ESP8266 + ThingSpeak

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

 
#define ONE_WIRE_BUS  4
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature DS18B20(&oneWire);


unsigned long myChannelNumber = ;          // Replace the 0 with your channel ID
const char* myWriteAPIKey = "";   // Paste your ThingSpeak Write API Key between the quotes 

const char* MY_SSID = "";
const char* MY_PWD = "";

WiFiClient client;


//========================================
//              SETUP
//========================================
void setup() {
  Serial.begin(9600);
  while (!Serial);

  connectWifi();

  WiFi.mode(WIFI_STA);
  ThingSpeak.begin(client); 
}

//========================================
//              LOOP
//========================================
void loop() {
  // Connect or reconnect to WiFi
  if(WiFi.status() != WL_CONNECTED)
    connectWifi();


  // Read Temperature  
  DS18B20.requestTemperatures();
  float temp = DS18B20.getTempCByIndex(0);
  String reply = (String)"Temperature: " + (String)temp + (String)"°C";
  Serial.println(reply);


  //Send Temeprature
  sendTemperatureTS(temp);

  // Wait 20 seconds before sending a new value
  delay(20000);
}




//========================================
//        CONNECT TO WIFI
//========================================
void connectWifi(){
  Serial.print("\nConnecting to "+*MY_SSID);
  WiFi.begin(MY_SSID, MY_PWD);
  while (WiFi.status() != WL_CONNECTED){
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nConnected");   
}


//========================================
//     SEND TEMPERATURE TO THINGSPEAK
//======================================== 
void sendTemperatureTS(float temp){  
  // Write to ThingSpeak. There are up to 8 fields in a channel, allowing you to store up to 8 different
  // pieces of information in a channel.  Here, we write to field 1.
  int x = ThingSpeak.writeField(myChannelNumber, 1, temp, myWriteAPIKey);
  
  // Check the return code
  if(x == 200){
    Serial.println("Channel update successful.");
  }
  else{
    Serial.println("Problem updating channel. HTTP error code " + String(x));
  }
}