saline_squeezer.ino

/**
 * 
 */
const int dirPin = 8;
const int stepPin = 9;
const int enablePin = 7;
const int sw = 6;

const int delayMicros = 500;  //Delay between each step
const int maximumSteps = 230; 
      int _currentStep = 0;



//DIR high = ccw
//DIR low = cw


/**
 * Go back to home position
 * 1. Set DIR pin to HIGH to make motor turn CW
 * 2. Send step pin (HIGH,WAIT,LOW,WAIT) to driver to move 1 step
 * 3. Keep send step until switch is on (LOW)
 */
void goHomePosition() { 

  //Set direction to CW
  digitalWrite(dirPin, HIGH); 
  while(digitalRead(sw)){
    digitalWrite(stepPin, HIGH);
    delayMicroseconds(delayMicros);
    digitalWrite(stepPin, LOW);
    delayMicroseconds(delayMicros);
  }
  _currentStep = 0;
}

/**
 * Run motor CCW for given steps
 */
void runStepperCCW(int steps) { 

  //Set direction to CCW
  digitalWrite(dirPin, LOW);

  //Run motor, each step contain 1 Rising edge and 1 Falling edge
  for (int i = 0; i < steps; i++) { 
    //Stop when maximum steps is reached
    if(_currentStep>maximumSteps) break;
    
    digitalWrite(stepPin, HIGH);
    delayMicroseconds(delayMicros);
    digitalWrite(stepPin, LOW);
    delayMicroseconds(delayMicros);
    _currentStep++; 
  }
  Serial.println(_currentStep);
}


void setup() {
  Serial.begin(115200);
  pinMode(enablePin, OUTPUT);
  pinMode(stepPin, OUTPUT);
  pinMode(dirPin, OUTPUT); 
  pinMode(sw, INPUT_PULLUP); 
  digitalWrite(enablePin, LOW);
}

void loop() {
  const int steps = 230;//90
  
  const int stepAtHighestFlowrate = 20;
  const int stepAtLowestFlowrate = 230;
  const int stepAtHalfFlowrate = (20+230)/2;


  //These code will run back to home and go to position 1
  //then go back to home and go to position 2
  //then go back to home and go to position 3
  delay(3000);
  goHomePosition();
  delay(3000);
  runStepperCCW(stepAtHighestFlowrate);
  delay(3000); 
  goHomePosition(); 
  delay(3000);
  runStepperCCW(stepAtHalfFlowrate); 
  delay(3000);
  goHomePosition(); 
  delay(3000);
  runStepperCCW(stepAtLowestFlowrate); 
  delay(3000);


  //These lines of code will run back to home position
  //and go to position 1 
  //and go to position 2
  //and go to position 3 
  
  goHomePosition(); 
  delay(3000);
  runStepperCCW(stepAtHighestFlowrate); 
  delay(3000);
  runStepperCCW(stepAtHalfFlowrate-_currentStep); 
  delay(3000);
  runStepperCCW(stepAtLowestFlowrate-_currentStep); 
  delay(3000);  
}