No CCW rotation

Question

The code runs in CW(flex) motion but when switch is detected or hit will not run in CCW(dflex) motion.When the mechanical limit switch is manually pressed or hit the motor will attempt something but it does not stop the CW motion and it definitely does not change its direction to CCW.

Working with bipolar stepper motor that has a 47Gear reduction

const int LS = 2; // input pin for the Limit Switch
int detectState = 0; // Variable for reading the encoder status
const int stepPin = 5; 
const int dirPin = 4; 
const int enablePin = 3;
double GReduction = 47;
int T1 = 100;
int T2 = 100;
int Z = 0;
int Walk_flag = 1;
double angle = 0;

///////////////////////////////////////////// //flex(int ang,int tm); // an = angle, tm= time

void setup()
{
pinMode(LS, INPUT); //Set pin 2 as input
pinMode(stepPin,OUTPUT); //Set pin 5 as input
pinMode(dirPin,OUTPUT);//Set pin 4 as input
pinMode(enablePin,OUTPUT);//Set pin 3 as input
attachInterrupt(digitalPinToInterrupt(LS), LS_Hit, CHANGE);
////////////homing algorithm 
//T1=100;
dflex();
Serial.begin(9600);
angle=0;
flex(90,1);
}

void loop() {
 flex(30,100);
  delay(1000);
  if( detectState==HIGH)
 {
dflex();
 }
}
///////////////////////////////////// CW motion

void flex(int ang,int tm) // an = angle, tm= time
{
   double ZZ;
   ZZ= (800.0*ang*GReduction/360.0);  
   //String val = String(ang/360);
   Serial.println(ang);
  for(int x = 0; x <ZZ; x++) {    //angle control
    digitalWrite(dirPin,HIGH);
    digitalWrite(enablePin,HIGH);
    digitalWrite(stepPin,HIGH);
    delayMicroseconds(T1);
    digitalWrite(stepPin,LOW);
    delayMicroseconds(T1);
    }
digitalWrite(enablePin,LOW);
  }

/////////CCW motion
void dflex() 
{
   digitalWrite(enablePin,HIGH);
   digitalWrite(dirPin,LOW); //Changes the rotations direction
   int LS_status=digitalRead(LS);
    while(digitalRead(LS)) {
      if(digitalRead(LS)==HIGH)
      {
        break; 

      }
    digitalWrite(stepPin,HIGH);
    delayMicroseconds(T2);
    //delay(100/T); // One second delay
    digitalWrite(stepPin,LOW);
    //delay(T/100); // One second delay
    delayMicroseconds(T2);
}
  }

void LS_Hit()
{
 digitalWrite(enablePin,LOW);
 angle=0; 
  detectState =! detectState;
}

score 1 · Answer 1 · edited Apr 11 '19 at 00:12

There is an issue in the following part of your code:

while(digitalRead(LS))
{
    if(digitalRead(LS) == HIGH)
    {
       break; 
    }

    digitalWrite(stepPin, HIGH);
    delayMicroseconds(T2);
    //delay(100/T); // One second delay
    digitalWrite(stepPin, LOW);
    //delay(T/100); // One second delay
    delayMicroseconds(T2);
}

The steps inside this while loop will never be done, as the entry condition to the while loop is the same as the break condition.

To be specific, the control will enter the while loop only when digitalRead(LS) return a HIGH, but immediately after it enters the while loop, you are doing the same check again, and if the function returns a HIGH, you are breaking out of the while loop. This will never allow the function to make the motor go in the reverse direction.

There are several other issues with your code, but this one speaks the loudest.

No CCW rotation

1 Answers1