MEGR 3171 Team 10: Dev Jha, James Warren, Carlos Rodriguez

Published April 26, 2021

Weather Monitoring System

A weather monitor system that uses sensors to show the temperature, humidity, and air quality.

IntermediateFull instructions provided526

Things used in this project

Hardware components

Particle Argon

DHT11 Temperature & Humidity Sensor (3 pins)

Seeed Studio Grove - Gas Sensor(MQ2)

Seeed Studio Grove - Air quality sensor v1.3

LDR, 5 Mohm

Resistor 1k ohm

Software apps and online services

ThingSpeak API

Particle Build Web IDE

Story

ABOUT

One thing that affects almost every person daily is the weather. Will it be sunny, what will the temperature be, will the wind pick up, etc.? These are questions the average person thinks about each morning when they wake up. With that being said, predicting the weather seems to be one of the most difficult things. Everyone can agree that there are multiple times where they look at their weather app and then the next day it could not be further from what it said the day before.

The problem we are trying to solve is plain and simple and helpful for everyone: have an accurate prediction of the weather. This is useful because the hope is for this to be more accurate than what the weather app can predict, or at least double check to ensure that it is giving accurate predictions. It is believed people would want it because it will help them have more confidence in weather predictions. If this system works, the consumer can either have confidence in it working correctly, or at least be able to compare the predictions with those on a weather app to check how accurate those are.

What makes this system so novel is how simple it is and user friendly it can be. It brings in something as confusing as weather predictions and puts in right in the palm of your hand. Whether it helps predict something different than what is shown other places (and is more accurate), or it just helps build confidence in what is being predicted, it just helps the consumer know what is being done, and makes it fun to be able to find out the results yourself.

Skills that have been learned throughout this process have made this process so much easier. We have learned more on the coding side, how to design the circuits/systems, and just more general knowledge of sensors and how they work. It has also been easier learning about the Particle argons and how they can connect to form different types of IOT’s from all around the world, and how they work.

CIRCUIT DESIGN PICTURES

VIDEO

LIVE DATA

1 / 2 • Temperature in Fahrenheit

Code

#include "Adafruit_DHT.h"

#define DHTPIN 2     // what pin we're connected to

#define DHTTYPE DHT11		// DHT 11 



DHT dht(DHTPIN, DHTTYPE);

SYSTEM_MODE(AUTOMATIC);

void setup() {
    pinMode(A0,INPUT); //LDR PIN
    pinMode(A1,INPUT); //MQ2 PIN
    pinMode(A2,INPUT); //MQ135 PIN
	Serial.begin(115200); 
	dht.begin();
}

void loop() {
    
    // Wait a few seconds between measurements.
    delay(2000);
    // very slow sensor)
	float h = dht.getHumidity();
    // Read temperature as Celsius
	float t = dht.getTempCelcius();
	
	//Get Light Level
	float LDR=analogRead(A0);
	//Read MQ2 Level
	float MQ2=analogRead(A1);
	//Read MQ135 Level
	float MQ135=analogRead(A2);
  
    // Check if any reads failed and exit early (to try again).
	// if (isnan(h) || isnan(t) || isnan(f)) {
	if (isnan(h)) {
		Serial.println("Failed to read from DHT sensor!");
		h=t=0;
	}
	
	//Convert the Sensor Data into JSON Response For  Webhooks which will send the data to ThingSpeak & Zapier for further process
	
	String Data="{\"field1\":\""+String(t)+"\","; //Temp
	Data+="\"field2\":\""+String(h)+"\","; //Humdity
	Data+="\"field3\":\""+String(LDR)+"\","; //LDR
	Data+="\"field4\":\""+String(MQ135)+"\","; //MQ135
	Data+="\"field5\":\""+String(MQ2)+"\"}"; //MQ2
	

	Particle.publish("WeatherData", Data, PUBLIC);
	
