Arduino Uno with Arduino Dual Stepper Motor Driver Shield

I'm working on my first project and wish to drive a single six wire unipolar stepper motor a specified number of revolutions using an Arduino Uno R3 with a stacked Arduino Dual Stepper Motor Drive Shield. I can get the Uno to upload a program such as Blink. So communications are working. How do you know which pins the motor leads are connected to in the stacked configuration? Help please...

Please post a link to the datasheet for the "Arduino Dual Stepper Motor Drive Shield"

I was not aware that there is such a thing.

6-wire stepper motors can usually be treated as 4-wire bipolar motors and can be driven by a specialist stepper motor driver such as the Pololu DRV8825.

Please also post a link to the datasheet for your stepper motor.
And provide details (volts and amps) of the motor power supply.

You may find some useful stuff in Stepper Motor Basics

...R

http://wiki.iteadstudio.com/Arduino_Dual_Step_Motor_Driver_Shield

Heres is the motor link: http://www.robotshop.com/en/rbsoy02-soyo-unipolar-stepper-motor.html

Maybe I have the wrong components. I am building a car that will travel a specified distance between 9 and 12 meters. My thoughts were to program a stepper motor to turn a specific number of revolutions that could be calculated. Any recommendations for something this basic would be appreciated.

That stepper shield does have two "proper" stepper motor drivers. (Many of them only have the far inferior L298 h-bridges).

Your motor is rated at 0.8 amps and the A3967 stepper drivers can do a max of 0.75 amps so you probably won't get full performance from the motor. But the difference is small and the shield looks convenient.

Note that although the motor datasheet says 6v you should power the motor with 12v or more. The stepper driver can be set to limit the current to protect the motor.

Have you looked at the demo code that is linked from the shield datasheet?

A stepper motor is a convenient way of getting a precise number of revolutions. But they are very inefficient and not really suited to battery power.

Another way to measure distance is with a rotary encoder. They can be used with a simple DC motor and that may be more suitable for your car project. If you are content with an accuracy of about 1 revolution you could probably make an "encoder" with a photo-transistor and something to break the beam or to reflect a light once per revolution. In any case I suggest putting the encoder on a slow moving shaft rather than directly on the motor - to make the Arduino's job easier.

...R

Unfortunately for this application I'm limited to 6V. And need more accuracy than just one revolution. Is it even possible to make it work with the components I have and a 5 cell 6v battery? I can't get the stepper to move at all

Try the example in this Simple Stepper Code. It should work with the A3967. You will obviously need to figure out which pins your shield uses for step and direction. That should be fairly obvious from the demo code on the product website.

Stick with that simple code until you get the motor to work.

I presume it will work at 6v but perhaps not at a very high step rate. Start with (say) 10 steps per second - i.e. 100 millisecs between steps.

…R