Introduction

Team IOT Group 4:

Amanda Byrne

•

Duncan Houghtaling

Published November 14, 2019 © GPL3+

IOT Project: Temperature and Humidity Sensing

This project uses a DHT11 sensor to read the temperature and humidity and then displays these values on an LCD screen.

IntermediateFull instructions provided15 hours2,834

IOT Project: Temperature and Humidity Sensing

Things used in this project

Hardware components

Particle Argon

DHT11 Temperature & Humidity Sensor (4 pins)

Breadboard (generic)

Jumper wires (generic)

Adafruit Standard LCD - 16x2 White on Blue

Resistor 10k ohm

Micro-USB to USB Cable (Generic)

Software apps and online services

Particle Build Web IDE

ThingSpeak API

Story

Introduction

We created an IOT project that will allow you to know the temperature and humidity in your room or outside any time of the day without having to look at your thermostat or the weather online. In order to accomplish this, we used two particle argons. We connected the first one to the DHT11 sensor, this will allow us to obtain the temperature and humidity of the given environment. This data was then sent to the second Argon, which displayed the temperature and humidity to its attached LCD screen and publishes this data to the internet.

ProjectOverview

We accomplished this project by first wiring the Argons as shown in the circuit schematics. After the Argons were wired into their proper circuit and connected to WIFI, the code for each individual argon was created. The first Argon was coded to collect data from a DHT11 sensor, giving us the temperature and humidity values. This data was then published publicly, allowing the second Argon to receive the temperature and humidity values. The second Argon was coded to display these values on its LCD screen. Once the data was received the second Argon was also coded to send a signal back to the first. This signal tells the first Argon to flash its blue LED light. After the Argons fully communicate, the data is sent to ThinkSpeak. This allows for the data to be monitored online with live updates.

Code

// This #include statement was automatically added by the Particle IDE.
#include <LiquidCrystal.h>

// This #include statement was automatically added by the Particle IDE.
#include <Adafruit_DHT.h>

// This example assumes the sensor to be plugged into CONN2
#define DHTPIN D6     // what pin we're connected to

// Here we define the type of sensor used
#define DHTTYPE DHT11        // DHT 11 

//DHT dht(DHTPIN, DHTTYPE);

LiquidCrystal lcd(5, 4, 3, 2, 1, 0);



void setup() {

  lcd.clear();
  lcd.begin(16, 2);
  lcd.setCursor(0,0);
  lcd.print("Temp");
  lcd.setCursor(0,1);
  lcd.print("Humid");
  Particle.subscribe("Amanda_Duncan_IOTf", f, ALL_DEVICES);
  Particle.subscribe("Amanda_Duncan_IOTh", h, ALL_DEVICES);
    // We open up a serial port to monitor the sensor values
    //Serial.begin(9600); 
   //Serial.println("DHT11 test!");

    //dht.begin();
}

void loop() {
    // Wait a few seconds between measurements.
    delay(2000);


    Particle.publish("Amanda_Duncan_IOT2",PUBLIC);
}

    void f(const char *event, const char *data) {
    
    // Print the data over serial
    lcd.setCursor(6,0);
    lcd.print(data);
    lcd.setCursor(10,0);
    lcd.print("F     ");
    }
    
    void h(const char *event, const char *data) {
    
    lcd.setCursor(7,1);
    lcd.print(data);
    lcd.setCursor(11,1);
    lcd.print("%     ");
    }

// This #include statement was automatically added by the Particle IDE.
#include <ThingSpeak.h>

// This #include statement was automatically added by the Particle IDE.
#include <Adafruit_DHT.h>

// This example assumes the sensor to be plugged into CONN2
#define DHTPIN D6     // what pin we're connected to

// Here we define the type of sensor used
#define DHTTYPE DHT11        // DHT 11 

DHT dht(DHTPIN, DHTTYPE);

bool humid = false;

TCPClient client;


unsigned long myChannelNumber = 907102;
const char * myWriteAPIKey = "VNMAW6BVKGHFVMNY";


void setup() {
    
    ThingSpeak.begin(client);
    
 pinMode(D7, OUTPUT);
 Serial.begin(9600); 
 dht.begin();
 Particle.subscribe("Amanda_Duncan_IOT2", l, ALL_DEVICES);

}

void loop() {
    // Wait a few seconds between measurements.
    delay(2000);

    // Reading temperature or humidity takes about 250 milliseconds!
    // Sensor readings may also be up to 2 seconds 
    float h = dht.getHumidity();
    // Read temperature as Celsius
    float t = dht.getTempCelcius();
    // Read temperature as Farenheit
    float f = dht.getTempFarenheit();

    // Check if any reads failed and exit early (to try again).
    if (isnan(h) || isnan(t) || isnan(f)) {
        Serial.println("Failed to read from DHT sensor!");
        return;
    }
    
    Particle.publish("Amanda_Duncan_IOTf", String (f), PUBLIC);
    Particle.publish("Amanda_Duncan_IOTh", String (h), PUBLIC);

  ThingSpeak.setField(1,h);
  ThingSpeak.setField(2,f);
  
  Serial.print(dht.getHumidity());
  Serial.println("h");
  Serial.print(dht.getTempFarenheit());
  Serial.println("t");

  
  ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);  

  delay(15000); // ThingSpeak will only accept updates every 15 seconds. 

}

    void l(const char *event, const char *data) {
        
            digitalWrite(D7, HIGH);
            delay(2000);
            digitalWrite(D7, LOW);
            delay(1000);
       
    }

Credits

Amanda Byrne

1 project • 2 followers

Duncan Houghtaling

1 project • 2 followers

IOT Project: Temperature and Humidity Sensing