	Serial.print("Humid: "); 
	Serial.print(h);
	Serial.print("% - ");
	Serial.print("Temp: "); 
	Serial.print(t);
	Serial.println("*C");
	Serial.print("LDR: ");
	Serial.println(LDR);
	Serial.print("MQ2: ");
	Serial.println(MQ2);
	Serial.print("MQ135: ");
	Serial.println(MQ135);
	Serial.println(Time.timeStr());
	// Wait a few 30 seconds between measurements.
	delay(300000);
}

#include "Adafruit_DHT.h"

DHT::DHT(uint8_t pin, uint8_t type, uint8_t count) {
	_pin = pin;
	_type = type;
	_count = count;
	firstreading = true;
}

void DHT::begin(void) {
// set up the pins!
	pinMode(_pin, INPUT);
	pinSetFast(_pin);
	_lastreadtime = 0;
}

float DHT::readTemperature() {
	float f;

	if (read()) {
		switch (_type) {
			case DHT11:
				f = data[2];
				return f;
			case DHT22:
			case DHT21:
				f = data[2] & 0x7F;
				f *= 256;
				f += data[3];
				f /= 10;
				if (data[2] & 0x80)
					f *= -1;
				return f;
		}
	}
	return NAN;
}

float DHT::getHumidity() {
	return readHumidity();
}

float DHT::getTempCelcius() {
	return readTemperature();
}

float DHT::getTempFarenheit() {
	return convertCtoF(readTemperature());
}

float DHT::getTempKelvin() {
	return convertCtoK(readTemperature());
}

float DHT::getHeatIndex() {
	return convertFtoC(computeHeatIndex(convertCtoF(readTemperature()), readHumidity()));
}

float DHT::getDewPoint() {
	return computeDewPoint(readTemperature(), readHumidity());
}

float DHT::convertFtoC(float f) {
	return (f - 32) * 5 / 9;
}

float DHT::convertCtoF(float c) {
	return c * 9 / 5 + 32;
}

float DHT::convertCtoK(float c) {
	return c + 273.15;
}

float DHT::readHumidity(void) {
	float f;

	if (read()) {
		switch (_type) {
			case DHT11:
				f = data[0];
				return f;
			case DHT22:
			case DHT21:
				f = data[0];
				f *= 256;
				f += data[1];
				f /= 10;
				return f;
		}
	}
	return NAN;
}

float DHT::computeHeatIndex(float tempFahrenheit, float percentHumidity) {

	return -42.379 + 
		 2.04901523 * tempFahrenheit + 
		10.14333127 * percentHumidity +
		-0.22475541 * tempFahrenheit * percentHumidity +
		-0.00683783 * pow(tempFahrenheit, 2) +
		-0.05481717 * pow(percentHumidity, 2) + 
		 0.00122874 * pow(tempFahrenheit, 2) * percentHumidity + 
		 0.00085282 * tempFahrenheit * pow(percentHumidity, 2) +
		-0.00000199 * pow(tempFahrenheit, 2) * pow(percentHumidity, 2);
}

float DHT::computeDewPoint(float tempCelcius, float percentHumidity) {
	double a = 17.271;
	double b = 237.7;
	double tC = (a * (float) tempCelcius) / (b + (float) tempCelcius) + log( (float) percentHumidity / 100);
	double Td = (b * tC) / (a - tC);
	return Td;
}

boolean DHT::read(void) {
	uint8_t laststate = HIGH;
	uint8_t counter = 0;
	uint8_t j = 0, i;
	unsigned long currenttime;

// Check if sensor was read less than two seconds ago and return early
// to use last reading.
	currenttime = millis();
	if (currenttime < _lastreadtime) {
// ie there was a rollover
		_lastreadtime = 0;
	}
	if (!firstreading && ((currenttime - _lastreadtime) < 2000)) {
		return true; // return last correct measurement
//		delay(2000 - (currenttime - _lastreadtime));
	}
	firstreading = false;
/*
	Serial.print("Currtime: "); Serial.print(currenttime);
	Serial.print(" Lasttime: "); Serial.print(_lastreadtime);
*/
	_lastreadtime = millis();

	data[0] = data[1] = data[2] = data[3] = data[4] = 0;
  
