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

#define SCREEN_WIDTH 128 // OLED width,  in pixels
#define SCREEN_HEIGHT 64 // OLED height, in pixels


//const float PI = 3.14159;
float radius=3.0;
float areaku=0.0;

// create an OLED display object connected to I2C
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

void setup() {
  Serial.begin(9600);

  // initialize OLED display with I2C address 0x3C
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("failed to start SSD1306 OLED"));
    while (1);
  }

  delay(2000);         // wait two seconds for initializing
  oled.clearDisplay(); // clear display

  oled.setTextSize(1);         // set text size
  oled.setTextColor(WHITE);    // set text color
  oled.setCursor(0, 2);       // set position to display (x,y)
  oled.println("Program to calculate an area and circumference of metal disc"); // set text
  oled.setCursor(0, 35);       // set position to display (x,y)
  oled.println("IAC2"); // set text

  oled.display();              // display on OLED
}

void loop() {
// Wait for user to input the circumference
  while (!Serial.available());

  // Read the circumference input from the Serial monitor
  float circumference = Serial.parseFloat();

  // Calculate the radius
  float radius = circumference / (2 * PI);

  // Calculate the area
  float area = PI * radius * radius;

  // Display the result on the OLED display
  oled.clearDisplay(); // Clear the previous display
  oled.setTextSize(1);      // Normal 1:1 pixel scale
  oled.setTextColor(SSD1306_WHITE); // Draw white text
  oled.setCursor(0,0);     // Start at top-left corner
  oled.print("Circumference: ");
  oled.println(circumference);
  oled.print("Area: ");
  oled.println(area);
  oled.display(); // Show the result

  // Wait for a moment before clearing the display
  delay(5000);

  // Clear the display
  oled.clearDisplay();              // display on OLED
}