Using Simple Timer with SoftDevice

RE: Using Simple Timer with SoftDevice

Einar Thorsrud — Tue, 06 Apr 2021 13:40:47 GMT

I see.. Are you using custom HW? If so, can you let me know which crystal you are using and if more variants, which CL value the specific one you use have? Also please share your circuitry around the HF crystal and value of your load caps.

RE: Using Simple Timer with SoftDevice

Aftab — Tue, 06 Apr 2021 10:58:12 GMT

Hi,

I made sure that 16MHz clock source is being used by using the code you posted above.

Still I see lot's of variation, the clock source have no positive effect on it.

RE: Using Simple Timer with SoftDevice

Einar Thorsrud — Thu, 25 Mar 2021 13:35:41 GMT

Hi,

Unless you explicitly start the HFXO (crystal oscillator) the HFINT (RC oscillator) is used, and that has a quite low accuracy. I suggest you start the HFXO and measure again. You can do that for instance using nrf_drv_clock_hfclk_request() or using this code snippet:

    // Start 64 MHz crystal oscillator.
    NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_HFCLKSTART    = 1;

    // Wait for the external oscillator to start up.
    while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0)
    {
        // Do nothing.
    }