Testing DHT11 on arduino lily pad

Other Hardware Sensors
1

Hi,
I recently bought Arduino lily pad and DHT11 sensor.

i downloaded Arduino1.0v IDE and tested the Lilypad with blinking the led program and i was succeeded in that.

now i am trying to connect the DHT11 sensor and would like to test its working conditions.

Before posting this query i DHT11.Zip file from
http://arduino-info.wikispaces.com/page/diff/DHT11-Humidity-TempSensor/230407638

i included the library files to arduino1.0v IDE and executed the example program and uploaded to Lilypad .

A then i connected DHT11 sensor to Lilypad and opened the serial monitor window there i could notice the recorded readings but they where showing zero values.
Then i checked my sensor connections they where fine the gone through the example program and found that the pin which has been used to read the data was cleared but not used in the program here is that

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

#include "DHT.h"

#define DHTPIN 2     // what pin we're connected to

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

// Connect pin 1 (on the left) of the sensor to +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

DHT dht(DHTPIN, DHTTYPE);

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

void loop() {
  // 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();
  float t = dht.readTemperature();

  // check if returns are valid, if they are NaN (not a number) then something went wrong!
  if (isnan(t) || isnan(h)) {
    Serial.println("Failed to read from DHT");
  } else {
    Serial.print("Humidity: "); 
    Serial.print(h);
    Serial.print(" %\t");
    Serial.print("Temperature: "); 
    Serial.print(t);
    Serial.println(" *C");
  }
}

could any one link me with the correct code test my sensor status.

thanku

2

Someone ELSE just noticed that the DHT11 library from adafruit didn't work on their home-built Arduino if they changed it to run at 8MHz (like the lillypad). I looked at the library code and it looks like they use timing loops to measure pulse widths and compare the widths to a magic constant of 6 to determine if the pulse is a 1 or a 0. I think that value has to be adjusted downward for an 8 MHz processor because the timing loops will be running slower.

3

have you tried my DHT lib - http://arduino.cc/playground/Main/DHTLib -

It uses the micros() to measure the duration of pulses, not a counter so it should be CPUclock insensitive in theory ...

Please let me know if it works.