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

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

#define SCREEN_WIDTH 128 // OLED display width,  in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// declare an SSD1306 display object connected to I2C
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);


int callibrating_screen(){
    oled.clearDisplay();
  oled.setTextSize(2);          // text size
  oled.setTextColor(WHITE);     // text color
  oled.setCursor(20,10);        // position to display
  oled.println("Zeroing"); // text to display
  oled.display();
  oled.setTextSize(2);          // text size
  oled.setTextColor(WHITE);     // text color
  oled.setCursor(15,33);        // position to display
  oled.println("sensor..."); // text to display
  oled.display();
  delay(1000);
  oled.clearDisplay();
}
int callibration_done(){
  oled.setTextSize(2);          // text size
  oled.setTextColor(WHITE);     // text color
  oled.setCursor(20,10);        // position to display
  oled.println("Process"); // text to display
  oled.setTextSize(2);          // text size
  oled.setTextColor(WHITE);     // text color
  oled.setCursor(5,33);        // position to display
  oled.println("Completed!"); // text to display
  oled.display();
  oled.clearDisplay();
  delay(1000);
}


int error_1(){
  oled.setTextSize(2);    
  oled.setCursor(18, 25);        // position to display
  oled.println("LOW FiO2"); // text to display
  oled.display();
  delay(500);
  oled.clearDisplay(); 
  oled.display();
  delay(1000);
}
int error_2(){
  oled.setTextSize(2);    
  oled.setCursor(10, 25);        // position to display
  oled.println("HIGH FiO2"); // text to display
  oled.display();
  delay(500);
  oled.clearDisplay(); 
  oled.display();
  delay(1000);
}
int error_3() {  
  oled.setTextSize(2);    
  oled.setCursor(4, 22);        // position to display
  oled.println("Sensor not"); // text to display
  oled.setTextSize(2);    
  oled.setCursor(10, 40);        // position to display
  oled.println("connected"); // text to display
  oled.display();
  delay(1000);
  oled.clearDisplay();
}

int error_4() {
  oled.setTextSize(2);    
  oled.setCursor(25, 24);        // position to display
  oled.println("Battery"); // text to display
  oled.setTextSize(2);    
  oled.setCursor(40, 44);        // position to display
  oled.println("Low!"); // text to display
  oled.display();
  delay(2000);
  oled.clearDisplay(); 
}

void setup() {
  Serial.begin(9600);
  //SSD1306_clear(oled_buf);
  // initialize OLED display with address 0x3C for 128x64
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (true);
  }
}

void loop(){
  
  callibrating_screen();
  callibration_done();
  error_1();
  error_2();
  error_3();
  error_4();
}