how do i control DC motor speed and direction?

Hi i found out that the dc motor's speed does not change while i put several different numbers on arduino serial monitor. How do i fix it?? and how do i change direction to opposite(-)? help me, thank you

help me, thank you

Help us help you by posting your wiring diagram and your code. Otherwise no one can have the clairvoyance to know how you are attempting the task or what error(s) you may have in either your wiring or your code.

Lefty

Also motor speed control using PWM only works on a loaded motor. On a free running motor with no load you will not see any speed change due to the motor coasting during the off time.

We still need to see the code and how it is wired up as well.