Hello everybody,
I have a problem communicating with my AM2302(humidity+temperature sensor). I use this code which is shown down here...
When I use this code with Arduino Uno which has a 16MHz crystal oscilator I have NO problem communicating with my AM2302 but when I use Panstamp I get the message "Failed to read from DHT sensor!"
Then I changed the third argument of "DHT dht(DHTPIN, DHTTYPE);" command which is by default 6 and is called "count" in the DHT library of adafruit. I do that beacause as the author says in comments you have to adjust the third value of the constructor regarding to the speed of your MCU and concidering that Panstamp has a 8MHz crystal I try values smaller than default value which is 6. But nothing happens for values from 0 to 6 and above! I still get the message "Failed to read from DHT sensor!".
Thank you in advance!
I have a problem communicating with my AM2302(humidity+temperature sensor). I use this code which is shown down here...
Code:
// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain
#include <DHT.h>
#define DHTPIN 7 // 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
// 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 for normal 16mhz Arduino
DHT dht(DHTPIN, DHTTYPE);
// NOTE: For working with a faster chip, like an Arduino Due or Teensy, you
// might need to increase the threshold for cycle counts considered a 1 or 0.
// You can do this by passing a 3rd parameter for this threshold. It's a bit
// of fiddling to find the right value, but in general the faster the CPU the
// higher the value. The default for a 16mhz AVR is a value of 6. For an
// Arduino Due that runs at 84mhz a value of 30 works.
// Example to initialize DHT sensor for Arduino Due:
//DHT dht(DHTPIN, DHTTYPE, 30);
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
float t = dht.readTemperature();
// Read temperature as Fahrenheit
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
// Must send in temp in Fahrenheit!
float hi = dht.computeHeatIndex(f, h);
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(hi);
Serial.println(" *F");
}When I use this code with Arduino Uno which has a 16MHz crystal oscilator I have NO problem communicating with my AM2302 but when I use Panstamp I get the message "Failed to read from DHT sensor!"
Then I changed the third argument of "DHT dht(DHTPIN, DHTTYPE);" command which is by default 6 and is called "count" in the DHT library of adafruit. I do that beacause as the author says in comments you have to adjust the third value of the constructor regarding to the speed of your MCU and concidering that Panstamp has a 8MHz crystal I try values smaller than default value which is 6. But nothing happens for values from 0 to 6 and above! I still get the message "Failed to read from DHT sensor!".
Thank you in advance!