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DHT11  Sensor with LEDs and a Piezo Speaker

DHT11 Sensor with LEDs and a Piezo Speaker © CC BY-NC-ND

An Arduino Uno with DHT11 sensor module, three LEDs and a Piezo speaker.

  • 7,995 views
  • 4 comments
  • 21 respects

Components and supplies

Apps and online services

About this project

Hello! My name is Matei, I'm eleven years old and this is my fourth project. In this project we will use a DHT11 temperature and three LEDs that will show you that the temp. is too hot, perfect or too cold.

This is the DHT11:

These are the resistors and the LEDs:

And this is the Piezo speaker:

You will need these libraries:

If you like this project respect the project and follow me!

Donations: https://www.paypal.me/princematthew ( support is really appreciated😃)

Code

DHT11 with LEDs and piezo speakerC/C++
#include <Adafruit_Sensor.h>
#include <DHT.h>
int speakerPin = 9;
int length = 1;
#define DHTPIN 5
#define DHTTYPE DHT11
#define LED_TOO_COLD A0
#define LED_PERFECT A1
#define LED_TOO_HOT A2
DHT dht(DHTPIN, DHTTYPE);
void setup() {
  Serial.begin(9600);
  Serial.println("DHT11 test!");

  dht.begin();
}

void loop() {
  pinMode(speakerPin, OUTPUT);
  pinMode (A0 , OUTPUT);
  pinMode (A1 , OUTPUT);
  pinMode (A2 , OUTPUT);
  delay(2000);

  float h = dht.readHumidity();
  float t = dht.readTemperature();
  float f = dht.readTemperature(true);


  if (isnan(h) || isnan(t) || isnan(f)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.println(" *C ");
  if (t <= 20) {
    Serial.println("Too cold!");
    digitalWrite(A0, HIGH);
    digitalWrite(speakerPin, HIGH);
    delay (1000);
    digitalWrite(speakerPin, LOW);
    digitalWrite(A0, LOW);
  }
  if (20 < t < 27) {
    Serial.println("Perfect temperature!");
    digitalWrite(A1, HIGH);
    delay (2000);
    digitalWrite(A1, LOW);
  }
  if (t >= 29) {
    Serial.println("Too hot!");
    digitalWrite(A2, HIGH);
    digitalWrite(speakerPin, HIGH);
    delay (1000);
    digitalWrite(speakerPin, LOW);
    digitalWrite(A2, LOW);
  }

}

Schematics

DHT11
dht11_with_leds_and_piezo_speaker_JRpaa8ISfy.fzz

Comments

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