// pull the pin high and wait 250 milliseconds
	pinSetFast(_pin);
	delay(250);

// now pull it low for ~20 milliseconds
	pinMode(_pin, OUTPUT);
	pinResetFast(_pin);
	delay(20);
	noInterrupts();
	pinSetFast(_pin);
	delayMicroseconds(40);
	pinMode(_pin, INPUT);

// read in timings
	for ( i=0; i< MAXTIMINGS; i++) {
		counter = 0;
		while (pinReadFast(_pin) == laststate) {
			counter++;
			delayMicroseconds(1);
			if (counter == 255) {
				break;
			}
		}
		laststate = pinReadFast(_pin);

		if (counter == 255) break;

// ignore first 3 transitions
		if ((i >= 4) && (i%2 == 0)) {
// shove each bit into the storage bytes
			data[j/8] <<= 1;
			if (counter > _count)
				data[j/8] |= 1;
			j++;
		}
	}

	interrupts();

/*
	Serial.println(j, DEC);
	Serial.print(data[0], HEX); Serial.print(", ");
	Serial.print(data[1], HEX); Serial.print(", ");
	Serial.print(data[2], HEX); Serial.print(", ");
	Serial.print(data[3], HEX); Serial.print(", ");
	Serial.print(data[4], HEX); Serial.print(" =? ");
	Serial.println(data[0] + data[1] + data[2] + data[3], HEX);
*/

// check we read 40 bits and that the checksum matches
	if ((j >= 40) && 
	   (data[4] == ((data[0] + data[1] + data[2] + data[3]) & 0xFF)) ) {
		return true;
	}
 
	return false;

}

#ifndef DHT_H
#define DHT_H

#include "application.h"
#include "math.h"

// how many timing transitions we need to keep track of. 2 * number bits + extra
#define MAXTIMINGS 85

#define DHT11 11
#define DHT22 22
#define DHT21 21
#define AM2301 21

class DHT {
	private:
		uint8_t data[6];
		uint8_t _pin, _type, _count;
		unsigned long _lastreadtime;
		boolean firstreading;
		float readTemperature();
		float convertFtoC(float);
		float convertCtoF(float);
		float convertCtoK(float);
		float computeHeatIndex(float tempFahrenheit, float percentHumidity);
		float computeDewPoint(float tempCelcius, float percentHumidity);
		float readHumidity(void);
		boolean read(void);

	public:
		DHT(uint8_t pin, uint8_t type, uint8_t count=6);
		void begin(void);
		float getHumidity();
		float getTempCelcius();
		float getTempFarenheit();
		float getTempKelvin();
		float getHeatIndex();
                float getDewPoint();

};
#endif

Weather Monitoring System

Things used in this project

Hardware components

Software apps and online services

Story

ABOUT

CIRCUIT DESIGN PICTURES

VIDEO

LIVE DATA

Schematics

Circuit Schematic

Code

Argon Weather Monitor Code

Argon Weather Monitor SubCode 1

Argon Weather Monitor SubCode 2

Credits

Dev Jha

James Warren

Carlos Rodriguez

Comments

Embed the widget on your own site

Weather Monitoring System

Weather Monitoring System

Things used in this project

Hardware components

Software apps and online services

Story

ABOUT

CIRCUIT DESIGN PICTURES

VIDEO

LIVE DATA

Schematics

Circuit Schematic

Code

Argon Weather Monitor Code

Argon Weather Monitor SubCode 1

Argon Weather Monitor SubCode 2

Credits

Dev Jha

James Warren

Carlos Rodriguez

Comments

Related tags