mqtt_pub-ds18b20-sub-SSR-mqtt-ts.cpp

//ESP8266 (ESP01) with ESP01 BoB
//MQTT stream temperature data DS18B20 with 1wire on ESP8266 ESP01 and then turn load on/off. perfect for sous vide over the internet.
//shin-ajaran.blogspot.com

#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>

const char *ssid =	"SSID_here";		// cannot be longer than 32 characters!
const char *pass =	"password_here";		//
const char* serverTS = "api.thingspeak.com";
String apiKey ="API_key_here";

// Update these with values suitable for your network.
IPAddress server(192, 168, 1, 104); //node red hosted on ubuntu vm bridged to host.

#define BUFFER_SIZE 100
#define ONE_WIRE_BUS 2  // DS18B20 on GPIO2
#define mySSR 0  // Solid State Relay on GPIO0
#define myPeriodic 5 //in sec | Thingspeak pub is 15sec

void callback(const MQTT::Publish& pub) {
 
  Serial.print(pub.topic());
  Serial.print(" => ");
  if (pub.has_stream()) {
    uint8_t buf[BUFFER_SIZE];
    int read;
    while (read = pub.payload_stream()->read(buf, BUFFER_SIZE)) {
      Serial.write(buf, read);
    }
    pub.payload_stream()->stop();
    Serial.println("");
  } else
    Serial.println(pub.payload_string());

    Serial.println(pub.payload_string());
}//end

WiFiClient wclient;
PubSubClient client(wclient, server);
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature DS18B20(&oneWire);

float oPID = 0;//subs to PID out node red
float setPoint = 30;//temperature setpoint used in PID

void setup() {
  // Setup console
  pinMode(mySSR, OUTPUT);
  Serial.begin(115200);
  delay(10);
  Serial.println();
  Serial.println();
  client.set_callback(callback);
}

void loop() {
 float temp;
  //char buffer[10];
  DS18B20.requestTemperatures(); 
  temp = DS18B20.getTempCByIndex(0); //String tempC = dtostrf(temp, 4, 1, buffer);//handled in sendTemp()
  Serial.print(" Temperature: ");
  Serial.println(temp);
  
  //dummy code to turn load
  if (temp < setPoint ){
    digitalWrite(mySSR, HIGH);   // turn on the load
  }
  else{
    digitalWrite(mySSR, LOW);   // turn on the load
  }
  
  if (WiFi.status() != WL_CONNECTED) {
    Serial.print("Connecting to ");
    Serial.print(ssid);
    Serial.println("...");
    WiFi.begin(ssid, pass);

    if (WiFi.waitForConnectResult() != WL_CONNECTED)
      return;
    Serial.println("WiFi connected");
  }//end if 

  if (WiFi.status() == WL_CONNECTED) {
    if (!client.connected()) {
      if (client.connect("arduinoClient")) {
          client.subscribe("utopic"); //rx cmd via mqtt
         //client.publish("mytopic",String(temp));//tx data via mqtt
      }
    }

    if (client.connected())
      client.loop();

      client.publish("mytopic",String(temp));//tx data via mqtt
  }//end if

  int count = myPeriodic;
  while(count--){
    delay(1000);
  }
  //send TS
  sendTemperatureTS(temp);
 }//end loop
 void sendTemperatureTS(float temp)
{  
  WiFiClient tclient;//not to be confused with "client" in PubSub{}, and wclient for mqtt
   if (tclient.connect(serverTS, 80)) { // use ip 184.106.153.149 or api.thingspeak.com
   //Serial.println("WiFi Client connected ");
   
   String postStr = apiKey;
   postStr += "&field1=";
   postStr += String(temp);
   postStr += "\r\n\r\n";
   
   tclient.print("POST /update HTTP/1.1\n");
   tclient.print("Host: api.thingspeak.com\n");
   tclient.print("Connection: close\n");
   tclient.print("X-THINGSPEAKAPIKEY: " + apiKey + "\n");
   tclient.print("Content-Type: application/x-www-form-urlencoded\n");
   tclient.print("Content-Length: ");
   tclient.print(postStr.length());
   tclient.print("\n\n");
   tclient.print(postStr);
   delay(1000);
   
   }//end if

 tclient.stop();
}//end send to ts