Control a 12V DC motor

Hi all..
i am working on a small project where i need to control two 12V 500mA DC Gear Motor in forward and reverse direction and also the speed.
for forward and reverse direction i am using L298 which can be controller using any microcontroller. but again i am stuck at the speed controller. the speed of both the motor should change consistently. i mean speed of both the motor should be same. if i reduce the speed of motor-1 by 10%, the speed of motor-2 should also change by 10%.
i have some ideas but need to confirm if they are reliable to implement it or not,
1) I have planned to use LM317 with digital potentiometer or any DAC at input of L298 pin VS(pin4, power of motor) and the same LM317 can be regulated using DAC or digital potentiometer (not sure, correct me if i am wrong).
2) use P Channel mosfet at the same input pin of L298 and by using the PWM effect i can reduce the voltage of all the motors simultaneously.
can anyone suggest me what is reliable to use in my project. as i have gone though the article where it state that using PWM effect reduces the torque of the motor(not sure).

Hi,

i have some ideas but need to confirm if they are reliable to implement it or not,

Click to expand...

You did not do a internet search on "L298 speed control" ...nor a forum search.

I expect that you do this first.
--> Then you will see that no one uses a pot on Vs.

There are many documents, tutorials, even videos on how to do this.
Lucky you live in a time where we have internet, some ten years ago we didn't have internet.
So use it

Klaus