#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);

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

  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.display();
  delay(2000);
  display.clearDisplay();
}

void loop() {
  int heartRate = simulateMAX30102(); 
  float oxygenSaturation = readOxygenSaturation();
  displayInfo(heartRate, oxygenSaturation);

  delay(1000); 
}

int simulateMAX30102() {
  return random(60, 100); 
}

float readOxygenSaturation() {
  return random(95, 100); 
}

void displayInfo(int heartRate, float oxygenSaturation) {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println(F("Heart Rate: "));
  display.println(heartRate);
  display.println(F("bpm"));
  display.println(F("Oxygen Saturation: "));
  display.print(oxygenSaturation, 2);
  display.println(F("%"));
  display.display();
}