WriteMultipleFields.ino

/*
  WriteMultipleFields
  
  Description: Writes values to fields 1,2,3,4 and status in a single ThingSpeak update every 20 seconds.
  
  Hardware: Arduino MKR1000
  
  !!! IMPORTANT - Modify the secrets.h file for this project with your network connection and ThingSpeak channel details. !!!
  
  Note:
  - Requires WiFi101 library version 0.15.3 or newer.
  - This example is written for a network using WPA encryption. For WEP or WPA, change the WiFi.begin() call accordingly.
  
  ThingSpeak ( https://www.thingspeak.com ) is an analytic IoT platform service that allows you to aggregate, visualize, and 
  analyze live data streams in the cloud. Visit https://www.thingspeak.com to sign up for a free account and create a channel.  
  
  Documentation for the ThingSpeak Communication Library for Arduino is in the README.md folder where the library was installed.
  See https://www.mathworks.com/help/thingspeak/index.html for the full ThingSpeak documentation.
  
  For licensing information, see the accompanying license file.
  
  Copyright 2020, The MathWorks, Inc.
*/

#include <WiFiNINA.h>
#include "secrets.h"
#include <DHT.h>
#include "ThingSpeak.h" 

char ssid[] = SECRET_SSID;   // your network SSID (name) 
char pass[] = SECRET_PASS;   // your network password
int keyIndex = 0;            // your network key Index number (needed only for WEP)
WiFiClient  client;

unsigned long myChannelNumber = SECRET_CH_ID;
const char * myWriteAPIKey = SECRET_WRITE_APIKEY;

#define DHTPIN 2
#define DHTTYPE DHT11

//DHT object for temperature and humidity.
DHT dht(DHTPIN, DHTTYPE);

//Method to set up. 
void setup() 
{
  //Initialize serial
  Serial.begin(115200);       
  while (!Serial) 
  {
    ; //Wait for serial port to connect. Needed for Leonardo native USB port only
  }
  
  ThingSpeak.begin(client);  //Initialize ThingSpeak 
}

void loop() 
{

  //Connect or reconnect to WiFi
  if(WiFi.status() != WL_CONNECTED)
  {
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(SECRET_SSID);
    while(WiFi.status() != WL_CONNECTED)
    {
      //Connect to WPA/WPA2 network. Change this line if using open or WEP network
      Serial.print(".");
      WiFi.begin(ssid, pass);  
      delay(5000);     
    } 
    Serial.println("\nConnected.");
  }

  //Read temperature and humidity from DHT sensor
  float temp = dht.readTemperature();
  float humidity = dht.readHumidity();

  //Check sensor readings.
  if (isnan(humidity) || isnan(temp)) 
  {
    Serial.println("Failed to read from DHT sensor!");
    delay(2000);
    return;
  }

  //Set ThingSpeak fields with sensor readings
  ThingSpeak.setField(1, temp);
  ThingSpeak.setField(2, humidity);
  
  //Write to the ThingSpeak channel 
  int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
  if(x == 200)
  {
    Serial.println("Channel update successful.");
  }
  else
  {
    Serial.println("Problem updating channel. HTTP error code " + String(x));
  }
  
  //Wait 20 seconds to update the channel again
  delay(20000); 
}