#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);

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

  
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  
  // clear OLED
  display.clearDisplay();
  display.setTextSize(1);  
  display.setTextColor(SSD1306_WHITE); 
  display.setCursor(0, 0);
  display.display(); 
}

void loop() {
  float temperatureC = simulateLM35();
  int heartRate = simulateMAX30102();
  float oxygenSaturation = simulateOxygenSaturation();
  

  displayInfo(temperatureC, heartRate, oxygenSaturation);
  delay(1000); 
}

float simulateLM35() {
  return random(20, 30); 
}

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

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



void displayInfo(float temperatureC, int heartRate, float oxygenSaturation ) {
  display.clearDisplay(); 

  display.setCursor(0, 0);
  display.print("Temp: ");
  display.print(temperatureC, 2);
  display.println(" C");

  display.setCursor(0, 16);
  display.print("Heart Rate: ");
  display.print(heartRate);
  display.println(" bpm");

  display.setCursor(0, 32);
  display.print("Oxygen Sat: ");
  display.print(oxygenSaturation, 2);
  display.println(" %");



  display.display(); 
}