#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <SPI.h>
#include <WiFiClient.h>
#include <PubSubClient.h>
#include <MAX6675.h>

// WiFi settings
const char* ssid = "";
const char* password = "";

// MQTT settings
const char* mqttServer = "192.168.1.15";
const int mqttPort = 1883;
const char* mqttUser = "";
const char* mqttPassword = "";

// MAX6675 settings
int thermoDO = D6;
int thermoCS = D7;
int thermoCLK = D8;
MAX6675 thermocouple(thermoCLK, thermoCS, thermoDO);

// MQTT client
WiFiClient wifiClient;
PubSubClient client(wifiClient);

// Variables to keep track of temperature readings
unsigned long previousMillis = 0;       // will store last time temperature was read
const long interval = 10000;           // interval at which to read temperature (milliseconds)

unsigned int avgSamples = 4;           // take a running average over n values
double avgTemperature;

void setup() {
  // Start WiFi and connect to network
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Start MQTT client
  client.setServer(mqttServer, mqttPort);
  client.connect("Arduino MAX6675");

  avgTemperature = thermocouple.readCelsius();
}

void loop() {
  // Read temperature from MAX6675 and update total temperature
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {
    // save the last time temperature was read
    previousMillis = currentMillis;

    // read temperature
    double temperature = thermocouple.readCelsius();
    avgTemperature = ((avgSamples-1)*avgTemperature + temperature)/avgSamples;

    // calculate and publish average temperature
    client.publish("temperature", String(avgTemperature).c_str());
  }

  // Keep MQTT connection alive
  client.loop();
}