Can I use timeslots without HFXO?

[krnd]

I am using the timeslot API for communication but do not have HFXO.

If I flash my code with NRF_RADIO_HFCLK_CFG_NO_GUARANTEE, it is perfectly running but no data is received. On the other hand if I flash it with NRF_RADIO_HFCLK_CFG_XTAL_GUARANTEED it is running too and also the data will be received.

BUT, my hardware actually does not have an external crystal connected to HFXO (only a 32...kHz at LFXO). Can't I use the timeslot API without HFXO? And why is it actually working if I guarantee it? Also what side effects does this setting without HFXO might have on the operation of the SD?

I am using a nRF52840 with SDK v13.1.0 and SoftDevice S140 v5.0.0-2.alpha.

[bjorn-spockeli]

The 32Mhz crystal is necessary for the RADIO peripheral of the nRF52840 to function properly, i.e. you cannot transmit any BLE packets without it. The SoftDevice(i.e. the BLE protocol stack) will not function properly without the HFXO.

Bjørn