Hi, thanks...I will try your suggestions regarding the timer/interrupt implementation...but I still don't get what you meant HPWM working on the background...my question probably is how I can change the speed parameter if I needed?

speedR var byte
speedL var byte
speedR = 150
speedL = 150
pause 2000
HPWM 1 ,speedR,10 ' Right Wheel
HPWM 2 ,speedL,10 ' Left wheel

Mainloop:

speedR = 100 ' new value of speed
speedL = 150 '

Goto Mainloop

regards,
tacbanon