Problem - Read from Closed Loop Stepper Motor while Rotating

Other Hardware Motors, Mechanics, Power and CNC
10

We tried now also to not use delay, rather millis(), kind of the BlinkWithoutDelay()-method. We made it rotate successfully, but we are still not able to measure position. Output is " End. Pos: 836
", and varies between 790 and 840, but is supposed to be 1000, and should be very accurate, at least we want it to be.

Code:

int Pul = 8;  // PUL+ from driver
int Dir = 9;  // DIR+ from driver
int Ena = 10; // ENA+ from driver

int ENCB = 6; //EB+ from encoder
int ENCA = 5;  //EA+ from encoder

int a = 0;
int b = 0;

int interval_tall = 1;
unsigned long previousMillis = 0;
unsigned long currentMillis = 0;

bool CCW = true;
volatile int pos = 0;

void setup() {
  Serial.begin(115200);   //Baudrate of 115200 or 9600
  
  pinMode(Pul, OUTPUT);
  pinMode(Dir, OUTPUT);
  pinMode(Ena, OUTPUT);
  pinMode(ENCA,INPUT);
  pinMode(ENCB,INPUT);


  
  attachInterrupt(digitalPinToInterrupt(ENCA),readEncoder,RISING);
        
  digitalWrite(Dir,LOW);// dir LOW - clockwise direction of roation (HIGH - CCW)

  
  Serial.print("Start. Pos: ");     //To print and track the position per step
  Serial.println(pos);
  Serial.println("----------");

  
  for (int i=0; i <= 400; i++){ //This loop will perform one revolution
    digitalWrite(Pul, HIGH);
    currentMillis = millis();
    while((unsigned long)(currentMillis - previousMillis) < interval_tall){
      currentMillis = millis();
    }
    
    previousMillis = currentMillis;
    digitalWrite(Pul, LOW);
    
    while((unsigned long)(currentMillis - previousMillis) < interval_tall){
      currentMillis = millis();
    }
 
    previousMillis = currentMillis;
    
    //Serial.println(i);        //print and track step compared to measured rotation
    /*
    Serial.print(" : ");
    Serial.println(pos);
    /*
    Serial.print(" : ");
    Serial.print(currentMillis);
    Serial.println(" : ");
    
    //Serial.println(previousMillis);
    */
  }
  
  Serial.print("End. Pos: ");
  Serial.println(pos);
  Serial.println("----------");

}

// Nothing needed in loop, just want to measure simple rotation back and forth for now
void loop() {
}



void readEncoder(){               //Interrupt function that gets called everytime EA+ rises
  b = digitalRead(ENCB);          //If EB+ already has risen, increase pos-vlaue by 1, else decrease
  if(b > 0){
    pos++;
  }
  else{
    pos--;
  }
}