File content as of revision 1:72e6e124a7e6:

#include "mbed.h"
#include "PolledQEI.h"




void PolledQEI::setSampleFrequency(int i = 10000) {
    _sample_uSec = i;
    _actEncPos = 0;
    _ticker->attach_us( this, &PolledQEI::check, _sample_uSec );
}

int PolledQEI::pos(void) {
    return _actEncPos;
}

int PolledQEI::dir(void) {
    return _dir;
}

int PolledQEI::rev(void) {
    return _actEncRev;
}

void PolledQEI::countRev(void) {
    if (_dir) {
        _actEncRev++;
    } else {
        _actEncRev--;
    }
}

void PolledQEI::init(PinName a, PinName b, PinName z = NC) {

    _phaseA = new DigitalIn( a );
    _phaseA->mode( PullUp );
    _phaseB = new DigitalIn( b );
    _phaseB->mode( PullUp );
    if (z != NC) {
        _phaseZ = new InterruptIn( z );
        _phaseZ->mode( PullUp );
        _phaseZ->fall(this, &PolledQEI::countRev);
    }
    _actEncRev = 0;
    _actEncPos = 0;
    _dir = 0;

    _ticker = new Ticker;
}

void PolledQEI::check (void) {
    unsigned int pA = _phaseA->read();
    unsigned int pB = _phaseB->read();
    unsigned int newV = 0, diffV = 0;


    // convert gray to binary
    if ( pA ) {
        newV = 3;
    }
    if ( pB ) {
        newV ^= 1;
    }

    diffV = last - newV;			    // difference last - new
    if ( diffV & 1 ) {				    // bit 0 = value (1)
        last = newV;				    // store new as next last
        _actEncPos -= (diffV & 2) - 1;  // bit 1 = direction (+/-)
        _dir = (diffV & 2)?CW:CCW;
    }
}