// https://forum.arduino.cc/t/loop-development-for-dac/967224/20

//Based on YWROBOT's LiquidCrystal_I2C library, Library version:1.1
//Also based on the Debounce.ino sketch that comes with Arduino IDE

#include <Wire.h> // Companion for I2C
#include <LiquidCrystal_I2C.h>  //I2C library for LCD
//#include <Adafruit_MCP4725.h> // MCP4725 library from adafruit

// Rotary Encoder Inputs
#define CLK 13
#define DT 12
#define SW 11

// set the LCD address to 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x27, 16, 2);

//Intialize DAC
//Adafruit_MCP4725 MCP4725;

int C_select;
int WhichScreen = 1;                 // This variable stores the current Screen number
boolean hasChanged = true;
const int buttonPin = 11;            // the number of the pushbutton pin
int buttonState;                     // the current reading from the input pin
int lastButtonState = LOW;           // the previous reading from the input pin
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 50;    // the debounce time; increase if the output flickers
float I_Act;                         //Will be used as analog read from Current sense resistor.
int counter = 0;
int currentStateCLK;
int lastStateCLK;
String currentDir = "";
unsigned long lastButtonPress = 0;
int csele;
float I_Set;
float I_Set_previous;
float dac_volt;
int dac_ADC;

//Current (A) setpoints array options
float cur_opt[] = {0, 0.25, 0.5, 0.75,
                   1, 1.25, 1.5, 1.75,
                   2, 2.25, 2.5, 2.75,
                   3, 3.25, 3.5, 3.75,
                   4, 4.25, 4.5, 4.75,
                   5, 5.25, 5.5, 5.75,
                   6, 6.25, 6.5, 6.75,
                   7, 7.25, 7.5, 7.75, 8
                  };


void setup()
{
  // Setup Serial Monitor
  Serial.begin(9600);
  Serial.println("Hello loopDAC World!\n");
  // intialize MCP4725 DAC
  //  MCP4725.begin(0x60);


  //Normalizes I_Set
  I_Set = I_Set_previous;

  //0-5 V = 0-8 A. 5/8 = 0.625 V/A
  dac_volt = (0.625 * I_Set);
  dac_ADC = (4096.0 / 5) * dac_volt; // ***

  // Set encoder pins as inputs
  pinMode(CLK, INPUT);
  pinMode(DT, INPUT);
  pinMode(SW, INPUT_PULLUP);


  // Read the initial state of CLK
  lastStateCLK = digitalRead(CLK);

  // initialize Current set and Current actual
  I_Set = 0;
  I_Act = 1; // Will change into mV / A from current sense resistor.

  // initialize the LCD
  lcd.init();
  lcd.backlight();
  pinMode(buttonPin, INPUT_PULLUP);  // ***

  //Boot screen (Happens on startup)
  lcd.clear();
  lcd.setCursor(0, 0); // Column, line
  lcd.print("LP fiber laser!");
  lcd.setCursor(0, 1); // Column, line
  lcd.print("Booting up...");
  delay(3000);
  lcd.clear();
  WhichScreen = 0;
}

void loop() {


  if (hasChanged == true) {

    switch (WhichScreen) {
      case 1:
        {
          firstScreen();
        }
        break;

      case 2:
        {
          secondScreen();
        }
        break;
      case 0:
        {

        }
        break;
    }
  }

  //-------------------------------
  // BEGIN of the switch debouncing code
  int reading = digitalRead(buttonPin);
  if (reading != lastButtonState) {
    // reset the debouncing timer
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    // whatever the reading is at, it's been there for longer
    // than the debounce delay, so take it as the actual current state:

    // if the button state has changed:
    if (reading != buttonState) {
      buttonState = reading;

