// Forum: https://forum.arduino.cc/t/stepper-w-2-buttons-pushed-and-potentiometer-got-stuck/1166311


//lcd
#include <LiquidCrystal.h>

LiquidCrystal lcd(23, 22, 24, 25, 26, 27);

const int trigPin = 9;
const int echoPin = 10;
long duration;
int distanceCm, distanceInch, distanceMm;

// motor
const int button_left = 2;  // Push button for CW
const int button_right = 3;  // Push button for CCW
const int driverPUL = 7;    // PUL- pin
const int driverDIR = 6;    // DIR- pin
const int spd = A0;     // Potentiometer
const int leftLED = 12;
const int rightLED = 13;

int pd = 500;       // Pulse Delay period

void setup() {
  Serial.begin(115200);
  //lcd
  lcd.begin(16, 2);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);


  //motor
  pinMode (driverPUL, OUTPUT);
  pinMode (driverDIR, OUTPUT);
  pinMode (button_left, INPUT_PULLUP);
  pinMode (button_right, INPUT_PULLUP);

}

void loop() {
  pd = 2090 - analogRead(spd) * 2;

  //lcd
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distanceCm = duration * 0.034 / 2;
  distanceInch = duration * 0.0133 / 2;
  distanceMm = duration * 0.34 / 2;
  Serial.println(distanceMm);
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(distanceMm);
  lcd.print(" mm ");
  delay(300);
  lcd.setCursor(0, 1);
  lcd.print("Distance: ");
  lcd.print(distanceInch);
  lcd.print("inch");
  delay(10);

  //motor
  if ( digitalRead(button_right) && digitalRead(button_left) ) 
    return;

  if ( !digitalRead(button_right) ) 
    digitalWrite(driverDIR, LOW);

  if ( !digitalRead(button_left) ) 
    digitalWrite(driverDIR, HIGH);

  digitalWrite(rightLED, !digitalRead(button_right));
  digitalWrite(leftLED, !digitalRead(button_left));

  digitalWrite(driverPUL, LOW);
  delayMicroseconds(50);
  digitalWrite(driverPUL, HIGH);
  delayMicroseconds(pd);
}