#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();

  // Initialize analog pins
  pinMode(34, INPUT);  // GPIO 34 for 6V battery
  pinMode(35, INPUT);  // GPIO 35 for 12V battery
}

void loop() {
  // Example: Display voltage percentage for 6V battery
  int voltage6V = analogRead(34);  // Read voltage from GPIO 34 for 6V battery
  float voltagePercent6V = (voltage6V / 4095.0) * 100;  // Convert to percentage (ESP32 has 12-bit ADC)

  // Example: Display voltage percentage for 12V battery
  int voltage12V = analogRead(35);  // Read voltage from GPIO 35 for 12V battery
  float voltagePercent12V = (voltage12V / 4095.0) * 100;  // Convert to percentage

  display.clearDisplay();
  
  // Draw battery outline for 6V battery
  display.drawRect(10, 10, 50, 25, SSD1306_WHITE);  // Battery body
  display.drawRect(60, 15, 5, 15, SSD1306_WHITE);   // Battery terminal

  // Draw battery bars for 6V battery
  int bars6V = (voltagePercent6V / 100.0) * 4;  // Calculate number of bars (0-4)
  for (int i = 0; i < bars6V; i++) {
    display.fillRect(12 + (i * 12), 12, 10, 21, SSD1306_WHITE);  // Draw each bar
  }

  // Draw battery outline for 12V battery
  display.drawRect(70, 10, 50, 25, SSD1306_WHITE);  // Battery body
  display.drawRect(120, 15, 5, 15, SSD1306_WHITE);  // Battery terminal

  // Draw battery bars for 12V battery
  int bars12V = (voltagePercent12V / 100.0) * 4;  // Calculate number of bars (0-4)
  for (int i = 0; i < bars12V; i++) {
    display.fillRect(72 + (i * 12), 12, 10, 21, SSD1306_WHITE);  // Draw each bar
  }

  // Display voltage percentage for 6V battery
  display.setCursor(0, 40);
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.print("6V: ");
  display.print(voltagePercent6V);
  display.print("%");

  // Display voltage percentage for 12V battery
  display.setCursor(64, 40);
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.print("12V: ");
  display.print(voltagePercent12V);
  display.print("%");

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