Noob stepper motor shield and motor question

Hey all

I am totally new to Arduino and so far i have completed some super simple projects and now i am stepping up my dive into Arduino.

I have a Arduino Motor Shield R3 and a sparkFun stepper motor(ROB-10846) and want to setup something simple. So all i want to do is get the driver to continuously rotate.

First question: the stepper motor has 4 wires (Red, Green, Blue and Black), but i cant work out what cable is what. Any ideas?

I see on the stepper_oneRevolution sketch that it uses pins 8,9,10,11 but which color should go to which pin?


Grab your multimeter and test for conductivity between the four wires -- it should be obvious that there are two pairs.

One pair goes to M1, the other to M2. Run the test sketch and you have a 50/50 chance it will work. If the motor just jiggles then you need to flip one of the pairs.

The datasheet on Sparkfun's site shows what the colours are.

Thanks for the hints guys, i will give them a try.

One other thing that came to mind, would i need an external power supply or will the USB cable plugged in be ok?


Whenever you're involving a power hungry device in your project it's likely that it will create enough surge or drain in the rest of the circuit to make things act goofy. For your sanity you should use an external power supply.