Published April 24, 2023

Light Identified Temperature Detection

We are using a temperature sensor to turn on a light that determines what to wear for the day.

IntermediateFull instructions provided12 hours5

Things used in this project

Hardware components

DHT11 Temperature & Humidity Sensor (4 pins)

LED (generic)

Breadboard (generic)

Particle Argon

Jumper wires (generic)

Photo resistor

Resistor 1k ohm

Software apps and online services

ThingSpeak API

Story

Have you ever stepped outside ready to go and its snowing but you're still wearing flip flops? That won't be an issue ever again with our project. We are using a DHT11 Temperature and Humidity sensor to tell what to wear for the day. A photo resistor light sensor will indicate if its daytime or not and will then allow the circuits to indicate the weather. Blue means its less than 46 degrees. (You might want to dress a little warm.) Red means its over 74. (Time for summer clothes.) Green means its just right and between 46 and 74 degrees. (Wear what you desire.) There are also white and yellow lights indicating the humidity. If the humidity level is over a certain threshold, the yellow light will turn on. If its not, the white light will stay on. This will generally mean its either raining or snowing.

Flow Chart

This flow chart shows how each of the argons interact with each other and the computer. The computer sends a power signal to each of the argons to power them on. The first argon takes that power to transmit temperature and humidity data to both the computer and the second argon. It also receives photo resistor data from the second argon and the computer telling it to turn on or off the different LEDs. These LEDs indicate whether it is daytime or nighttime.The second argon transmits photo resistor data to the computer and the first argon. It also receives temperature and humidity data from the first argon and the computer.

Flow Chart

Image of DHT11 Particle Argon Circuit

DHT11 Circuit

Image of Photo Resistor and LED Circuit

Photo Resistor and LED Circuit

Temperature vs Time Data

This graph shows the temperature data being recorded by the DHT11 temperature sensor over the course of 1 minute. Between 45 and 60 seconds, the temperature increased to over 74 degrees, so the second argon was notified and turned off the green LED and turned on the red one.

Temperature vs Time

Humidity vs Time Data

This graph shows the humidity data being recorded by the DHT11 humidity sensor over the course of 1 minute. Between 45 and 60 seconds, the humidity level increased from about 39% to about 67% humidity. During this time, the second argon was notified and the white LED was turned off and the Yellow LED was turned on.

Humidity vs Time

Photo Resistor Data

This graph shows the photo resistor data. When the photo resistor senses light, the value is about 400 on the graph. When the photo resistor is covered to where no light is showing, the value drops down to about 200. When this happens, the circuit goes from closed to open, and the LEDs all turn off. At this time, the data is sent to the other argon and an indicator light lets us know if the circuit is open or closed. Green means the circuit is closed and red means the circuit is open.

Photo Resistor On/Off

Youtube Video

Photo Resistor and LED Circuit

This is the circuit diagram for the Photo Resistor and LEDs. The Particle Argon is powered by the computer and a power output is sent through a photo resistor. When there is light shining on the photo resistor, the circuit is activated and the corresponding LEDs will activate. When it is dark, the circuit will be open and the LEDs will not be activated. A 1k Ohm resistor is used to drop the voltage so that it is usable. A jumper cable is used to ground the LEDs on the other side of the breadboard. Each LED is connected to a separate pin that controls which one will be turned on. The blue LED is activated when the temperature reading is below 46 degrees Fahrenheit, the green LED is activated when the temperature is between 46 and 74 degrees Fahrenheit, and the red LED is activated when the temperature is above 74 degrees Fahrenheit. There is a yellow LED that will turn on when the humidity value is above 50, and there is a white LED that will turn on when the humidity value is below 50.

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 example assumes the sensor to be plugged into CONN2
#define DHTPIN 2     // 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 = 2102726;
const char * myWriteAPIKey = "T4G4E2JWC7JDNIPM";

int LEDpin = D7;
int LEDGREEN = D3;


void setup() {
   
    ThingSpeak.begin(client);
   
        pinMode(D2, OUTPUT);
        pinMode(LEDpin, OUTPUT);
        pinMode(LEDGREEN,OUTPUT);
       
        dht.begin();
        Particle.subscribe("LightBright", LightBright, MY_DEVICES);
        Particle.subscribe("LightNight", LightNight, MY_DEVICES);



     
}




void LightBright(const char *event, const char *data){
    digitalWrite(LEDGREEN,HIGH);
        digitalWrite(LEDpin,LOW);
      Particle.publish("TEST", PUBLIC);

}
void LightNight(const char *event, const char *data){
    digitalWrite(LEDpin,HIGH);
        digitalWrite(LEDGREEN,LOW);
}

   
void loop() {
    // Wait a few seconds between measurements.
    delay(1000);

    // Sensor readings may also be up to 2 seconds
    // Read temperature as Celsius
    float t = dht.getTempCelcius();
    // Read temperature as Farenheit
    float f = dht.getTempFarenheit();
   
      float h = dht.getHumidity();


    ThingSpeak.setField(1,f);
        ThingSpeak.setField(2,h);
       
    Serial.print(dht.getTempFarenheit());
        Serial.print(dht.getTempFarenheit());
        
    

    Serial.println("f");
      Serial.println(" %");
    ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);  
    delay(5000); // ThingSpeak will only accept updates every 15 seconds.
   
