Esp8266_Nodemcu v0.9 WoodStove Monitor

Esp8266_Wifi_MQTT_SPI_I2C

/*
 
                   Catalytic Wood Stove Monitor
 This sketch is a working prototype with the ESP8266 board/library.

It connects to local Wifi

It connects to an MQTT server with PubSubClient then:
  - publishes "Data" to local MQTT server where it is picked up by Node-Red 
  
Uses a Digole Display for local information

As per usual all IOT projects are never ending and evolving :) 

*/

#define _Digole_Serial_I2C_  //To tell compiler compile the special communication only, 
#define V33           //if the version of firmware on display is V3.3 and newer, use it
#define RED 0xE0


#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <DHT.h>
#include <max6675.h>
#include <Wire.h>

#include <DigoleSerial.h>

//--------I2C setup
#if defined(_Digole_Serial_I2C_)
#include <Wire.h>
DigoleSerialDisp mydisp(&Wire, '\x27'); //I2C:NodeMCU V0.9: SDA (data line) is on analog input pin 4, and SCL (clock line) is on analog input pin 5 
#endif



#define DHTPIN 2  
#define DHTTYPE DHT22

const char* ssid = "xxxxxxx";
const char* password = "xxxxxxx";
const char* mqtt_server = "192.168.1.128"; // Your MQTT server adress
long previousMillis = 0;      // Timer loop from http://www.arduino.cc/en/Tutorial/BlinkWithoutDelay
long interval = 60000;        //

int ktcSO = 12; // D5 on NodeMCU V0.9
int ktcCS = 13; // D7 on NodeMCU V0.9
int ktcCLK = 14; // D5 on NodeMCU V0.9

MAX6675 ktc(ktcCLK, ktcCS, ktcSO);


DHT dht(DHTPIN, DHTTYPE, 20);
WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;
 char humchar[10];
 char tempchar[10];
 char woodfchar[10];
 char woodcchar[10];

void setup_wifi() {

  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  // Switch on the LED if an 1 was received as first character
  if ((char)payload[0] == '1') {
    digitalWrite(BUILTIN_LED, LOW);   // Turn the LED on (Note that LOW is the voltage level
    // but actually the LED is on; this is because
    // it is acive low on the ESP-01)
  } else {
    digitalWrite(BUILTIN_LED, HIGH);  // Turn the LED off by making the voltage HIGH
  }

}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect("ESP8266Client")) { // Make unique 
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("outTopic", "hello world"); // For Testing purposes 
      // ... and resubscribe
      client.subscribe("inTopic"); // For Testing purposes
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup() {
  pinMode(BUILTIN_LED, OUTPUT);     // Initialize the BUILTIN_LED pin as an output
  Serial.begin(115200);
  dht.begin();
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
  mydisp.begin(); //initiate serial port for display 
  delay(50); 
}

void loop() {

  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  // Wait a few seconds between measurements.
  delay(5000);

  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  float f = dht.readTemperature(true);
  //Read thermocouple temperature in C 
  float DC = ktc.readCelsius();
  //Read thermocouple temperature in f
  float DF = ktc.readFahrenheit();
 
  
  
  // Check if any DHT22 reads failed and exit early (to try again).
  if (isnan(h) || isnan(t) || isnan(f)) {
    Serial.println("Failed to read from DHT sensor!");
    return;

 // Check if any thermocouple reads failed and exit early (to try again).
  if (isnan(DC) || isnan(DF)) {
    Serial.println("Failed to read from Thermo sensor!");
    return;
    
  }

  // Compute heat index in Fahrenheit (the default)
  float hif = dht.computeHeatIndex(f, h);
  // Compute heat index in Celsius (isFahreheit = false)
  float hic = dht.computeHeatIndex(t, h, false);

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.print(" *C ");
  Serial.print(f);
  Serial.print(" *F\t");
  Serial.print("Heat index: ");
  Serial.print(hic);
  Serial.print(" *C ");
  Serial.print(hif);
  Serial.println(" *F");
  Serial.print("Woodstove C = "); 
  Serial.print(ktc.readCelsius());
  Serial.print("\t Woodstove F = ");
  Serial.println(ktc.readFahrenheit());  

  mydisp.clearScreen(); // Configure Display 
  mydisp.setColor(RED);
  mydisp.setFont(123);
  mydisp.setPrintPos(5,2,0);
  mydisp.print(woodfchar);

  
  delay(500); 
  
  
    dtostrf(t,3, 1, tempchar); // dtostrf(floatvar, StringLengthIncDecimalPoint, numVarsAfterDecimal, charbuf);
    dtostrf(h,3, 1, humchar);
    dtostrf(DC,3, 1, woodcchar);
    dtostrf(DF,3, 1, woodfchar);
    
    client.publish("esp8266/1/outTopic", msg); // MQTT data
    client.publish("esp8266/1/temperature", tempchar);
    client.publish("esp8266/1/humidity", humchar);
    client.publish("esp8266/1/woodC", woodcchar);
    client.publish("esp8266/1/woodF", woodfchar);
  }