nrf_radio_cca_configure, how to use?

[Libertas]

API doc says

__STATIC_INLINE void nrf_radio_cca_configure	(	nrf_radio_cca_mode_t 	cca_mode,
uint8_t 	cca_ed_threshold,
uint8_t 	cca_corr_threshold,
uint8_t 	cca_corr_cnt 
)		
Function for configuring the IEEE 802.15.4 clear channel assessment.

Parameters
cca_mode	Mode of CCA.
cca_ed_threshold	Energy Detection threshold value.
cca_corr_threshold	Correlator Busy Threshold.
cca_corr_cnt	Limit of occurances above Correlator Threshold. When not equal to zero the correlator based signal detect is enabled.

Specs says:for ed_threshold:

PRF[dBm] = ED_RSSIOFFS + ED_RSSISCALE x VALHARDWARE

ED_RSSIOFFS is -92, ED_RSSISCALE is 4.

So if I want to set the threshold 4dBm above -92, shall I put number 1 to hardware register?

I just want to double check that my understanding is correct.

Also I want to confirm that there is no way to set threshold lower than -92dBm.

What about cca_corr_threshold?

[ovrebekk]

Hi

So if I want to set the threshold 4dBm above -92, shall I put number 1 to hardware register?

Yes, that is correct. 

Also I want to confirm that there is no way to set threshold lower than -92dBm.

Correct.

What about cca_corr_threshold?

It is the same as the EDSAMPLE register, as mentioned in this paragraph of the specification:

The conversion from CCAEDTHRES, CCA or EDLEVEL value to dBm can be done with the following equation, where VAL_HARDWARE is the hardware-reported values, being either CCAEDTHRES, CCA or EDLEVEL, and constants ED_RSSISCALE and ED_RSSIOFFS are from electrical specifications:

Figure 18. Conversion between hardware value and dBm

P_RF[dBm] = ED_RSSIOFFS + ED_RSSISCALE x VAL_HARDWARE

Best Regards
Torbjørn

[Libertas]

Thanks. Will give it a try!

[ovrebekk]

Good luck