#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <AccelStepper.h>
#include <Wire.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

const int dirPin = 23;
const int stepPin = 25;
const byte dout_pin = 20;
const byte sck_pin = 21;
int motorSpeed = 0;
long number = 0;
unsigned long currentTime = 0;
int interval= 1000; //1000 mS
int setpoint = 0;

const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};

uint8_t colPins[COLS] = { 7, 6, 5, 4 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 11, 10, 9, 8 }; // Pins connected to R1, R2, R3, R4

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
String keystr = ""; // holds valid ky press
String endstr =""; // holds terminating char#

AccelStepper myStepper(AccelStepper::DRIVER, stepPin, dirPin); //define object as myStepper

void setup() {

  Serial.begin(115200);

  pinMode(dirPin, OUTPUT);
   pinMode(stepPin, OUTPUT);
   pinMode(dout_pin, INPUT);
   pinMode(sck_pin, INPUT);

      // set stepper acceleration and max speed
     myStepper.setAcceleration(500);
     myStepper.setMaxSpeed(1000);

    
  lcd.init();
  lcd.begin(16,2);
  lcd.backlight();
  lcd.clear();
  // Print something
  lcd.setCursor(0, 0);
  lcd.print("motor speed");
  lcd.setCursor(0, 1);
  lcd.print("control");
 delay (4000);
 lcd.clear(); 
 lcd.setCursor(0,0);
 lcd.print("setpoint: ");
 lcd.setCursor(0,1);
 lcd.print("RPM: ");

 int myNum = 0; // set intial setpoint to 0 rpm
 display(myNum);
 
}



void loop() {
  
  
    int setpoint = readkeypad();// get sepoint value from readkeypad function
    
 // set the motor speed:
     motorSpeed = setpoint;
     if (setpoint>1000){
      motorSpeed = 0;
    }

     myStepper.setSpeed(motorSpeed);      
     myStepper.runSpeed();

    // update LCD display every 1 sec
     if (millis()> currentTime +interval)
     { currentTime = millis();
      int myNum = setpoint;
      display(myNum);// update LCD display
     }

}
// ........functions.......

//keypad routine
int readkeypad(){
  char key = keypad.getKey();//gets a char if key pressed
  if (key){
  endstr = (char)key; // assigns the char to endstr
  }

  if(endstr == "#") { //checks for null char '#'
     long number = keystr.toInt(); // if yes,then convert string keystr into an integer
  
      endstr = "";// set the strings to null
      keystr = "";
  return number;
}

    if (isDigit(key)){//checks to see if char is a digit
      keystr += (char) key; //if it is, add it to the string keystr
    return;
  }
  
}

// display setpoint and motorSpeed on LCD
void display(int num) {
   
  lcd.setCursor(10,0);
  lcd.print(num);
  lcd.print("      ");
  lcd.setCursor(5,1);
  lcd.print(motorSpeed);
  lcd.print("          ");
return;
}