#include <SPI.h>
#include <Wire.h>
#include <ESP8266WiFi.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "DHT.h"

#define DHTTYPE DHT11
uint8_t DHTPin = D6;
uint8_t DHTPowerPin = D5;

DHT dht(DHTPin, DHTTYPE);

float Temperature;
float Humidity;

#define LENG 31   //0x42 + 31 bytes equal to 32 bytes
unsigned char buf[LENG];

int PM01Value=0;          //define PM1.0 value of the air detector module
int PM2_5Value=0;         //define PM2.5 value of the air detector module
int PM10Value=0;         //define PM10 value of the air detector module

unsigned long lastMillis;


String apiKey = "XXXXX";

// replace with your routers SSID
const char* ssid = "XXXXX";
// replace with your routers password
const char* password = "XXXXX";

const char* server = "api.thingspeak.com";
WiFiClient client;


Adafruit_SSD1306 display(-1);

void setup()
{
 //initialize with the I2C addr 0x3C
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  Serial.begin(9600);
  delay(100);

  Serial.swap();
  delay(100);
  pinMode(DHTPin, INPUT);
  pinMode(DHTPowerPin, OUTPUT);
  digitalWrite(DHTPowerPin, HIGH);

  delay(100);
  dht.begin();

  // Display Text
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(WHITE);

  display.println("PM2.5 Data Logger");
  display.println("(Public)");

  display.setTextSize(1);
  display.println("");
  display.println("by Mark Schramm");
  display.display();

   WiFi.begin(ssid, password);

  delay(2000);




}

void loop() {


   Temperature =  dht.readTemperature(); // Gets the values of the temperature
   //Temperature= round(Temperature*10)/10;
   //delay(250);
   Humidity = dht.readHumidity(); // Gets the values of the humidity
   //Humidity= round(Humidity);
   //delay(250);


if(Serial.find(0x42)){    //start to read when detect 0x42
    Serial.readBytes(buf,LENG);

    if(buf[0] == 0x4d){
      if(checkValue(buf,LENG)){
        PM01Value=transmitPM01(buf); //count PM1.0 value of the air detector module
        PM2_5Value=transmitPM2_5(buf);//count PM2.5 value of the air detector module
        PM10Value=transmitPM10(buf); //count PM10 value of the air detector module
      }
    }
  }


   // Display Text
  display.clearDisplay();
  display.setTextSize(3);
  display.setTextColor(WHITE);
  display.setCursor(10,5);
  display.print(String(PM2_5Value));
  display.setTextSize(1);
  display.setCursor(93,20);
  display.print("PM2.5");
  display.setTextSize(1);

  display.drawLine( 0, 32, 128, 32, WHITE);
  display.setCursor(10,46);
  display.setTextSize(2);
  display.print(Temperature,1);
  display.print("C ");
  display.print(Humidity,0);
  display.print("%");






 if (WiFi.status() != WL_CONNECTED) {

            //display.setCursor(120,0);
            //display.setTextSize(1);
            //display.print(".");

          }else{
            display.setCursor(120,0);
            display.setTextSize(1);
            display.print("@");


          }



  if (millis() - lastMillis >= 1*60*1000UL)
  {
   lastMillis = millis();  //get ready for the next iteration


      if (client.connect(server,80))  // "184.106.153.149" or api.thingspeak.com
      {
        String postStr = apiKey;
        postStr +="&field1=";
        postStr += String(PM01Value);
        postStr +="&field2=";
        postStr += String(PM2_5Value);
        postStr +="&field3=";
        postStr += String(PM10Value);
          postStr +="&field4=";
        postStr += String(Temperature);
          postStr +="&field5=";
        postStr += String(Humidity);
        postStr += "\r\n\r\n";

        client.print("POST /update HTTP/1.1\n");
        client.print("Host: api.thingspeak.com\n");
        client.print("Connection: close\n");
        client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");
        client.print("Content-Type: application/x-www-form-urlencoded\n");
        client.print("Content-Length: ");
        client.print(postStr.length());
        client.print("\n\n");
        client.print(postStr);

        display.setCursor(110,0);
        display.setTextSize(1);
        display.print("!");

      }
      client.stop();


  }

  display.display();

  while(Serial.available() > 0) {
    char t = Serial.read();
  }


  delay(5000);




  }

char checkValue(unsigned char *thebuf, char leng)
{
  char receiveflag=0;
  int receiveSum=0;

  for(int i=0; i<(leng-2); i++){
  receiveSum=receiveSum+thebuf[i];
  }
  receiveSum=receiveSum + 0x42;

  if(receiveSum == ((thebuf[leng-2]<<8)+thebuf[leng-1]))  //check the serial data
  {
    receiveSum = 0;
    receiveflag = 1;
  }
  return receiveflag;
}

  int transmitPM01(unsigned char *thebuf)
{
  int PM01Val;
  PM01Val=((thebuf[3]<<8) + thebuf[4]); //count PM1.0 value of the air detector module
  return PM01Val;
}
//transmit PM Value to PC
int transmitPM2_5(unsigned char *thebuf)
{
  int PM2_5Val;
  PM2_5Val=((thebuf[5]<<8) + thebuf[6]);//count PM2.5 value of the air detector module
  return PM2_5Val;
  }
//transmit PM Value to PC
int transmitPM10(unsigned char *thebuf)
{
  int PM10Val;
  PM10Val=((thebuf[7]<<8) + thebuf[8]); //count PM10 value of the air detector module
  return PM10Val;
}