Hi @BenHadman and @Blacksmithash.
I too have exactly the same problem with my DHT22 AM2302 sensor. Do any of you manage to fix this?
I tried my DHT11 sensor and had a similar problem. It only returned hum = 255% and temp = 0.
Regards
Hi again!
Changing the library from <Adafruit_DHT.h> to <Adafruit_DHT_Particle.h> fixed my problem with the DHT22 AM2302 sensor.
I hope this works for you as well!
Regards
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Neither of use could fix it!
I’ve opted to a new sensor type.
Got it to work! Thanks!
Weird - because I already tried that and the example code for it… I was about to try a different sensor.
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What did you do to fix? care to share the code and wiring?
Desperate to get this working.
I know the feeling. Code below. Note that I’ve incorporated the Udibots online trending app.
// This #include statement was automatically added by the Particle IDE.
#include <Ubidots.h>
// This #include statement was automatically added by the Particle IDE.
#include <blynk.h>
// This #include statement was automatically added by the Particle IDE.
#include <Adafruit_DHT_Particle.h>
// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain
#define DHTPIN D2 // Using D2 as the Data pin
#ifndef TOKEN
#define TOKEN " NOT ACTUALLY THE TOKEN " // Put here your Ubidots TOKEN
#endif
Ubidots ubidots(TOKEN, UBI_TCP); // Comment this line to use another protocol.
//Ubidots ubidots(TOKEN, UBI_HTTP); // Uncomment this line to use HTTP protocol.
//Ubidots ubidots(TOKEN, UBI_UDP); // Uncomment this line to use UDP protocol
// 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
// This is the authorisation code for sending data to Blynk. Don't show anyone.
char auth[] = " BLYNK AUTHORISATION CODE ";
// Tell the DHT code what pin and sensor we have
DHT dht(DHTPIN, DHTTYPE);
// Value for loop if you want to send particle to sleep
//int loopCount;
// Code for creating a virtual pin we're writing to
BLYNK_WRITE(V1)
{
int pinValue = param.asInt(); // assigning incoming value from pin V1 to a variable
// process received value
}
BLYNK_WRITE(V2)
{
int pinValue = param.asInt(); // assign incoming value from pin V2 to a variable
// process received value
}
void setup() {
Serial.begin(9600);
Serial.println("DHT22 test!");
Particle.publish("state", "DHT22 test start");
// Start the DHT sensor
dht.begin();
//loopCount = 0; THIS IS NOT REALLY REQUIRED BUT I'VE LEFT IT IN.
// Wait time for settling
delay(5000);
// Start Blynk code and give it authority
Blynk.begin(auth);
ubidots.setDebug(true); // Uncomment this line to print debug messages
}
void loop() {
// Wait a few seconds between measurements.
delay(2000);
Blynk.run();
// 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.getHumidity();
// Read temperature as Celsius
float t = dht.getTempCelcius();
// Check if any reads failed and exit early (to try again).
if (isnan(h) || isnan(t)) {
Serial.println("Failed to read from DHT sensor!");
return;
}
// Write values to virtual pins
Blynk.virtualWrite(V1, t);
Blynk.virtualWrite(V2, h);
ubidots.add("Variable_Name_One", t); // Change for your variable name.
ubidots.add("Variable_Name_Two", h);
bool bufferSent = false;
bufferSent = ubidots.send(); // Will send data to a device label that matches the device Id
if(bufferSent){
// Do something if values were sent properly
Serial.println("Values sent by the device");
}
// Write values to serial display
Serial.print("Humid: ");
Serial.print(h);
Serial.print("% - ");
Serial.print("Temp: ");
Serial.print(t);
Serial.print("*C ");
Serial.println(Time.timeStr());
String timeStamp = Time.timeStr();
Particle.publish("readings", String::format("{\"Hum(\%)\": %4.2f, \"Temp(°C)\": %4.2f}", h, t));
delay(10000);
/*loopCount++;
if(loopCount >= 6){
Particle.publish("state", "Going to sleep for 5 minutes");
delay(1000);
System.sleep(SLEEP_MODE_DEEP, 300);
}*/
}
Thanks so much for sharing, i got to work with your code!
Excellent.
The strange thing for me is that I had tried this example code before.
I had the same issue and the solution worked for me as well. Just changed the library to <Adafruit_DHT_Particle.h> and it worked.
Updated all my photons from 2.1.0 to 2.2.0 and now all my DHT22 sensors read 0 temp and 6553 humidity. I’m unable to roll back the firmware.
I have tired both libraries and nothing works now 
Just hosed my whole network of sensors
Any help?
Update: This is what solved my issue for now