the schematic as an attachment as well. let me know if it got through.

RE: Moving from nRF51 DK to nRF51822 custom board

FormerMember — Thu, 16 Jun 2016 06:16:18 GMT

Could you show what the layout of the chip/antenna part looks like? If you want to keep it confidential, you can create a new support case on www.nordicsemi.com and refer to this thread.

RE: Moving from nRF51 DK to nRF51822 custom board

jtrovato — Wed, 15 Jun 2016 20:01:09 GMT

UPDATE: after changing clock settings to the following I am able to initialize everything (or at least the program now runs through to the infinite loop in main).

#define NRF_CLOCK_LFCLKSRC      {.source   = NRF_CLOCK_LF_SRC_RC,/*NRF_CLOCK_LF_SRC_XTAL,*/      
                                                     .rc_ctiv       = 16, 
                                                     .rc_temp_ctiv  = 16,
                                                     .xtal_accuracy = NRF_CLOCK_LF_XTAL_ACCURACY_20_PPM}

Unfortunately, the device is still not advertising such that my phone can see. I have put in multiple print statements that indicate that the device is advertising; calls to sd_ble_gap_adv_start() returns NRF_SUCCESS

Any ideas?

RE: Moving from nRF51 DK to nRF51822 custom board

jtrovato — Wed, 15 Jun 2016 17:32:03 GMT

Hi Kristen,

Thanks for the reply! Your answers are consistent with what we thought originally. To further address your points:

we actually swapped an nRF51822 with an nRF51422 on our custom HW and they fail in the same spot. Specifically, at line 285 in softdevice_handler.c, err_code = sd_softdevice_enable(p_clock_lf_cfg, softdevice_fault_handler); This looks like the first time the initialization actually makes a call to softdevice compiled code.
We have double checked the crystal and it seems to be mounted correctly. We are not able to see a sine wave on the crystal output, but when removing the crystal, the chip does not function at all.
that's what I thought. Also fits with the fact that both nRF51422 QFAC and nRF51822 QFAC are experiencing the same problem.

We have tried numerous examples, and none have been able to initialize BLE. I think our problem is with interacting with the softdevice.

RE: Moving from nRF51 DK to nRF51822 custom board

FormerMember — Wed, 15 Jun 2016 07:54:24 GMT

1) Code running on nRF51422 (except for ANT), should work without any changes on nRF51822 as well.

2) If you are not sure if the 16 MHz crystal works correctly or not, could you verify that the crystal has been correctly mounted on the PCB, not shifted by 90 degrees for instance? The 32 kHz internal RC oscillator uses the 16 MHz crystal to get the correct frequency.

3) No, there shouldn't be other configurations that you need to set. Since you have a nRF51822 QFAC chip, your chip should have the same amount of flash/RAM as the chip on the DK, 256 kB flash and 32 kB RAM.

Could you test one of the examples from the SDK (if that is not what you already are doing), just to make sure that the BLE initialization is being done correctly.

Does the code with the NRF_CLOCK_LFCLKSRC setting work on your DK?