   
                    // numerical value it will notify the other argon
   if (f < 46.0) {
       Particle.publish("TempCold", String(f), PUBLIC);
   } else if (f >= 46.0 && f < 74.0) {
       Particle.publish("TempWarm", String(f), PUBLIC);
   } else if (f >= 74.0) {
       Particle.publish("TempHot", String(f), PUBLIC);
   }
   
   
  if (h < 50){
      Particle.publish("Dry", String(h), PUBLIC);
  } else if (h > 50){
     Particle.publish("Raining", String(h), PUBLIC);
  }
}

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


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

TCPClient client;


int LEDPIN3 = D3; 
int LEDPIN4 = D4; 
int LEDPIN5 = D5; 
int LEDPIN6 = D6; 
int LEDPIN7 = D7; 
int photoresistor = A0; 
int analogValue; 

unsigned long myChannelNumber = 2102726;
const char * myWriteAPIKey = "T4G4E2JWC7JDNIPM";


void setup() {
  Serial.begin(9600);
  pinMode(D3, OUTPUT); // Blue light
  pinMode(D4, OUTPUT); // Green light
  pinMode(D5, OUTPUT); // red light
  pinMode(D6, OUTPUT); // Yellow light
  pinMode(D7, OUTPUT); // White light
  pinMode(photoresistor, INPUT);
  Particle.connect();
  Particle.subscribe("TempHot", TempHot, MY_DEVICES);
  Particle.subscribe("TempWarm", TempWarm, MY_DEVICES);
  Particle.subscribe("TempCold", TempCold, MY_DEVICES);
  Particle.subscribe("Dry", Dry, MY_DEVICES);
  Particle.subscribe("Raining", Raining, MY_DEVICES);
ThingSpeak.begin(client);
}


void loop(){
      analogValue = analogRead(photoresistor);
      ThingSpeak.setField(3,analogValue);
      Serial.println(" Light");
    ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);  
    delay(1000); // ThingSpeak will only accept updates every 15 seconds.
      
}


void TempHot(const char *event, const char *data){
  if (analogValue > 50) {
    digitalWrite(LEDPIN5, HIGH); // Turn on red light
   digitalWrite(LEDPIN3, LOW);
   digitalWrite(LEDPIN4, LOW);
   Particle.publish("LightBright", PUBLIC);
} else if  (analogValue < 50){
 digitalWrite(LEDPIN5, LOW); // Turn off red light
   digitalWrite(LEDPIN3, LOW);
   digitalWrite(LEDPIN4, LOW);
     Particle.publish("LightNight", PUBLIC);

}
}

void TempCold(const char *event, const char *data){
    if (analogValue > 50) {
     digitalWrite(LEDPIN3, HIGH); // Turn on blue light
    digitalWrite(LEDPIN4, LOW);
     digitalWrite(LEDPIN5, LOW);
        Particle.publish("LightBright", PUBLIC);
}
else if  (analogValue < 50){
 digitalWrite(LEDPIN5, LOW); // Turn off blue light
   digitalWrite(LEDPIN3, LOW);
   digitalWrite(LEDPIN4, LOW);
        Particle.publish("LightNight", PUBLIC);
}
}

void TempWarm(const char *event, const char *data){
    if (analogValue > 50) {
    digitalWrite(LEDPIN4, HIGH); // Turn on green light
    digitalWrite(LEDPIN3, LOW);
    digitalWrite(LEDPIN5, LOW);
       Particle.publish("LightBright", PUBLIC);
}
else if  (analogValue < 50){
 digitalWrite(LEDPIN5, LOW); // Turn off green light
   digitalWrite(LEDPIN3, LOW);
   digitalWrite(LEDPIN4, LOW);
        Particle.publish("LightNight", PUBLIC);
}
}

void Dry(const char *event, const char *data){
       if (analogValue > 50) {
      digitalWrite(LEDPIN7, HIGH); // Turn on white light
      digitalWrite(LEDPIN6, LOW);
}
else if  (analogValue < 50){
digitalWrite(LEDPIN7, LOW); // Turn off white light
      digitalWrite(LEDPIN6, LOW);
}
}
void Raining(const char *event, const char *data){
      if (analogValue > 50) {
    digitalWrite(LEDPIN6, HIGH); // Turn on yellow light
      digitalWrite(LEDPIN7, LOW);
}
else if  (analogValue < 50){
digitalWrite(LEDPIN7, LOW); // Turn off yellow light
      digitalWrite(LEDPIN6, LOW);
}
}

Credits

Alan Luecke

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Malcolm Blades

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Light Identified Temperature Detection

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Photo Resistor and LED Circuit

DHT11 Temperature and Humidity Circuit Diagram

Code

DHT11 Code

Photoresistor Code

Credits

Alan Luecke

Malcolm Blades

Comments

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Light Identified Temperature Detection

Light Identified Temperature Detection

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Photo Resistor and LED Circuit

DHT11 Temperature and Humidity Circuit Diagram

Code

DHT11 Code

Photoresistor Code

Credits

Alan Luecke

Malcolm Blades

Comments

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