// testing a stepper motor with a Pololu A4988 driver board or equivalent
// this version uses millis() to manage timing rather than delay()
// and the movement is determined by a pair of momentary push switches
// press one and it turns CW, press the other and it turns CCW
byte directionPin = 9;
byte stepPin = 8;
byte buttonCWpin = 10;
byte buttonCCWpin = 11;
boolean buttonCWpressed = false;
boolean buttonCCWpressed = false;
byte ledPin = 13;
unsigned long curMillis;
unsigned long prevStepMillis = 0;
unsigned long millisBetweenSteps = 25; // milliseconds
void setup() {
Serial.begin(9600);
Serial.println("Starting Stepper Demo with millis()");
pinMode(directionPin, OUTPUT);
pinMode(stepPin, OUTPUT);
pinMode(ledPin, OUTPUT);
pinMode(buttonCWpin, INPUT_PULLUP);
pinMode(buttonCCWpin, INPUT_PULLUP);
}
void loop() {
curMillis = millis();
readButtons();
actOnButtons();
}
void readButtons() {
buttonCCWpressed = false;
buttonCWpressed = false;
if (digitalRead(buttonCWpin) == LOW) {
buttonCWpressed = true;
}
if (digitalRead(buttonCCWpin) == LOW) {
buttonCCWpressed = true;
}
}
void actOnButtons() {
if (buttonCWpressed == true) {
digitalWrite(directionPin, LOW);
singleStep();
}
if (buttonCCWpressed == true) {
digitalWrite(directionPin, HIGH);
singleStep();
}
}
void singleStep() {
if (curMillis - prevStepMillis >= millisBetweenSteps) {
prevStepMillis += millisBetweenSteps;
digitalWrite(stepPin, HIGH);
digitalWrite(stepPin, LOW);
}
}
