decoding quadrature encoders

[ice]

Luciano,

when i try the program u recommended [12th april] as below,
there are alot of instances when the program gets confused with direction,
so it sometime increments and decrements.Im not using interrupts

when i move the motor slowly,the problem still persists.

old_val 		VAR BYTE
new_val 		VAR BYTE
direction_bit 	VAR BIT
enc_counter 	VAR WORD
adval			VAR	WORD				' Create adval to store result
potval			VAR WORD
servo_val		VAR	WORD
difference		VAR WORD
	
TRISB=%11111111
enc_counter=32500		
HPwm 0,100,20000	
    
	

	new_val = PORTB & %00000011
start:
	old_val = new_val
	
	
again:
	new_val = PORTB & %00000011
	'LCDOut $fe,1,"no move"
	IF new_val = old_val Then again

	direction_bit = old_val.bit0 ^ new_val.bit1
	
	IF direction_bit = 1 Then  
	
		LCDOut $fe,1,"Last was CW"
		enc_counter = enc_counter + 1
		LCDOut $fe,$c0,DEC enc_counter

	Else
		LCDOut $fe,1,"Last was CCW"
		enc_counter = enc_counter - 1
		LCDOut $fe,$c0,DEC enc_counter	
	
	EndIF
    	GoTo start

Thank you for your responses