[AVR] DC motor PWM and AVR ?

[bianchi77]

Guys,

How can I control the RPM of DC motor with PWM on AVR?
Any experiences ?
I use 12V 0.14A DC motor for CPU cooler..

Any infos will be appreciated..

Thanks

 

[milan.rajik]

DC motor has to be connected to L293B and IN1 and IN2 pins of L293B are connected to microcontroller and EN1 pin of L293B is connected to PWM1 or PWM2 pin of microcontroller. CPU cooler fan rotates in one direction only. If OUT1 and OUT2 of L293B are +ve and -Ve respectively then IN1 has to be made high and IN2 low. Use a PWM of 1 KHz and change the duty cycle of PWM to vary the speed of motor.