Custom board not advertising ble

Question

Is there an issue with my clock that's causing the BLE not to advertise? The debugger seems to an error on the gatt_params_init() function, which should mean its a RAM address problem. However, nothing gets printed to the debugging terminal providing the adjusted RAM start address. Does anyone have an idea of what's going on? 
 Link to SMD crystal used: ASEK2-32.768KHz-LRT

Akil · Accepted Answer

Thank you, hmolesworth and Jared for your help it's much appreciated. I was able to get the device advertising by removing the 32KHz crystal. Inside the sdk_config.h these are the changes I made: 
 #define CLOCK_CONFIG_LF_SRC 0 
#define NRFX_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 
 I'll have to do more research on what's causing my 32KHz crystal to not allow the device to advertise. 
 Thanks, 
 Akil

hmolesworth · Answer

The ATMEGA328P appears to have VCC at +5V on this board, which is too high when connecting I/O pins directly between the ATMEGA and the nRF52. Reduce the +5V to +3.3V as used on the nRF52 on a new board and see if that works. The absolute maximum on the nRF52 input pins should be below 3.6V, and the ATMEGA drives I/O pins at the ATMEGA VCC level (5V). 
 If the ATMEGA has to use +5V for some reason, then the connected I/O pins will require level translators. Since there is only 1 pin driving into the nRF52, you could try a series resistor on the pin driven to the nRF52 as a kludge, or even a resistor divider or a blocking schottky diode and rely on the nRF52 internal pull-up for the high level.

Custom board not advertising ble

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