Temperature and Relative Humidity Sensor Setup

This is a temperature & relative humidity sensor and LCD display setup using two Particle Argon's and a DHT11 temperature & humidity sensor.

IntermediateShowcase (no instructions)762

Temperature and Relative Humidity Sensor Setup

Things used in this project

Hardware components

Breadboard (generic)

Jumper wires (generic)

Adafruit RGB Backlight LCD - 16x2

DHT11 Temperature & Humidity Sensor (3 pins)

Particle Argon

USB-A to Micro-USB Cable

Single Turn Potentiometer- 10k ohms

Software apps and online services

Particle Build Web IDE

ThingSpeak API

Fritzing

Story

About

When deciding on what to make for our project, we tried to figure out what would be useful as an everyday item that is normally taken for granted. With this in mind, we ended up on temperature and humidity. The temperature is something that is normally overlooked and people don’t look at it more than once. This is why we wanted to make a small system that would automatically update the current temperature and humidity wherever you wanted. This way, there would be a constant reading of the weather. To do this, we used the temperature and humidity sensors along with an LCD screen display to see what the measurements were. The code automatically takes and reads and displays the information on the screen every 5 seconds. Along with this, if interested, it logs all of the past readings to allow for analysis of the past weather.

Project Overview

To complete this project, the first thing that needed to be done was wire all of the Argons in such a way that they had power and used the sensors necessary to create our system. The way that the circuits are wired can be seen in the schematic shown below. Once the circuits were made and given power, two separate strings of code were written to collect the data, send it to its required location, and confirm that the data was received. The first argon circuit is responsible for collecting temperature and humidity data. With the collected data, it made a graph over time in ThingSpeak to see how the values changed over time. Along with this, the data was also sent to the second argon in order to display the values on an LCD screen for easy visualization. The second argon is responsible for displaying the data on the LCD screen. Once the data is received and displayed, it blinks its D7 LED once, then it sends a signal back confirming that the data was received, which is confirmed by the blinking of an LED on the data recording argon. This is done to ensure that the two Argons are communicating with each other. Unfortunately, our LCD screen would not display the data points, even after substantial tweaking using the 10kohm potentiometer we used, and so to ensure that the board was receiving the data, we had the board led flash when it received new data, and then display the data it was being sent in another ThingSpeak graph set as a replacement for the LCD. With this being said, we will still provide the circuit diagrams and code for the LCD screen as we simply tacked on the LED blinking and data export to ThingSpeak to the existing code for the LCD.

Code

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

#define DHTPIN D6 //This defines the pin that is being used to access the LCD Screen

#define DHTTYPE DHT11 // This defines the sensors that are being used to obtain the temperature and humidity data


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

TCPClient client;

unsigned long myChannelNumber = 1250574;
const char * myWriteAPIKey = "6OZIWV6LDC51G5DA";

void setup() 
{
    lcd.begin(16, 2);
        lcd.setCursor(0,0);
    lcd.print("Tempur");
        lcd.setCursor(0,1);
    lcd.print("Humidity");

    ThingSpeak.begin(client);
    pinMode(D7, OUTPUT);

    Particle.subscribe("G45 Iot project Humid", humidity);
    Particle.subscribe("G45 Iot project Temp", temperature);
//This defines everything used in the rest of the code along
//The two subscribe statements correspond to the other argon which is sending the data collected to the LCD screen for it to be displayed
}


void loop() 
{
    // This gives time for the sensors to update and change the temperature and humidity values as they change
    delay(5000);
    
    
    Particle.publish("Group 45 IOT project", PRIVATE);
//This sends the confirm signal to the data recording argon to ensure that they are communicating with each other well
}
    void temperature(const char *event, const char *temperature)
{
        lcd.setCursor(8.,0);
            lcd.print(temperature);
        lcd.setCursor(10,0);
            lcd.print("F     ");
     
          ThingSpeak.setField(1, temperature);
          ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
          
            digitalWrite(D7, HIGH);
                delay(2000);
            digitalWrite(D7, LOW);
                delay(500);
    //This indicates to the LCD argon that the temperature and humidity data has been received, ensuring that communication between the devices has been achieved
}

    
    void humidity(const char *event, const char *humidity)
{
        lcd.setCursor(10,1);
            lcd.print(humidity);
        lcd.setCursor(11,1);
            lcd.print("%     ");
            
          ThingSpeak.setField(2, humidity);
          ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
}
//These last two sets of code prints the received data next to the corresponding title allowing for easy recognition of the number presented

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

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

//This identifies the primary pin output to be read by the DHT sensor
#define DHTPIN D5    

//Defines what the type of the DHT sensor we are using is.
#define DHTTYPE DHT11        

DHT dht(DHTPIN, DHTTYPE);

bool humid = false;

TCPClient client;

//Identifies what ThingSpeak channel and specific channel set to send the data to and write to
unsigned long ThingSpeakChannelNum = 1244806;
const char * APIWriteKey = "TDB5CCVLGVT70DBN";


void setup() 
{
    ThingSpeak.begin(client);
    
 pinMode(D5, OUTPUT);
 pinMode(D7, OUTPUT);
  Serial.begin(9600); 
    dht.begin();

 Particle.subscribe("Group 45 IOT project", handler);
}


void loop() 
{
    delay(5000);

        float humidity = dht.getHumidity();
        //This instructs the argon to take a measurement of the relative humidity as reported by the DHT11 Sensor
 
        float temperature = dht.getTempFarenheit();
        //This instructs the argon to take a measurement of the temperature in Farenheit as reported by the DHT11 Sensor

    //Sends the data recorded by the argon for relative humidity and temperature to the cloud for retrieval by partner's argon
   Particle.publish("G45 Iot project Humid", String (humidity), PRIVATE);
   Particle.publish("G45 Iot project Temp", String (temperature), PRIVATE);

    //This tells what graph plot to send what data to for ThingSpeak
    ThingSpeak.setField(1,humidity);
    ThingSpeak.setField(3,temperature);
    
  
  
  Serial.print(dht.getHumidity());
    Serial.println("humidity");
  Serial.print(dht.getTempFarenheit());
    Serial.println("temperature");

  
  ThingSpeak.writeFields(ThingSpeakChannelNum, APIWriteKey);  
}

//This code confirms that the devices are achieving two-way communicatin by received an LED ping when the partner argon has successfully received exported data
 void handler(const char *event, const char *data)
{
        digitalWrite(D7, HIGH);
             delay(2000);
        digitalWrite(D7, LOW);
             delay(500);
}

Credits

Taylor Hull

1 project • 0 followers

Tdougl11

1 project • 0 followers

Temperature and Relative Humidity Sensor Setup