#include <LiquidCrystal.h>
#include <SD.h>

// Define LCD pins
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

// Define potentiometer pins
const int potPin1 = A0;
const int potPin2 = A1;

// Define button pins
const int startandstopButton = 1; 
const int zeroButton = 0;

// Define variables for time recording
unsigned long previousMillis = 0;
const long interval = 1000; // Record values every 1 second
bool recording = false;

// Variables to store the initial potentiometer values
int initialPotValue1 = 0;
int initialPotValue2 = 0;

// Button state variables and debounce interval
int lastStartStopButtonState = HIGH;
int lastZeroButtonState = HIGH;
unsigned long debounceDelay = 50;

// Define SD card chip select pin
const int chipSelect = 10;

// Define file on SD card
File dataFile;

void setup() {
  // Set up serial communication
  Serial.begin(9600);

  // Set up the LCD's number of columns and rows
  lcd.begin(16, 2);

  // Initialize button pins
  pinMode(startandstopButton, INPUT_PULLUP);
  pinMode(zeroButton, INPUT_PULLUP);

  // Initialize the SD card
  if (!SD.begin(chipSelect)) {
    Serial.println("SD card initialization failed!");
    return;
  }
  Serial.println("SD card initialized successfully.");

  // Open file for logging
  dataFile = SD.open("data.txt", FILE_WRITE);
  if (!dataFile) {
    Serial.println("Error opening file!");
    return;
  }
  Serial.println("File opened successfully.");

  // Print initial headers to the file
  dataFile.println("Time,Angle,Force");

  // Print initial message on LCD
  lcd.print("Ready");

  // Store initial potentiometer values
  initialPotValue1 = analogRead(potPin1);
  initialPotValue2 = analogRead(potPin2);
}

void loop() {
  unsigned long currentMillis = millis();

  // Read the state of start/stop button with debouncing
  int startStopButtonState = digitalRead(startandstopButton);
  if (startStopButtonState != lastStartStopButtonState) {
    delay(debounceDelay);
    if (startStopButtonState == LOW) {
      recording = !recording; // Toggle recording state
      previousMillis = currentMillis; // Reset timer
      lcd.clear();
      lcd.print(recording ? "Recording" : "Paused");
    }
  }
  lastStartStopButtonState = startStopButtonState;

  // Read the state of zero button with debouncing
  int zeroButtonState = digitalRead(zeroButton);
  if (zeroButtonState != lastZeroButtonState) {
    delay(debounceDelay);
    if (zeroButtonState == LOW) {
      // Store the initial potentiometer values
      initialPotValue1 = analogRead(potPin1);
      initialPotValue2 = analogRead(potPin2);

      // Clear the LCD screen
      lcd.clear();
      lcd.print("Zeroed");
    }
  }
  lastZeroButtonState = zeroButtonState;

  // Check if it's time to record and recording is active
  if (recording && currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    // Read values from potentiometers
    int value1 = analogRead(potPin1) - initialPotValue1;
    int value2 = analogRead(potPin2) - initialPotValue2;

    // Map analog values to range
    int mappedValue1 = map(value1, 0, 1023, 0, 360);
    int mappedValue2 = map(value2, 0, 1023, 0, 120);

    // Write data to the file
    dataFile.print(currentMillis);
    dataFile.print(",");
    dataFile.print(mappedValue1);
    dataFile.print(",");
    dataFile.println(mappedValue2);

    // Display data on LCD
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Angle (°): ");
    lcd.print(mappedValue1);
    lcd.setCursor(0, 1);
    lcd.print("Force (N): ");
    lcd.print(mappedValue2);
  }
}