Assignment 6: Humidity Sensor and Fan

I decided to use smoothed humidity data from the DHT-22 sensor to turn a fan with DC motor on and off.

Code below combines DHT-22 data smoothing and motor response:

#include <DHT.h>
#include <DHT_U.h>
#define DHTPIN 2        // sensor DHT22 data connected to Arduino pin 2
#define DHTTYPE DHT22  // using sensor DHT22
DHT dht(DHTPIN, DHTTYPE);  //dht library 
int chk;
int humid; //stores humidity
int tempC; //stores temperature
int tempF; //stores temp in F
//data smoothing
const int numReadings = 10;
int tempReadings [numReadings];
int tempReadIndex = 0;
int tempTotal = 0;
int tempAverage = 0; 
int humReadings [numReadings];
int humReadIndex=0;
int humTotal = 0;
int humAverage = 0; 
int inputPin= 2; //put sensor pin here
//detecting sensor change
int last; 
//response to sensor change


//for fan and motor
int speedPin=5;
int dir1=4;
int dir2=3;
int mSpeed=0;

void setup() {
  // put your setup code here, to run once:
//pins for fan and motot
pinMode(speedPin,OUTPUT);
pinMode(dir1,OUTPUT);
pinMode(dir2,OUTPUT);


//dht sensor
dht.begin(); 

for (int thisReading = 0; thisReading < numReadings; thisReading++) {
    tempReadings[thisReading]= 0;
    humReadings[thisReading]=0;



Serial.begin(9600);

}
}

void loop() {
  
  humid=dht.readHumidity();
  tempC=dht.readTemperature();
  delay(2000);
  
  humTotal = humTotal - humReadings[humReadIndex];
  humReadings[humReadIndex] = humid;
  humTotal = humTotal + humReadings [humReadIndex];
  humReadIndex = humReadIndex + 1;
  if (humReadIndex >= numReadings) {
    humReadIndex=0;
  }
  humAverage = humTotal / numReadings;
  
  if (humAverage>=50)
{
  digitalWrite(dir1,HIGH);
  digitalWrite(dir2,LOW);
  analogWrite(speedPin,255);
}

if (humAverage<50)
{
  analogWrite(speedPin,0);
}
}

I finished writing the code and set up the sensor and motor. Before I could test, the wire on the motor broke off. I will need to see if I can reattach or replace with materials in the IDEATE room. I will come to office hours tomorrow to review.