NRF52840 Timer2 Capture and Compare question?

[Ray Chiou]

1.I used Timer2 Capture function

Time Frequency is 1MHz.
Picture1 Current counter should be 33330.
Picture2 Current counter should be 5000.
Picture3 Current counter should be 665.

But the counter is smaller, Can you tell me?




2.I used Timer2 Compare function
Time Frequency is 1MHz.
time_ticks = 4963 is 5m
But  time_ticks = 5000 is 5.04m

[Kenneth]

Hi,

Have you started the external hfclk here?

For instance if you are not using a softdevice you can call NRF_CLOCK->TASKS_HFCLKSTART = 1, ref:
http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52840.ps/clock.html?cp=2_0_0_4_3_2#topic 

If you are using a softdevice you should call sd_clock_hfclk_request() instead.

Best regards,
Kenneth

[Ray Chiou]

Thank you.

I used sd_clock_hfclk_request() is OK.