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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1

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

const int amplitude = 30;  // Amplitude of the sine wave
const float frequency = 0.05; // Frequency of the sine wave
int x = 0; // X coordinate
const int SquareWavefrequency = 2; // Frequency in Hz
unsigned long previousMillis = 0;
bool waveState = false;
const int waveWidth = SCREEN_WIDTH / 4;
void sine_wave();
void drawSquareWave(bool state);
void setup() {
  // Initialize the OLED display
  display.begin(SSD1306_SWITCHCAPVCC, 0x3c);
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 0);
  display.print("Hello, World!");
  display.display();
  delay(1000);
}

void loop() {
  
  unsigned long currentMillis = millis();
  //sine_wave();
  delay(1000);
  // Check if it's time to change the wave state
  if (currentMillis - previousMillis >= 1000 / (SquareWavefrequency * 2)) {
    previousMillis = currentMillis;
    waveState = !waveState; // Toggle the wave state
  }

  display.clearDisplay();
  
  // Call the function to draw the square wave
  drawSquareWave(waveState);

  display.display();
  
  // Small delay for visual clarity
  delay(10);
 
}
void sine_wave()
{
   display.clearDisplay();
  for (int x = 0; x < SCREEN_WIDTH; x++) {
    int y = (amplitude * sin(frequency * (x + millis() / 10.0))) + (SCREEN_HEIGHT / 2);
    display.drawPixel(x, y, WHITE);
  }
  display.display();
  delay(30);
}
void drawSquareWave(bool state) {
  // Define heights for the square wave
  int highY = SCREEN_HEIGHT / 4;      // Top position
  int lowY = 3 * SCREEN_HEIGHT / 4;   // Bottom position

  // Fill rectangles for two waves
  for (int i = 0; i < 2; i++) { // Loop for two square waves
    int xOffset = i * waveWidth; // Offset for each wave

    if (state) {
      display.fillRect(xOffset, 0, waveWidth, highY, WHITE); // Fill top half
    } else {
      display.fillRect(xOffset, lowY, waveWidth, SCREEN_HEIGHT - lowY, WHITE); // Fill bottom half
    }
  }
}