UNO Stepper Tester

A project log for 3D Printer

Attempt to dive into 3D printing

willbadenwillbaden 06/12/2015 at 10:560 Comments

Since the axis are coming together, I wanted to be able to test the capability of the stepper motors without attaching a computer. The first test of the y axis included using Repetier host and an UNO using Teacup, which required hooking up the computer and sending G code to the UNO. Instead I wanted a pot to adjust the speed and direction of the movement. Here is what I came up with:

Stepper Motor Control with Speed Direction outputs

This program will send step pulses out to a step/dir driver board 
for testing

It is controlled by a potentiometer that will change the speed as it
changes from 2.5V.  Below 2.5V is CCW: 0V is max speed, above 2.5V is CW:
5V is max speed


//The lower the number the faster the speed
// stepMaxSpeed = 15 is 15 uS delay between step pulses
int stepMaxSpeed = 250;
//The higher the number the slower the speed
// stepMinSpeed = 100 is 100 uS delay between step pulses
int stepMinSpeed = 1000;
//Set pins for output to step/dir driver board
int stepPin = 2;  //13 can be used for the LED
int stepDirection = 3;
int analogMotorControlPin = A0;

//Analog value Read
int MotorControlValue = 0;

void setup() {
  // put your setup code here, to run once:
  pinMode(stepPin, OUTPUT);
  pinMode(stepDirection, OUTPUT);

void loop() {
  // put your main code here, to run repeatedly:
  int stepDelay = 0;
  MotorControlValue = analogRead(analogMotorControlPin);
  //Set direction and speed using the analog input
  // This has a dead band between 500-524.  Here the motor will not move
  if (MotorControlValue > 524) {
    digitalWrite(stepDirection, 1);
    stepDelay = map(MotorControlValue, 524, 1023, stepMinSpeed, stepMaxSpeed);
  }else if (MotorControlValue < 500) {
    digitalWrite(stepDirection, 0);
    stepDelay = map(MotorControlValue, 0, 500, stepMaxSpeed, stepMinSpeed);
  }else {
    //if analog input is in deadband, don't allow for pulses to be sent out
    stepDelay = 0;
  if (stepDelay != 0) {
    digitalWrite(stepPin,1); //step driver board
  //Delay microseconds for the driver board to recognize change
  // may need to be altered for the driver boarxd selected.