Team 16:

•

Alex Yang

Published April 11, 2017 © GPL3+

Well House Temperature Manager

Monitors the temperature of the well house to prevent the well from freezing.

BeginnerFull instructions provided3 hours1,661

Things used in this project

Hardware components

Breadboard (generic)

This project can be completed with a single photon. However, this is a class project and using two photons is a requirement. I used a longer breadboard so as to fit both photons on the same breadboard.

Particle Photon

DHT11 Temperature & Humidity Sensor (4 pins)

The DHT11 may be slower than other available sensors but ease of use and the recommendations of friends led me to choose a DHT11 Breakout Board as my temperature monitor.

Wall Outlet

The wall outlet will be used to wire a relay without the need to worry about the house's wiring.

Relay (Single)

Power Cable

Software apps and online services

ThingSpeak API

Hand tools and fabrication machines

Voltimeter

Wire Stripper

Story

This IOT project was done for our Instrumentation class of Spring 2017 at UNC Charlotte. For this project, we are going to manage temperature and humidity readings inside a well house and operate a heat lamp to prevent water freezing within the pipes. The first photon will be collecting data through the temperature and humidity sensor and the second will monitor this data and trigger a relay to turn on a heat lamp if the temperature is too low. Particle publish and subscribe coding will be used to communicate the relevant temperature data each other. The first photon is also publishing temperature and humidity data to a ThingSpeak API to see the data change over time and see the effect of the heat lamp on the well temperature.

Brief Overview of the Well Monitor

PHOTON #1

The circuit shown in the diagram below is for a DHT11 sensor. We used a DHT11 breakout board to simplify wiring. This photon is also responsible for publishing data to the cloud as well as ThingSpeak. The Photon is powered by a spare phone charger we had laying around.

Photon 1 w/ DH11 Temperature/Humidity Sensor

The photon will be set on the floor near the pipes within the well house away from the heat lamp. This could be an issue because the IoT setup is right next to the overflow valve on the well. The chances of the overflow being needed are low but it is still something to think about. Too close to the heat lamp would cause incorrect readings and false powering down of the heat lamp. The photon was placed low on the ground because I didn't have anywhere else to put it in the well house. Due to low numbers of outlets, a power bar plugged into the wall outlet supplies power to all of the devices. Code for the first Photon is labeled as "Data Collection Photon" in the repository below.

PHOTON #2

The second photon is subscribed to the event data from the first photon. The temperature data is received as a string, and sent to the temperature handler function to translate the received string into an integer for comparison. Temperature data is in degrees Celsius. A relay will be operated by this second photon to turn on and off a heat lamp within the well house. If the temperature falls below 5 °C, the photon will activate the relay, turning on the heat lamp. Above 10 °C, the heat lamp is switched off. The gap is to allow the lamp to heat the room without turning off and on rapidly. These numbers may be changed in the code for different activation/deactivation settings. The relay is a normally closed relay and non-latching so that if the photon loses power or malfunctions the light will turn on. Code for the second Photon is labelled as "Switch Photon."

Photon 2

Assembly Closeup

The two photons is secured onto a single bread board. As stated above from photon 1 description, the setup was placed low on the ground and near the pipes. This will help the sensor measure the most accurate temperature reading of the pipe surroundings. but as mentioned before puts the assembly at a damage risk.

Complete bread board setup

Temperature and Humidity Monitors via ThingSpeak

The IoT device publishes data to the cloud every 30 minutes. Each graph on ThingSpeak is set to show 48 samples or a full days worth of temperature and humidity data at a time to show the data over the course of a full day

Temperature in °C every half hour, for the past 24 hours.

% Humidity every half hour, for the past 24 hours.

Code

// This #include statement was automatically added by the Particle IDE.
#include <Adafruit_DHT.h>
// DHT Pin Setting and DHT Type
#define DHTPIN 5
#define DHTTYPE DHT11
//Initialize the temperature and humidity variables as integers
int temperature;
int humidity;
//Set a constant string for the API node obtained from ThingSpeak
const String key = "5R0NW9ZKQAP0SO2M";
//Use the Library commands to confirm DHT Data pin and DHT Type (Type 11)
DHT dht(DHTPIN, DHTTYPE);
//Start the DHT protocols
void setup() {
  dht.begin();
}

void loop() {
  //Collects temperature data in Celsius, the fact that the Library spells it      "CelCius" is somewhat amusing
  temperature = dht.getTempCelcius();
  //Collects Humidity data as a percentage
  humidity = dht.getHumidity();
  //Publishes temperature and Humidity data to the cloud
  Particle.publish("tempC_clone222", String(temperature), PRIVATE);
  Particle.publish("hum_clone222", String(humidity), PRIVATE);
  //Publishes temperature and humidity to ThingSpeak 
  Particle.publish("thingSpeakWrite_All", "{ \"1\": \"" + String(temperature) + "\"," +
    "\"2\": \"" + String(humidity) + "\"," +
    //"\"3\": \"" + String(var2) + "\"," +
    //"\"4\": \"" + String(var3) + "\"," +
    //"\"5\": \"" + String(var4) + "\"," +
    "\"k\": \"" + key + "\" }", 60, PRIVATE);
    //Delays the loop for 1/2 hour or 1800 seconds
  delay(1800000);
}

//Sets pin D4 as the power toggle pin
const int tog = D4;
//initializes temperature
int temperature;

void setup() {
    pinMode(tog, OUTPUT);
    //The relay is wired as normally closed and is non-latching so that if the photon loses power the light will remain on, setting the pin value to high defaults the light to the off position by opening the relay circuit.
    digitalWrite(tog, HIGH);
}
void loop() {
    //Subscribes the device to the  temperature data coming from the first photon and send it to the temperature handler function
    Particle.subscribe("temperature", tempHandler, MY_DEVICES);
    //Compares the temperature value pulled from the cloud to the values set by the user to prevent the well from freezing
    if (temperature >= 10){
        //At a temperature greater than 10 deg C it opens the circuit and turns off the light
        digitalWrite(tog, HIGH);
    }
    else if (temperature <= 5){
        //At temperatures lower than 5 deg C it will close the circuit and turn on the light
        digitalWrite(tog, LOW);
    }
    else{
        //Reading any temperature in the "deadzone" between 5 and 10 deg C restarts the loop
    }
}
//Takes the string data retrieved from the cloud and converts it to an integer value for comparison
void tempHandler(const char *event, const char *data){
    //sets a new string, which i have defined as "pew" to take in the temperature data
    String pew = data;
    //Converts this new string "pew" into the previously defined integer "temperature"
    temperature = pew.toInt();
}

Credits

Daniel Douglas

1 project • 3 followers

Alex Yang

1 project • 0 followers

Thanks to Esther Jun Kim.

Well House Temperature Manager