timeslot - how turn off hfclk crystal

[stefano]

Hi,

when using timeslots I cannot turn off the external crystal that causes an higher consumption. I already read this post and tried to turn off the timer0 (using STOP and SHUTDOWN) but the crystal keep running. In the timeslot I do nothing, but request another timeslot after 2 seconds (no peripheral in use).

As far as the session is opened the crystal remains active, if I close the session then the crystal stops.

To keep things easy I do not activate the radio.

If I use NRF_CLOCK->TASKS_HFCLKSTOP = 1 then I can actually stop the external crystal, but then when using BLE I can no more see the device, so it isn't a viable solution.

Is it the expected behavior or should I make something else to stop the crystal?

P.S.: I'm working with nRF52, SDK11.0.0, and SD s132_nrf52_2.0.0

[stefano]

I solved the problem by specifying NRF_RADIO_HFCLK_CFG_XTAL_GUARANTEED when making the request. This way the external clock is turned off when exiting the timeslot as expected.