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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
#define SCREEN_ADDRESS 0x3C  // Default I2C address for SSD1306

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup() {
  // Initialize the display
  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.display();
  delay(2000);  // Pause for 2 seconds
  display.clearDisplay();
}

void loop() {
  // Example: Display voltage percentage
  int voltage = analogRead(A0);  // Read voltage from analog pin
  float voltagePercent = (voltage / 1023.0) * 100;  // Convert to percentage

  display.clearDisplay();
  
  // Draw battery outline
  display.drawRect(10, 10, 50, 25, SSD1306_WHITE);  // Battery body
  display.drawRect(60, 15, 5, 15, SSD1306_WHITE);   // Battery terminal

  // Draw battery bars based on voltage percentage
  int bars = (voltagePercent / 100.0) * 4;  // Calculate number of bars (0-4)
  for (int i = 0; i < bars; i++) {
    display.fillRect(12 + (i * 12), 12, 10, 21, SSD1306_WHITE);  // Draw each bar
  }

  // Display voltage percentage
  display.setCursor(0, 40);
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.print("Voltage: ");
  display.print(voltagePercent);
  display.print("%");

  display.display();
  delay(1000);  // Update every second
}