SparkFun Forums

[CamiloM]

I am fairly new to Arduino and I have been trying to do a project to control 4 DC motors of 3V each. I would like to know how to connect them in order to control their speed and direction separately, as I can connect one with transistors but I'm not really sure how to control multiple motors with h-bridges. I am not sure I can use a motor shield since the motors I'm using are 3V;however, it says that the motors can handle a max load of up to 12VDC. How could I start?

[jbike]

You need 2ea. H bridges, each bridge shield usually controls 2 motors (there are some shields that control many more motors). To control the speed of each motor, you need a total of 4 PWM Arduino pins (one pin per motor, chose from pin 3, 5, 6, 9, 10, or 11). You also need to assign 2 pins for motor direction control for each motor, like maybe pins 2,4,7,8,12,13, and A0,A1.

The H bridge has a separate motor supply input. You could input 5 volts there. The motor supply ground is connected to the Arduino ground. To keep the motor from over speed due to the higher voltage, just use the PWM pins at a lower "on" duty cycle (set a maximum PWM value).

Check your H bridge shields have selectable jumpers so you can stack them the shields without pin conflicts.