c = rgData.length
var pA = 0 // previos encoder A value
var iA = 0 // last encoder A rising edge
var cnt = 0  // starting step count
for(var i = 0; i < c; i++){
    fA = 1&(rgData[i]<<0)  //  live encoder-A signal on channel DIO = 0
    fB = 1&(rgData[i]<<1)  //  live encoder-B signal on channel DIO = 1
    if(fA==1 && pA==0){ // encoder A rising edge (A_now = 1 && A_previous = 0)
        if(fB[i]==0){ // encoder B level at time of A-rising edge indicates direction
            //cnt++
            cnt[i] = 1
        }
        else if(fB[i]==1){ // encoder B level at time of A-rising edge indicates direction
            //cnt--
            cnt[i] = 0
        }
        for(var j = iA; j < i; j++){ // assign value (step count) to previous A cycle
            rgValue[j] = cnt
            rgFlag[j] = 1
        }
        iA = i
    }
    pA = fA
}
for(var j = iA; j < c; j++){ // fill the remaining samples
    rgValue[j] = cnt[j]
    rgFlag[j] = 1
}