Hello please help out an idiot, im very new to this and am trying to get the DHT11 temp/humidity sensor working, the sketch compiles and uploads fine but the serial data shows humidity -999% and temp -999 degrees, clearly this is because im wiring it onto my breadboard wrong.
Pin 1 goes to 5v.
pin 2 has a 10k resistor then to pin2 on the arduino.
pin 3 has nothing
pin 4 is to GND.
This is the tutorial im using, do I need another wire that goes on pin 2 to pin 1 after the resistor? It's confusing.
// 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");
}
}
// 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
Have you connected it this way, because you say that
Thanks the resistor is now sitting between 5v and pin 1
If it is all connected correctly and you are sure the library works ok, then maybe you need to check that the voltage is correct (5V) on the sensor with a multimeter. Next step is to try a different sensor
I used onre of the DHT libraries from the playground ant it worked real fine for me... was a DHT11 and I had to "Fudge' the measurement a little for calibration, matter of fact I have 3 of the sensors and all were within a half percent or so of each other and about 5% low over all, Bought a DHT22 (AM2302) because I didn't like the stated accuracy and humidity range. BUT the sketch and library I downloaded from the playground worked from the gate...
THanks I couldnt get it working, i guess ive got a duff arduino because I havent managed to get anything working on it. All lights come on fine but no readings from this or an ultrasonic sensor.
all pin out is okey.