DHT22 is there a better one

[Dentonknifeworks]

I have set up two DHT22's one to control the heater and the other to report temp/humidity inside the box.
I put the data from both in a database and graphed the results using node-red.

I am finding that the DHT22 reports bad numbers on a random but just about once a day bad results example humidity 499989.0.
Anyway is there a better solution for a sensor that you are useing?

Thanks
Brad

[jcauthen78]

I use the adafruit_bme280 (https://www.adafruit.com/product/2652). Had similar problems with the DHT22, so tried a few different options, but the BME280 seems to do what I want with the accuracy I want. I have it go to a CSV file then read the newest data in and overlay the data on my images. The Python library and example from Adafruit is pretty straight forward, and I love that this little thing runs with the STEMMA-QT connectors, so it's easy to connect, as well as chain other QT devices as well.

[Dentonknifeworks]

Can you point me to the Adafruit python library example?
I always seem to find the outdated ones then have to mess with it for hours to get it to work.
Thanks

[jcauthen78]

BME280- links below to Adafruit (just shortened)
Pinouts: Pinout & Wiring Info
Python library and examples: Python Stuff

The library works quite well, and the device gives some solid readings with very few erroneous readings (i haven't seen any bad readings in months). If you're semi-familiar with Python (which sounds like you may be in order to get your readings into your database), you should be able to work your way through the examples and intuit what does what - I used a lot of google & Stack Exchange for more learning. I'm definitely not a great coder, more like a hobbyist who tries all kinds of stuff. Give it a look through and see what you think - if ya have any troubles, you're welcome to ask and I'll do what i can to help walk ya through some of it.

[Dentonknifeworks]

I did find the same links. Funny thing when I soldered the header in I had somehow managed to solder the address jumper on the PCB.
This changed the address to 0x76 on the IC bus. All of the code is looking for 0x77.
Well, redfaced I opened that jumper then I was able to get things working. Now time to get it in a database and start plotting a graph for testing.
Thanks

[Alex-developer]

I have just got a few SHT31's to try. These have a PTFE membrane over the sensor opening so are apparently better sealed. According to the datasheet the are IP67 compliant but obviously the electronics are not !

I currently use bme280's as I have found them to be the most stable so far

In all of my code I average out the readings over a number of samples and throw away obvious error. I use the sensors to switch on heaters and the averaging tends to help prevent the heaters switching on and off when close to the dew point.

[jcauthen78]

I like the averaging of readings - i'm gonna have to research, test and toss something like that into my python script.

[Curtis2012]

Taking the median of a series of readings will eliminate outliers.