Hello,
I have attached the motor datasheet, the driver specs (couldnt find the datasheet for the 1.2 version), the schematic of the circuit and the code that i used for this project (which is actually taken from another post here on arduino forums).
What i want this project to do:
- Be able to adjust the speed of the motor with a potentiometer
- Be able to adjust the direction of the motor (clockwise, counter-clockwise)
The problem that i face:
While the driver has Power and RUN LEDs that both turn on when i power the circuit and the RUN LED actually blinks according to the potentiometer position ( pot value low > slow blink , pot value high > faster blink ), my motor doesnt move.
I measured the voltage in the output pins for the motor coils on the driver (A+, A-, B+, B-) and i get 0 V readings even at low potentiometer values on all pins.
What could be the problem?
Also, should i try and write the program with the accelstepper library? Is it worth the hustle for such a simple project?
Thanks in advance!
P.S. The code:
// 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
// updated 17 Oct 2016 to include input from a potentiometer on A0
// potentiometer should vary millisBetweenSteps from 1050 to 27
// NOT TESTED
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
byte potPin = A0; // NEW
int potval; // NEW
unsigned long slowMillisBetweenSteps = 1050; // NEW
int potVal;
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);
millisBetweenSteps = slowMillisBetweenSteps; // NEW
}
void loop() {
curMillis = millis();
readButtons();
readPotentiometer(); // NEW
updateInterval(); // NEW
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);
}
}
void readPotentiometer() { // NEW
potVal = analogRead(potPin);
}
void updateInterval() { // NEW
millisBetweenSteps = slowMillisBetweenSteps - potVal;
}
TB_6600_Test_v0.1a.ino (2.1 KB)