HFXtal doesn't start

[Sergio T]

I made an application based on ble_app_uart example using s130_nrf51_2.0.1_softdevice.hex and I have 2 boards:

- 1 nrf51DK

- 1 target board using nRF51822-QFAA H0 (version 3).

In the nRF51DK I cust the 32.768kHz crystal (I cut SB1) and the code runs on the board compiled for nRF51822-QFAA - RAM and ROM settings are correct and tested even Bluetooth is working.

My target board doesn't have 32.768kHz crystal, only 16MHz crystal. Well, my board doesn't work. 

I commented the lines to start Bluetooth activity, removed the power_manage call so that code runs without power downs: the code runs on the nRF51DK but not on my target. I checked hardware and all is ok.

From what I can see, the 16 MHz crystal doesn't start (I use the same crystal and 12pF capacitors as in nRF51DK board). What can it be? Any setting I am forgetting?

[Einar Thorsrud]

Hi,

Have you tried to debug your application? What state is it in? How do you see that the 16 MHz crystal does not start? Note that the crystal is not started by default, as the internal 16 MHz RC oscillator is used initially. The SoftDevice will start the crystal oscillator when it needs an accurate clock for the radio, and the application can choose to start it in case it needs an accurate clock (for instance for a timer or similar).

[Sergio T]

Hi Einar:

In the meantime the code is running without the power_manage() call in the main loop. I still don't get it why it doesn't work but I'll try to find out.
It would be great if I could debug directly on my target board. Can I do it through the nRF51 DK SWDIO and SWDCLK lines? I use SES as development environment.

[Einar Thorsrud]

Hi,

Please continue in the other thread, as it seems to cover the same issue.