Hi! I'm a newbie and I need some advice for my school project. I need to control the speed and direction of three little motors with my arduino microcontroller. The motors will only make three very light wheels rotate, but at different speeds, so do I need to use step motors or the regular ones like this http://www.robot-italy.com/product_info.php?products_id=1013 are enough? And do I need to use H-bridges in order to control them or mosfets? Thanks in advice! :)
You need H-bridges only if you need the motors to go backwards too. Do you?
If going only forwards is okay, then all you need is a transistor -- like a logic level MOSFET or even a TIP32 or some other random bipolar. Look up the circuits people recommend for driving a relay (use the search function) and that will give you a good clue.
You will use pulse width modulation (PWM) via analog write to control the motor speed.
Get three of the below small servos, convert to continous rotation, and use the servo library to control rotation speed and direction.
Thank you! It looks simpler with the servo motors. Do I need any other component in order to use them?