This is my analysis of the DHT22 and DHT11 temp/humidity sensors. Hopefully this proves useful for anyone else wondering about the difference.
I’m looking to monitor air quality in my home. Ideally each room so my goal is to keep the cost of each monitor as low as possible. I bought one of each of the DHT22 and DHT11 to compare hoping the DHT11 would be good enough because it’s only $5 compared to the DHT22 at $12.
I set up a small test with two spark cores and a sensor on each. They’re both sitting right next to each other on a table in my living room. It’s been going for about 24hrs at time of posting this.
Here’s the data. It’s still sampling every 5 minutes.
The 11 seems to track alright for temperature compared to the 22, but it’s clear the 22 is far more sensitive.
As for humidity, the 11 seems terrible compared. Not only does it not adjust well but it’s off by up to 5%RH at times.
Now I don’t have a 3rd trusted device for a control but looking at this data it seems the DHT11 simply isn’t sensitive to fluctuations you get in a typical home.
My decision is made. DHT22 is the way to go for my application.
@kareem613 i am also useing DHT11 my decision is same with you DHT11 isn’t sensitive will replace with DHT22 . By the way can you share your web aplication? i need this kind of web interface…
Here is a very accurate Temp and Humidity Sensor for $10. I paid $40 for this a Adafruit.
Nice summary, @kareem613.
Like @Yasin, I’ll also chime in with a request for more details on the web interface details and the server-side implementation.
Do you have that sensor working on a spark core?
As for the web app, I was thinking of opening it up for others to use.
In the mean time, interested in a test drive?
@kareem613 yes i am interesting with test drive. I think it will be nice .
I just saw that. I might try it out. The DHT22 with wires seems like better packaging though.
Yes you are right but SHT15 is really very sensitive.