      // only toggle the LED if the new button state is HIGH
      if (buttonState == HIGH) {
        hasChanged = true;
        WhichScreen++;
      }
    } else {
      hasChanged = false;
    }
  }
  lastButtonState = reading;
  // END of the switch Debouncing code
  // --------------------------------------
  if (WhichScreen > 2) {
    WhichScreen = 1;
  }
}

void firstScreen()    //Main function. Displays current set /  current actual. Click rotary to set current
{
  lcd.clear();
  lcd.setCursor(0, 0); // Column, line
  lcd.print(" I_Set: ");
  lcd.setCursor(10, 0);
  lcd.print(I_Set);
  lcd.setCursor(0, 1);
  lcd.print(" I_Act: ");
  lcd.setCursor(10, 1);
  lcd.print(I_Act);
}

//Second screen = Adjust current (A) function. Displays current set / current actual.
//Spin to Adjust - auto updates. Click to confrim. MCP only chages on click.

void secondScreen()
{
  lcd.clear();
  lcd.setCursor(0, 0); // Column, line
  lcd.print("  Set current:");
  lcd.setCursor(0, 1); // Column, line
  lcd.print(" I_Set: ");
  lcd.setCursor(10, 1);
  lcd.print(I_Set);
  while (WhichScreen = 1) {                             //While loop to display current set as adjusted. Prevents MCP from setting voltage until break
    // Read the current state of CLK
    currentStateCLK = digitalRead(CLK);

    // If last and current state of CLK are different, then pulse occurred
    // React to only 1 state change to avoid double count
    if (currentStateCLK != lastStateCLK  && currentStateCLK == 1) {

      // If the DT state is different than the CLK state then
      // the encoder is rotating CCW so decrement
      if (digitalRead(DT) != currentStateCLK) {
        counter ++;
        currentDir = "CW";
      } else {

        // Encoder is rotating CW so increment
        counter --;
        currentDir = "CCW";
      }
      //Perhaps unecessary
      csele = counter;

      //Current select Array
      I_Set = cur_opt[csele];

      //0-8 A I set = 0-5 V V_in.
      dac_volt = (0.625) * I_Set;
      //ADC to volts
      dac_ADC = (4096.0 / 5) * dac_volt; // ***

      if (counter < 0) {
        counter = 0, I_Set = 0, csele = 0;
      }
      if (counter > 31) {
        counter = 31, I_Set = 8.00, csele = 32;
        delay (100);
      }

      //Serial debug
      Serial.println("Direction: ");
      Serial.print(currentDir);
      Serial.print(" | Counter: ");
      Serial.println(counter);
      Serial.print("I_Set:");
      Serial.println(I_Set);
      Serial.print("Csele:");
      Serial.println(csele);
      Serial.println("dac_volt");
      Serial.println((dac_volt));
      Serial.println("dac_ADC");
      Serial.println((dac_ADC));

      //update current select
      lcd.clear();
      lcd.setCursor(0, 0); // Column, line
      lcd.print("  Set current:");
      lcd.setCursor(0, 1); // Column, line
      lcd.print(" I_Set: ");
      lcd.setCursor(10, 1);
      lcd.print(I_Set);
    }
    // Remember last CLK state
    lastStateCLK = currentStateCLK;

    // Read the button state
    int btnState = digitalRead(SW);

    //If we detect LOW signal, button is pressed
    if (btnState == LOW) {
      //if 50ms have passed since last LOW pulse, it means that the
      //button has been pressed, released and pressed again

      //intiate check for MCP coltage set.
      if (millis() - lastButtonPress > 50) {
// ***        Serial.println("Button pressed!");
// ***        delay(100);

        if  (I_Set_previous != I_Set) {

          //      MCP4725.setVoltage(dac_ADC, false);
          Serial.print(dac_ADC); Serial.println(" false setVoltage to MCP");
          I_Set_previous = I_Set;
          WhichScreen = 1;
          //Serial debug for loop.
          Serial.println("End While");
        }
        // Remember last button press event
        lastButtonPress = millis();
        if (WhichScreen = 1) { //if statement may be unecessary. Break on click instead.
          break;
        }
      }
      // Put in a slight delay to help debounce the reading
      delay(1);
    }
  }
  WhichScreen = 1;
}