tamiya motor 3 volt

[aswad]

the frequency is about 19.6khz, use 1 prescale. Ccp1 and ccp2 use timer 2 to generate pwm.
One more, why if i measure the voltage to motor is 5 volt if i dont connect the motor and its fall to 3 volt if i connect it?
It have diode right to protect the oppose current.
Then, its same right 5v dc motor compare with 3 volt motor?

[yonghui]

the frequency is about 19.6khz, use 1 prescale. Ccp1 and ccp2 use timer 2 to generate pwm.
One more, why if i measure the voltage to motor is 5 volt if i dont connect the motor and its fall to 3 volt if i connect it?
It have diode right to protect the oppose current.
Then, its same right 5v dc motor compare with 3 volt motor?

how do u measure? using multimeter?
i think when u connect the motor. the motors start rotate and causing the voltage to fluctuate. if u measure with multimeter, multimeter will take the average voltage which will be lower.

if u have a oscilloscope u can verify your PWM signal with different duty cycle.

[aswad]

Measure? I just calculate based on prescaler 1, 255x200 nano= 51micro sec=19.6khz

[yonghui]

i mean measure the voltage using what?
the frequency can be verified with oscilloscpe.
if you dont have one mayb u can try use pickit 2/ uic00B as logic analyzer:
http://ww1.microchip.com/downloads/en/D ... 0Guide.pdf
or refer cytron magazine volume 8 article on how to : http://www.robothead2toe.com.my/

the most important is you able to set different duty cycle for the PWM