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

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

// Declaration for SSD1306 display connected using software SPI (default case):
#define OLED_MOSI 9
#define OLED_CLK 10
#define OLED_DC 11
#define OLED_CS 12
#define OLED_RESET 13

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT,
OLED_MOSI, OLED_CLK, OLED_DC, OLED_RESET, OLED_CS);

int measurePin = A5;
int ledPower = 7;

float voMeasured = 0;
float calcVoltage = 0;
float dustDensity = 0;

void setup(){
Serial.begin(9600);
pinMode(ledPower,OUTPUT);
display.begin(SSD1306_SWITCHCAPVCC);
display.clearDisplay();
display.display();
}

void loop(){
digitalWrite(ledPower,LOW);
delayMicroseconds(280);

voMeasured = analogRead(measurePin);

delayMicroseconds(40);
digitalWrite(ledPower,HIGH);
delayMicroseconds(9680);

calcVoltage = voMeasured*(5.0/1024);
dustDensity = 0.17*calcVoltage-0.1;

if ( dustDensity < 0)
{
dustDensity = 0.00;
}

Serial.println("Raw Signal Value (0-1023):");
Serial.println(voMeasured);

Serial.println("Voltage:");
Serial.println(calcVoltage);

Serial.println("Dust Density:");
Serial.println(dustDensity);

display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(85,22);
display.println("Dust");
display.setCursor(85,38);
display.println("Density");
display.setTextSize(3);
display.setCursor(0,13);
display.println(dustDensity);
display.setCursor(6,43);
display.setTextSize(2);
display.println("ug/m3");
display.display();
display.clearDisplay();

delay(1000);
}