Arduino with Johnson Motor

Hi.I am a student and as part of project we have decided to a four wheeled robot.We have an arduino Uno.And we have four 12v 100rpm johnson motors.Can you please suggectwhich motor shield will be good for this? Is it good to use two L293 motor drivers or is there any other motor driver for four dc motors?

We need way more info that you have given to recommend anything. Particularly, we need to know the stall current draw of the motor.

THe Johnson motor draws a current of minimum 800mA and maximum 9A

Also today we have decided to use only two motors. I know L293d is a motor driver used to drive motor in both directions.But I think it gives for upto 2A only.Please help me

Pololu have a large range of motor drivers; have a look at their range here.

THe Johnson motor draws a current of minimum 800mA and maximum 9A

Since your motor has a max current of 9 amps, you need to get an h-bridge driver (for each motor) that can handle that current.

But it isn't so simple as finding one that is 9 amps. Instead, you want to add an extra percentage to that amperage, and size to that. Somewhere around 15-30% - so shoot for a minimum of around 12 amps or so. This is because you never want to drive any component or system to it's max rating, and instead size for above that rating as a safety margin.

Hi, I'd agree with JimboZA, you are looking at some serious current so need a controller that also takes care of current limiting and you should put fuses in the main supply lines that carry the motor current.

Can you post the spec/type number of the motor please, Johnson motor means nuthin.

Just like I drive a Ford, what tyres should I put on it? (Yes, I know round black ones)

Tom........ :slight_smile: