26 August 2012

V0.9 is the current published version on this website.
It has come to my attention that I have inadvertently left a #define set to force the ADC reference voltage to be 1.024V.
#define VREF1024 in sysconfig.h.

This was defined to test the possibility of increasing the ADC’s resolution at low expected back EMF feedback voltages.

The ultimate intention is the reference voltage will be chosen based upon the expected feedback voltage, a lower reference for lower speed demands.

In addition to provide a better back EMF feedback term, the intention is to also take a median average of several consecutive ADC readings each BEMF sample interval.
Presently this is a single sample, and is very vulnerable to random noise affecting the sample.

Further research into this method can be found on this page.