Stepper Motor Controller

We will build our own stepper motor control board and attach it to our cardboard axis from last week.  We will control it all with a potentiometer.  We will use the circuit from the PComp Lab: Controlling a Stepper Motor with an H-Bridge.

We create our circuit on a breadboard.

Check our circuit in the stepper rig.  Powering it using a bench top power supply.

Load up software to Arduino.  Load up the stepper example “MotorKnob”.

We will solder up controller boards.

And we will attach it all to our gantries from last week.


Code for MotorKnob

 * MotorKnob
 * A stepper motor follows the turns of a potentiometer
 * (or other sensor) on analog input 0.
 * This example code is in the public domain.


// change this to the number of steps on your motor
#define STEPS 100

// create an instance of the stepper class, specifying
// the number of steps of the motor and the pins it's
// attached to
Stepper stepper(STEPS, 8, 9, 10, 11);

// the previous reading from the analog input
int previous = 0;

void setup()
  // set the speed of the motor to 30 RPMs

void loop()
  // get the sensor value
  int val = analogRead(0);

  // move a number of steps equal to the change in the
  // sensor reading
  stepper.step(val - previous);

  // remember the previous value of the sensor
  previous = val;