Hi, I have directly connected a DHT22 to my Ardiuno M0 Pro, I have put a 10k Resistor across the Data & V+ of the sensor pinout. The data is connected to pin 5 and I have it connected to 3.3V output of Arduino.
I am just trying to see some readings from the sensor via the SerialUSB console. I have downloaded and unpacked the DHT libraries that I got on the Adafruit website/github. As far as I know I have these libraries in the right directory - C:\Program Files (x86)\Arduino\libraries\DHT...
I also have installed the Adafruit Unified Sensor library on the IDE.
I am trying to use the Tester program that is provided, this compiles ok but the SerialUSB printout prints: Failed to read from DHT sensor!
Failed to read from DHT sensor!
Failed to read from DHT sensor!
And so on...
I have tried another DHT22 sensor to no avail.
The only part of the code I have changed is the pin number and changed from Serial to SerialUSB.
Not sure if I have to change anything else? Or am I doing something really silly!
Here is the code:
// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain
#include "DHT.h"
#define DHTPIN 5 // 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() {
SerialUSB.begin(9600);
SerialUSB.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)) {
SerialUSB.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);
SerialUSB.print("Humidity: ");
SerialUSB.print(h);
SerialUSB.print(" %\t");
SerialUSB.print("Temperature: ");
SerialUSB.print(t);
SerialUSB.print(" *C ");
SerialUSB.print(f);
SerialUSB.print(" *F\t");
SerialUSB.print("Heat index: ");
SerialUSB.print(hic);
SerialUSB.print(" *C ");
SerialUSB.print(hif);
SerialUSB.println(" *F");
}