- Mon Nov 16, 2015 5:19 pm
#34231
Sounds like a dumb question but there's a slight feeling of frustration attributed as I have spent hours trying to figure this out... hoping someone here can help.
I have being trying to get this code working with ESP2866 board in Arduino IDE and haven't had much luck with reading values from DHT11 module.
It gives "Failed to read from DHT sensor!" .
I modified the "if condition" to see if it is specific to h,t or f and it fails on all of them.
Further, I decided to test if the sensor is working by uploading the code to my Arduino pro mini and it worked (on Digital pins), so I am so confused. For the ESP8266 I tested with pin 3 and 4, which are GPIO0 and GPIO02 respectively.. and I just can't get any values out of the sensor.
I have attached a picture of my setup. The sensor is connected to 5v, whilst the ESP module is connected to 3.3v. GPIO0 is connected to the data pin of the sensor.
This DHT11 module does not require resistors as it's built into it.
Any thoughts please?
DHT11 Module from ebay: http://www.ebay.co.uk/itm/351275013197? ... EBIDX%3AIT
I have being trying to get this code working with ESP2866 board in Arduino IDE and haven't had much luck with reading values from DHT11 module.
It gives "Failed to read from DHT sensor!" .
I modified the "if condition" to see if it is specific to h,t or f and it fails on all of them.
Further, I decided to test if the sensor is working by uploading the code to my Arduino pro mini and it worked (on Digital pins), so I am so confused. For the ESP8266 I tested with pin 3 and 4, which are GPIO0 and GPIO02 respectively.. and I just can't get any values out of the sensor.
I have attached a picture of my setup. The sensor is connected to 5v, whilst the ESP module is connected to 3.3v. GPIO0 is connected to the data pin of the sensor.
This DHT11 module does not require resistors as it's built into it.
Any thoughts please?
Code: Select all
// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain
#include "DHT.h"
#define DHTPIN 3 // what digital pin we're connected to
// 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("DHTxx test!");
dht.begin();
}
void loop() {
// Wait a few seconds between measurements.
delay(2000);
// 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) || isnan(f)) {
Serial.println("Failed to read from DHT sensor!");
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);
Serial.print("Humidity: ");
Serial.print(h);
Serial.print(" %\t");
Serial.print("Temperature: ");
Serial.print(t);
Serial.print(" *C ");
Serial.print(f);
Serial.print(" *F\t");
Serial.print("Heat index: ");
Serial.print(hic);
Serial.print(" *C ");
Serial.print(hif);
Serial.println(" *F");
}DHT11 Module from ebay: http://www.ebay.co.uk/itm/351275013197? ... EBIDX%3AIT
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