Weather station with DHT11 Sensor and LCD 1602 display

1#include <dht_nonblocking.h>
2#define DHT_SENSOR_TYPE DHT_TYPE_11
3#include  <LiquidCrystal.h>
4
5static const int DHT_SENSOR_PIN = 2;
6DHT_nonblocking  dht_sensor( DHT_SENSOR_PIN, DHT_SENSOR_TYPE );
7
8// initialize the library  with the numbers of the interface pins
9LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
10
11/*
12  * Display fixe text .
13 */
14void setup( )
15{
16  lcd.begin(16, 2);
17  lcd.print(  "T = " );
18  lcd.setCursor(10, 0);
19  lcd.print( "deg. C" );
20  lcd.setCursor(0,  1);
21  lcd.print( "H = " );
22  lcd.setCursor(10, 1);
23  lcd.print( "%"  );
24}
25
26/*
27 * Poll for a measurement, keeping the state machine alive.  Returns
28 * true if a measurement is available.
29 */
30static bool measure_environment(  float *temperature, float *humidity )
31{
32  static unsigned long measurement_timestamp  = millis( );
33
34  /* Measure once every four seconds. */
35  if( millis( )  - measurement_timestamp > 3000ul )
36  {
37    if( dht_sensor.measure( temperature,  humidity ) == true )
38    {
39      measurement_timestamp = millis( );
40      return(  true );
41    }
42  }
43
44  return( false );
45}
46
47/*
48 * Main program  loop.
49 */
50void loop( )
51{
52  float temperature;
53  float humidity;
54
55  /* Measure temperature and humidity.  If the functions returns
56     true, then  a measurement is available. */
57  if( measure_environment( &temperature, &humidity  ) == true )
58  {
59   /*
60    * Display  changing text.
61    */
62    lcd.setCursor(4,  0);
63    lcd.print( temperature );
64    lcd.setCursor(4, 1);
65    lcd.print(  humidity );
66        
67  }
68}