Arduino air station

air_quality.ino

#include <PubSubClient.h>
#include <ArduinoJson.h>
#include <dht.h>
#include <Arduino.h>
#include <SPI.h>
#include <SoftwareSerial.h>
#include <LiquidCrystal.h>
#include <Ethernet.h>

#define DHT11_PIN 7
#define RX_PIN 2
#define TX_PIN 3

IPAddress ip(169, 169, 100, 98);
byte mac[] = {
  0x00, 0xAA, 0xBB, 0xCC, 0xDE, 0x02
};

const char *mqtt_server = ""; // Add broker address
const int mqtt_port = 0; // Set the port
const char *mqtt_user = ""; // Add username
const char *mqtt_pass = ""; // Add password
const char *mqtt_client_name = "arduinoClient1"; // Client connections cant have the same connection name


EthernetClient ethClient;
PubSubClient client(ethClient);

SoftwareSerial pmSerial(RX_PIN, TX_PIN);
dht DHT;

int pm1;
int pm2_5;
int pm10;
unsigned long id;
//File myFile;
String s;
StaticJsonBuffer<200> jsonBuffer;
JsonObject& root = jsonBuffer.createObject();

void setup() {
  Serial.begin(57600);
  pmSerial.begin(9600);

  id = 0;
  pm1 = 0;
  pm2_5 = 0;
  pm10 = 0;

  if (Ethernet.begin(mac) == 0)
  {
    Serial.println("Failed to configure Ethernet using DHCP");
    // attempt with fixed ip addr
    Ethernet.begin(mac, ip);
  }

  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);

  delay(2000);

  Serial.println(Ethernet.localIP());
  client.connect("arduinoClient", mqtt_user, mqtt_pass);
  Serial.print("rc=");
  Serial.print(client.state());
  Serial.print("\n");
}

void loop() {
  int index = 0;
  char value;
  char previousValue;

  if (!client.connected())
  {
    if (client.connect("arduinoClient", mqtt_user, mqtt_pass)) {
      Serial.println("connected");
    }
  }

  while (pmSerial.available()) {
    value = pmSerial.read();
    if ((index == 0 && value != 0x42) || (index == 1 && value != 0x4d)) {
      Serial.println("Cannot find the data header.");
      return;
    }

    if (index == 4 || index == 6 || index == 8 || index == 10 || index == 12 || index == 14) {
      previousValue = value;
    }
    else if (index == 5) {
      pm1 = 256 * previousValue + value;
      root["pm1"] = abs(pm1);
    }
    else if (index == 7) {
      pm2_5 = 256 * previousValue + value;
      root["pm2_5"] = abs(pm2_5);
    }
    else if (index == 9) {
      pm10 = 256 * previousValue + value;
      root["pm10"] = abs(pm10);

    }
    else if (index > 15) {
      break;
    }

    index++;
  }

  while (pmSerial.available()) pmSerial.read();

  int chk = DHT.read11(DHT11_PIN);

  if (DHT.temperature == -999 || DHT.humidity == -999) {
    root["temperature"] = "N/A";
    root["humidity"] = "N/A";
  } else {
    root["temperature"] = DHT.temperature;
    root["humidity"] = DHT.humidity;
  }

  sendResults();

  id++;

  delay(5000);
}

void sendResults() {
  // publish to MQTT
  char jsonChar[100];
  root.printTo(jsonChar);
  Serial.println(client.publish("arduino", jsonChar));


  // debug to serial
  root.printTo(Serial);
  Serial.print('\n');
}


// Handles messages arrived on subscribed topic(s)
void callback(char* topic, byte* payload, unsigned int length) {
}