Skip to main content

Ejemplo 3a - Medición de temperatura y humedad usando el ESP32 con despliegue en un display LCD

Resumen​

Realizar una aplicación muestre la tempetatura y la humedad obtenida con un sensor DHT11 en un display LCD. Se recomienda que haga uso del puerto serial para hacer debug de la aplicación.

Hardware​

Componentes​

La siguiente tabla muestra los componentes principales del circuito a montar:

ComponentesCantidadObservaciones
ESP321
DHT11 Temperature and Humidity Module1Disponible en el kit Elegoo (datasheet)
LCD 1602 Module1Disponible en el kit Elegoo (datasheet)

Esquematico​

esquematico

Diagrama de conexión​

La conexión entre el sensor el ESP32 y los modulos de hardware externo se muestra a continuación:

conexion

Archivo Fritzing

El archivo Fritzing dh11_lcd-esp32.fzz del ejemplo se puede descargar del siguiente [link]

Software​

Librerias empleadas​

Se agregaron las siguientes librerias (En construcción)

Programa​

El programa codificado se muestra a continuación:

// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain

// REQUIRES the following Arduino libraries:
// - DHT Sensor Library: https://github.com/adafruit/DHT-sensor-library
// - Adafruit Unified Sensor Lib: https://github.com/adafruit/Adafruit_Sensor


#include <LiquidCrystal.h>
#include "DHT.h"

#define DHTPIN 19     // Digital pin connected to the DHT sensor

// Uncomment whatever type you're using!
#define DHTTYPE DHT11   // DHT 11
//#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V
// NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1
// to 3.3V instead of 5V!
// Connect pin 8 of the sensor to whatever your DHTPIN is
// Connect pin 3 (on the right) of the sensor to GROUND (if your sensor has 3 pins)
// Connect pin 4 (on the right) of the sensor to GROUND and leave the pin 3 EMPTY (if your sensor has 4 pins)
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor

// Initialize DHT sensor.
// Note that older versions of this library took an optional third parameter to
// tweak the timings for faster processors.  This parameter is no longer needed
// as the current DHT reading algorithm adjusts itself to work on faster procs.
DHT dht(DHTPIN, DHTTYPE);

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 22, en = 23, d4 = 4, d5 = 0, d6 = 2, d7 = 15;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
  Serial.begin(9600);
  Serial.println(F("DHTxx test!"));
  dht.begin();

  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("LCD Ready!");
}

void loop() {
  // Wait a few seconds between measurements.
  delay(1000);

  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 1 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature(); 
  // Check if any reads failed and exit early (to try again).
  
  // Print readings using the serial port
  if (isnan(h) || isnan(t)) {
    Serial.println(F("Failed to read from DHT sensor!"));
    return;
  }
  Serial.print(F("Humidity: "));
  Serial.print(h);
  Serial.print(F("%  Temperature: "));
  Serial.print(t);
  Serial.println(F("°C "));

  // Print readings using the lcd
  lcd.clear();  
  //Choosing the first line and row
  lcd.setCursor(0,0);
  //Typing Humedad:   to the first line starting from the first row
  lcd.print("Humedad: ");
  //Typing the humidity readings after "Humedad: "
  lcd.print(h);
  lcd.print("%");
  lcd.setCursor(0,1);
  //Typing Temperatura:   to the first line starting from the first row
  lcd.print("Temp: ");
  //Typing   the temperature readings after "Temperatura: " 
  lcd.print(t);
  lcd.print((char)223); // displaying degree symbol (°).
  lcd.print("C");
}

Test de la aplicación​

En construcción...

Simulación online

La simulación del programa descargado se encuentra en ...)

Referencias​