DHT11 sensor lab

main.cpp

#include <Arduino.h>
#include <Wire.h>

#include <dht_nonblocking.h>
#define DHT_SENSOR_TYPE DHT_TYPE_11
static const int DHT_SENSOR_PIN = 2;
DHT_nonblocking dht_sensor( DHT_SENSOR_PIN, DHT_SENSOR_TYPE );

#include <LiquidCrystal.h>
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);


// This function polls for a measurement and returns a boolean
// value of true if a measurement is available.
static bool measure_environment( float *temperature, float *humidity ) {

  static unsigned long measurement_timestamp = millis( );

  /* check once every four seconds. */
  if (millis( ) - measurement_timestamp > 3000ul) {
    if( dht_sensor.measure(temperature, humidity) == true ) {
      measurement_timestamp = millis();
      return true;
    }
  }

  return false;
}

void setup() {
  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("Temp     C      ");
  lcd.setCursor(0, 1);
  lcd.print("Humid    %      ");
}

void loop() {
  float temperature;
  float humidity;

  /* Measure temperature and humidity.  If the functions returns
     true, then a measurement is available. */
  if( measure_environment(&temperature, &humidity) == true) {
    lcd.setCursor(6, 0);
    lcd.print(temperature, 0);
    lcd.setCursor(6, 1);
    lcd.print(humidity, 0);
  }
}