Use of QDEC for 10 rpm and lower

[SteveUK]

We are using the QDEC in an nRF52832 and our rotation speeds are 0 to 15rpm, usually around 10rpm. Is there any fundamental reason the QDEC can not be used in this case? We are seeing some sign flips but am not sure if it's HW or a filtering issue.

Thanks

[Amanda Hsieh]

Hi Steve, 

Do you enable filtering register DBFEN? See Debounce filters doc. You could enable NRFX_QDEC_CONFIG_DBFEN (for  nRF_QDEC) or QDEC_CONFIG_DBFEN (for QDEC peripheral driver - legacy layer configuration) in the sdk_config.h.

-Amanda H.

[SteveUK]

Amanda, 

Yes, we use the debounce filters. My specific question is this:

"Is there a minimum revolutions per minute (rpm) at which the QDEC will not work correctly?"

Thanks,

Steve

[Amanda Hsieh]

Hi Steve, 

We think it should work fine even if rpm is 0. But if the signal is a bit noisy, it might help to enable debounce filters, https://infocenter.nordicsemi.com/topic/ps_nrf52833/qdec.html?cp=4_1_0_5_16_2#concept_pk1_gwd_4r

-Amanda H.