Quadrature encoder code question

[yzou_ua]

After init etc., I calculate the speed in following way. Could someone help me find anything wrong here?? Buz the measured result varies time by time(when running the motor at constant speed).

while(1)
{

if(TMR3<23000)
{
if(POS1CNT=0)
{CntsRev=0;
CntsRev+=1;}

Cnts=POS1CNT+(CntsRev-1)*MaxCnt; // The total pulse number during above time period

Speed_rad=2*3.14159*Cnts/ppr/TMR3; // Speed in rad/s
}
}

 

[Iamventure]

Is this step correct??? {CntsRev=0;