Humidity Sensor-Controlled Bathroom Exhaust Fan

1#include <SimpleDHT.h>
2
3//Declaring digital pin no 2 as the dht11
4  data pin
5
6int pinDHT11 = 2;
7int DHTpower = 3;
8int Fan = 13;
9SimpleDHT11
10  dht11;
11
12void setup() {
13  pinMode(Fan, OUTPUT);
14  pinMode(DHTpower, OUTPUT);
15
16  digitalWrite(DHTpower, LOW);
17  digitalWrite(Fan, LOW);
18  Serial.begin(9600);
19   
20}
21
22void loop() {
23  delay(1000);
24  RHcheck();                        //check
25  Humidity Level
26  delay(15000);                     //wait 15sec
27  }
28
29
30void
31  RHcheck() {                    //Check Humidity Level Function
32  digitalWrite(DHTpower,
33  HIGH);     //On Humidity Sensor
34  delay(5000);
35  Serial.println("============
36  Check Humidity ===============");
37  delay(1000);
38  Serial.println("DHT11
39  readings...");
40   
41  byte temperature = 0;
42  byte humidity = 0;
43  int
44  err = SimpleDHTErrSuccess;
45
46  //This bit will tell our Arduino what to do
47  if there is some sort of an error at getting readings from our sensor
48  if ((err
49  = dht11.read(pinDHT11, &temperature, &humidity, NULL)) != SimpleDHTErrSuccess) {
50
51    Serial.print("No reading , err="); Serial.println(err);delay(1000);
52    return;
53
54  }
55  Serial.print("Readings: ");
56  Serial.print((int)temperature); Serial.print("
57  C, ");
58  Serial.print((int)humidity); Serial.println(" %");
59  delay(500);
60
61  if((int)humidity < 50){
62    digitalWrite(DHTpower, LOW);
63    delay(500);
64
65    Serial.println("Fan OFF");
66    delay(500);
67    digitalWrite(Fan, LOW);
68
69  }else{
70    if ((int)humidity > 58){
71      Serial.println("Humidity > 58%");
72
73      digitalWrite(DHTpower, LOW);
74      delay(500);
75      Serial.println("Fan
76  ON @ full speed");
77      delay(500);
78      digitalWrite(Fan, HIGH);
79    }else{
80
81      Serial.println("50% < Humidity < 58%");
82      digitalWrite(DHTpower,
83  LOW);
84      delay(500);
85      Serial.println("Fan ON @ low speed");
86
87      delay(500);
88      analogWrite(Fan, 150);
89    }
90  }
91 }
92

1#include <SimpleDHT.h>
2
3//Declaring digital pin no 2 as the dht11  data pin
4
5int pinDHT11 = 2;
6int DHTpower = 3;
7int Fan = 13;
8SimpleDHT11  dht11;
9
10void setup() {
11  pinMode(Fan, OUTPUT);
12  pinMode(DHTpower, OUTPUT);
13  digitalWrite(DHTpower, LOW);
14  digitalWrite(Fan, LOW);
15  Serial.begin(9600);   
16}
17
18void loop() {
19  delay(1000);
20  RHcheck();                        //check  Humidity Level
21  delay(15000);                     //wait 15sec
22  }
23
24
25void  RHcheck() {                    //Check Humidity Level Function
26  digitalWrite(DHTpower,  HIGH);     //On Humidity Sensor
27  delay(5000);
28  Serial.println("============  Check Humidity ===============");
29  delay(1000);
30  Serial.println("DHT11  readings...");
31   
32  byte temperature = 0;
33  byte humidity = 0;
34  int  err = SimpleDHTErrSuccess;
35
36  //This bit will tell our Arduino what to do  if there is some sort of an error at getting readings from our sensor
37  if ((err  = dht11.read(pinDHT11, &temperature, &humidity, NULL)) != SimpleDHTErrSuccess) {
38    Serial.print("No reading , err="); Serial.println(err);delay(1000);
39    return;
40  }
41  Serial.print("Readings: ");
42  Serial.print((int)temperature); Serial.print("  C, ");
43  Serial.print((int)humidity); Serial.println(" %");
44  delay(500);
45  if((int)humidity < 50){
46    digitalWrite(DHTpower, LOW);
47    delay(500);
48    Serial.println("Fan OFF");
49    delay(500);
50    digitalWrite(Fan, LOW);
51  }else{
52    if ((int)humidity > 58){
53      Serial.println("Humidity > 58%");
54      digitalWrite(DHTpower, LOW);
55      delay(500);
56      Serial.println("Fan  ON @ full speed");
57      delay(500);
58      digitalWrite(Fan, HIGH);
59    }else{
60      Serial.println("50% < Humidity < 58%");
61      digitalWrite(DHTpower,  LOW);
62      delay(500);
63      Serial.println("Fan ON @ low speed");
64      delay(500);
65      analogWrite(Fan, 150);
66    }
67  }
68 }
69