Why is DHT11 Sensor not giving correct readings on Arduino Mega?

Question

This is the outcome I am getting

#include <SimpleDHT.h>

// for DHT11,

// VCC: 5V or 3V

// GND: GND

// DATA: 2

int pinDHT11 = 2;

SimpleDHT11

dht11(pinDHT11);

void setup() {

Serial.begin(9600);

}

void loop() {

// start working...

Serial.println("=================================");

Serial.println("Sample DHT11...");

// read without samples.

byte temperature = 0;

byte humidity = 0;

int err = SimpleDHTErrSuccess;

if ((err = dht11.read(&temperature, &humidity, NULL)) != SimpleDHTErrSuccess) {

Serial.print("Read DHT11 failed, err="); Serial.print(SimpleDHTErrCode(err));

Serial.print(","); Serial.println(SimpleDHTErrDuration(err)); delay(1000);

return;

}

Serial.print("Sample OK: ");

Serial.print((int)temperature); Serial.print(" *C, ");

Serial.print((int)humidity); Serial.println(" H");

// DHT11 sampling rate is 1HZ.

delay(1500);

}

Answer 1

The reason the DHT11 would not work was because the sesnors were actualy faulty. There was nothing wrong with our code or wirings. We figured this out by trying a third DHT11 sensor which was brand new and just out of the packet. This time it worked and gave us accurate realistic readings.