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Arduino is an open-source platform that enables us to quickly build electronics projects. It consists of both a physical Programmable Circuit Board (PCB) and a piece of software (an Integrated Development Environment (IDE)) that works on all known operating systems. We use the Arduino to develop a weather monitoring system based on temperature and humidity variables obtained from a DHT11 sensor. The system, when tested, was able to report if weather is Hot, Normal, or Cold based on the exact temperature and relative humidity within a 20meter area. We also demonstrate the recycling of plastic foam to be used as an insulator and casing for electronic components. Plastic foam, which is a waste material, greatly contributes to the Global Warming Potentials (GWP) when discarded improperly.

Components:

• Arduino UNO
• DHT Sensor
• LCD 16*2
• Jumper wires

Code:

#include <dht.h> 

#define dht_dpin A1 //no ; here. Set equal to channel sensor is ondht DHT;  

LiquidCrystal lcd(12, 11, 5, 4, 3, 2); 

void setup(){  

lcd.begin(16, 2); 

lcd.print("TEMP HUMIDITY"); 

Serial.begin(57600);  

} 

void loop()

{

 lcd.setCursor(1,3);

 DHT.read11(dht_dpin);  

//lcd.print(abs(moisture));  

//Serial.println(moisture);

lcd.print(round(DHT.temperature)); 

lcd.print("C  "); 

 lcd.print(round(DHT.humidity)); 

lcd.print("%   "); 

 }

Conclusions:

The Arduino IDE was used in developing the sketches that were uploaded as firmware into

the  microcontroller.  Thereafter,  the  system  could  work  without  the  user's  intervention.

Libraries are  required for a robust  firmware development using  Arduino. In this case,  we

used  the  ‘LiquidCrystal’  and  ‘dht’  libraries.  Next  we  set  the Arduino  pins  and  attached

them to the LCD for display. Arduino pins 9, 10, 4, 5, 6, 7 were attached to the RS, E, D4,

D5, D6, D7 pins respectively  on  the  LCD. The ‘pinMode’ of Arduino pin  12  was  set  as

INPUT. This  is  the pin that  reads  the numeric values  from the signal pin of  the DHT11

sensor. At least a second delay is required to get reliable readings from the DHT11 sensor.

However,  we  used three(3)  seconds  delay  to ensure  that  the previous  values  have been

displayed.  It  is  also  important  to  confirm that  the  temperate  and  humidity readings  are

within the acceptable range for the sensor. In this work the humidity range was between 20

- 90 relative humidity, while the temperature ranged between 0 - 500c. Once the read values

are within range.