ESP8266 Community Forum

- Wed Nov 01, 2017 2:01 pm #71448 I have a simple thermo hygrometer set up in a safe that uses a DHT11 and an NodeMCU. I found that the unit was reporting spurious values so I added 2 more DHT11 modules. Two of these basically agree on humidity and 2 agree basically on temperature, but these are not the same 2 for both. I put an Acurite remote temperature sensor next to the setup and it reports a slightly different temperature.

I have decided that the DHT11 is poor quality (which I knew when I purchased them 5 years ago or so). I am now planning on updating to something better and am requesting advice on what would be the best bang for the buck as well as compatible with ESP and Arduino boards. The choices I've considered are: DHT22, SHT31, BME280, Si7021. I'm leaning toward BME280 but was hoping for opinions since the delivery will probably take a few weeks.

Tl:dr; DHT22, SHT31, BME280, Si7021...what would you go with for ESP and/or Arduino projects?

- Wed Nov 01, 2017 6:53 pm #71460 BME280 is excellent, not very expensive, small, and easy to use. Its temperature is affected by its own heat, so might not agree with another thermometer nearby.

Since you’re probably not concerned with instantaneous changes, or labarotory accuracy, you could just do some filtering and averaging with the sensor you’ve got, and discard obviously spurious readings.

- Wed Nov 01, 2017 9:07 pm #71462 Do you have a source that you'd recommend? I've been looking on eBay as I typically do but am having trouble sorting through the mislabeled BMP280 sensors and the ones where they are fake items (selling the sensor, but a fake flower for $0.01). I've read they should be around $2 but so far I'm only seeing $5-10. I was going to buy a few so the per unit price makes a bit of a difference.

- Thu Nov 02, 2017 2:31 am #71463 I’ve got no cheap source, I bought on Amazon.