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

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

#define OLED_RESET -1 //Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C //See datasheet for Address
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

int mapsen = 0; // Set MAP sensor input on Analog port 0
int NUM_SAMPLES= 500;  // number of samples
float sum = 0;                    // sum of samples taken
int sample_count = 0; // current sample number
float input_voltage = 4.72; //measured with multimeter
float peakBoost;

void setup() {
 Serial.begin(115200);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  display.clearDisplay();
  display.display();
  delay(2000);

}
 
void loop() {
  sum = 0;
  sample_count = 0;
  while (sample_count < NUM_SAMPLES) {
        sum += float(analogRead(mapsen));
        sample_count++;
        delay(0.5);
    }   
 float out_voltage = (sum / NUM_SAMPLES * input_voltage) / 1024;
 float Pabs = (out_voltage*3294.1176/input_voltage-1052.4228)*0.0145; //absolute pressure in mbar *0.0145

  if (Pabs < 1) {
    Pabs = 0;
  }
 
 peakBoost = max(peakBoost,Pabs);
 
 Serial.println(Pabs);
 Serial.print("\t");
 Serial.println(out_voltage,4);

 display.clearDisplay();
 display.setTextColor(SSD1306_WHITE);
 display.setTextSize(1);
 display.setCursor(0, 0);
 display.print("BOOST");
 display.setTextSize(4);    
 display.setCursor(0, 12);    
 display.print(Pabs,1);
 display.setCursor(80, 26);
 display.setTextSize(2);
 display.print(peakBoost,1);
 display.fillRect(0, 47, (Pabs * 10), 16, WHITE);
 display.drawRect(0, 47, 130, 16, WHITE);
 display.drawRect((peakBoost * 10), 47, (129 - (peakBoost * 10)), 16, WHITE);
 if (Pabs >= 10) {
 display.setTextSize(1);
 display.setCursor(68, 0); 
 display.print("OVER BOOST");
 }  
 display.display();
}