DHT11 vs DHT22 with Arduino

These temperature + humidity sensors are easy to connect to an Arduino, but which one should you use?

[walterdemoss]

I watch lots of Arduino videos. I am a High School Math and Science teacher. This was the best video I have seen in a long time. Short but loaded with details. Very well explained. Precise and to the point. Well done.

[LifeGeneralist]

Very useful video and I have no NEST to compare.

I too got both DHT11 and DHT22 sensors and found massive difference in the humidity.
DHT11 sensed 51 while DHT22 sensed 77.

[WideVisionMetalFab]

Thanks! I'd like to see more sensor/component reviews, if possible. It sure saves me a lot of time! :)

[AlienRelics]

Exactly the information I need. I'm building a multi-roll filament dryer. It will have two fans inside and sense temperature and humidity at two locations inside, plus the outside air temperature and humidity.

[markawbolton]

What the internal resistance of the cable would be significant compared to aprox 20k? Hence the on board pullup resistor?

[Terror-Gene]

Thanks for the vid, but a sample size of 1 barely makes a conclusion.

[rafaelcalvin]

can dht11 value represent as float like dht22? so the value have comma (, ) like dht 13, 7 etc

[fahnleindieselschweif]

I use only si7021. It uses I2C and is available as 3, 3V version without regulator and works down to 1, 9V

[VKRenato]

Thanks, excellent video. It I'll be interesting to compare bme280 sensor with dhtxx.

[LauwersFreddy]

When I piggyback a DHT22 sensor on the bottom of a 8266 D1 mini board to make it compact. The temperature displays 3-5°C higher immediately. Even with isolation foam between and the D1 mini not being warm at all, this stays the same. Once the sensor is 5cm away, all works fine. I’m wondering if this is some kind of interference. Now testing with the BME280 that seems a lot better and also has atmospheric pressure sensor. Thank you for making these videos.

[jsmythib]

I should have to calibrate every unique dht11 or dht22 I use. Wouldnt a simple offset in your code at your average target temp make it much more accurate?

[AlienRelics]

The issue with wire length and the pullup resistor is not wire resistance. You'd have to use a LOT of wire just to get one ohm. not enough to affect the reading. Especially since the output is digital.

The issue is noise. With a very high pullup resistor, like the internal pullup, it isn't very resistant to noise when compared to using a much lower resistance.

In any case, for that you should use twisted pair to reduce noise pickup.

[billykusuma]

Thanks it helps a lot!
btw did you know how much is the maximum range for both sensor? (Because i wanna build project temperature sensor for room)

[carlos.galhano]

Very good vídeo, thanks. I just beginning on Arduino. I ask you, if I need to save the data, not using a display but just save the Data to Open on a excell. Can you made a video about that. Thanks

[jedandecko]

Nice and simple :) gj. Can you check new ones from Bosch BME280 and BME680? I got some fun readings from those 2 especialy if i use them with esp wi-fi boards. Tnx

[dilrabink]

I used both Dht11 and dht22 sensors together, but dht11 sensor doesn't give the reading (I didn't use any resistor)
when used separately both sensors are working fine. Can u pls help me?

[julianbowen]

Comparing it to a nest sensor with unknown accuracy means you have 3 readings and cant say with certainty, which humidity reading is correct!

[AlienRelics]

If you don't need to measure humidity, a silicon diode will work as a temperature sensor. You'll just have to calibrate it, but that's not difficult.

[varunpoondi]

Hi guys, I have a problem with this line of code




void loop() {
int DHT11Check = DHT.read11(DHT11Pin);
// I am having a problem on this line
if (DHT11Check == 0){
Serial.print("Current Humidity = ");
Serial.print(DHT.humidity);
Serial.print("% ");
Serial.print("Current Temperature = ");

Serial.println("C ");
delay(3000);
}






It says that DHT wasn't declared in this scope
How do I resolve this problem? Thanks

Why keep working with the dht11/22, when you can get dht12/am2320 for the same prices or cheaper and you can choose between dht22onewire or standard I2C protocol