Arduino Sensor DHT11 E Termistor NTC

[MicSG]

Olá.

Fiz um código para verificar temperatura ambiente. Para deixar a leitura mais precisa utilizei um DHT11 e um termistor NTC e com as leituras tirei a média de temperatura. Queria saber se eu tirando a média de temperatura ( Soma dos valores e divide por 2[nº de sensores] a a leitura fica realmente mais precisa ou se a leitura está completamente errada.Segue o código:

Nota: Utilizei como microcontrolador o Arduino UNO.

// 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 "DHT.h"

#define Vin 4.88 // define constante igual a 5.0
#define T0 298.15 // define constante igual a 298.15 Kelvin
#define Rt 10000 // Resistor do divisor de tensão
#define R0 10000 // Valor da resistencia inicial do NTC
#define T1 273.15 // [K] in datasheet 0º C
#define T2 373.15 // [K] in datasheet 100° C
#define RT1 35563 // [ohms] resistencia in T1
#define RT2 549 // [ohms] resistencia in T2
float beta = 0.0; // parametros iniciais [K]
float Rinf = 0.0; // parametros iniciais [ohm]
float TempKelvin = 0.0; // variable output
float TempCelsius = 0.0; // variable output
float Vout = 0.0; // Vout in A0
float Rout = 0.0; // Rout in A0

#define DHTPIN A1     // Digital pin connected to the DHT sensor
// Feather HUZZAH ESP8266 note: use pins 3, 4, 5, 12, 13 or 14 --
// Pin 15 can work but DHT must be disconnected during program upload.

// 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 2 of the sensor to whatever your DHTPIN is
// Connect pin 4 (on the right) of the sensor to GROUND
// 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);

void setup() {
  Serial.begin(9600);
  Serial.println(F("Testando DHT11"));
beta = (log(RT1 / RT2)) / ((1 / T1) - (1 / T2)); // calculo de beta
Rinf = R0 * exp(-beta / T0); // calculo de Rinf
  dht.begin();
  Serial.println("--------------");
  Serial.println(" ");
}

void loop() {
  // Wait a few seconds between measurements.
  delay(2000);
Vout = Vin * ((float)(analogRead(0)) / 1024.0); // calculo de V0 e leitura de A0
Rout = (Rt * Vout / (Vin - Vout)); // calculo de Rout
TempKelvin = (beta / log(Rout / Rinf)); // calculo da temp. em Kelvins
TempCelsius = TempKelvin - 273.15; // calculo da temp. em Celsius

  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  //float f = dht.readTemperature(true);

  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t) ) {
    Serial.println(F("Falha na leitura do sensor de temperatura DHT11"));
    return;
  }

  // Compute heat index in Fahrenheit (the default)
  //float hif = dht.computeHeatIndex(f, h);
  // Compute heat index in Celsius (isFahreheit = false)
  //float hic = dht.computeHeatIndex(t, h, false);
float mediaT = ((t+TempCelsius)/2);
  Serial.print(F("Humidity: "));
  Serial.println(h);
  Serial.print(F("Temperatura_DHT: "));
  Serial.println(t);
  Serial.print("Temperatura_NTC:"); // imprime no monitor serial
  Serial.println(TempCelsius); // imprime temperatura Celsius
  Serial.println("--------------");
  Serial.print("Média_Temperatura");
  Serial.println(mediaT);
  Serial.println("--------------");
  Serial.println(" ");
}

 

[.if]

A média é pra leitura ficar mais estável e não necessariamente mais precisa. Pra precisão você deve comparar com um termômetro padrão e fazer os ajustes se necessário.