#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define trigpin  9
#define echopin  10
#define Mode_pin 3
#define MEASURE_BUTTON 2
#define OLED_RESET 4

int distance1, distance2;
bool circuitOn = false;
bool measureButtonPressed = false;

// Function to check if the button is pressed
bool isButtonPressed(int buttonPin) {
  return digitalRead(buttonPin) == LOW;
  }

  Adafruit_SSD1306 display(OLED_RESET);

  void setup() {
    Serial.begin(9600);
      pinMode(trigpin, OUTPUT);
        pinMode(echopin, INPUT);
          pinMode(Mode_pin, INPUT_PULLUP);
            pinMode(MEASURE_BUTTON, INPUT_PULLUP);
              display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // initialize with the I2C addr 0x3C (128x64)
                display.clearDisplay();
                }

                void loop() {
                  if (digitalRead(Mode_pin == LOW)) {
                      if (isButtonPressed(MEASURE_BUTTON)) {
                            if (!measureButtonPressed) {
                                    measureButtonPressed = true;
                                            delay(100); // Debounce delay
                                                    distance1 = measureDistanceAndDisplay();
                                                          } else {
                                                                  measureButtonPressed = false;
                                                                          delay(1000); // Add delay between readings
                                                                                  distance2 = measureDistanceAndDisplay();
                                                                                          calculateAndDisplayArea();
                                                                                                }
                                                                                                    }
                                                                                                      }
                                                                                                      }

                                                                                                      int measureDistanceAndDisplay() {
                                                                                                        float duration;
                                                                                                          float distance_cm;
                                                                                                          float distance_m;
                                                                                                            digitalWrite(trigpin, LOW);
                                                                                                              delayMicroseconds(2);
                                                                                                                digitalWrite(trigpin, HIGH);
                                                                                                                  delayMicroseconds(10);
                                                                                                                    digitalWrite(trigpin, LOW);
                                                                                                                      duration = pulseIn(echopin, HIGH);
                                                                                                                        distance_cm = (duration / 2) / 29.1;
                                                                                                                        if(distance_cm<100)
                                                                                                                        {
                                                                                                                          display.clearDisplay();
                                                                                                                            display.setCursor(0, 0);
                                                                                                                              display.setTextSize(1);
                                                                                                                                display.setTextColor(WHITE);
                                                                                                                                  display.print(F("Distance: "));
                                                                                                                                    display.print(distance_cm);
                                                                                                                                      display.print(F(" cm"));
                                                                                                                                        display.display();
                                                                                                                                          delay(1000);

                                                                                                                                          return distance_cm; }                          
                                                                                                                                            else if (distance_cm >100) {
                                                                                                                                              distance_m = distance_cm  / 100.0; // Convert to meters
                                                                                                                                              // Display distance on OLED
                                                                                                                                              display.clearDisplay();
                                                                                                                                              display.setTextSize(1);
                                                                                                                                              display.setTextColor(SSD1306_WHITE);
                                                                                                                                              display.setCursor(0,0);
                                                                                                                                              display.print(F("Distance: "));
                                                                                                                                              display.print(distance_m);
                                                                                                                                              display.print(F(" m"));
                                                                                                                                              display.display(); 
                                                                                                                                              return distance_m; }    }                                                  
                                                                                                                                                                                    
                                                                                                                                            
                                                                                                                                          

                                                                                                                                            void calculateAndDisplayArea() {
                                                                                                                                              int area = distance1 * distance2;
                                                                                                                                                display.clearDisplay();
                                                                                                                                                  display.setCursor(0, 0);
                                                                                                                                                    display.setTextSize(1);
                                                                                                                                                      display.setTextColor(WHITE);
                                                                                                                                                        display.print(F("Distance 1: "));
                                                                                                                                                          display.print(distance1);
                                                                                                                                                            display.print(F(" cm"));
                                                                                                                                                              display.setCursor(0, 10);
                                                                                                                                                                display.print(F("Distance 2: "));
                                                                                                                                                                  display.print(distance2);
                                                                                                                                                                    display.print(F(" cm"));
                                                                                                                                                                      display.setCursor(0, 20);
                                                                                                                                                                        display.print(F("Area: "));
                                                                                                                                                                          display.print(area);
                                                                                                                                                                            display.print(F(" cm square"));
                                                                                                                                                                              display.display();
                                                                                                                                                                                delay(2000);
                                                                                                                                                                                }