Comments on: DHT11 vs DHT22 vs LM35 vs DS18B20 vs BME280 vs BMP180

By: Rod Lee

Rod Lee — Tue, 03 Sep 2024 10:13:22 +0000

Thanks very much for this excellent comparison. I’m always astonished at how you guys seem to figure out what I’m going to do next and have a tutorial on the subject ready and waiting!

By: paradug

paradug — Tue, 12 Dec 2023 14:14:39 +0000

In reply to Sara Santos. After reading this article, I would assume that the results from the LM34/35 sensors would be the most accurate. Is that a correct assumption? I also would be interested in an article about humidity sensors. I have several humidity sensors and the values always differ by a troubling amount. I would love to see an article on humidity data collection with some evaluation of accuracy.

By: Don Joe

Don Joe — Fri, 19 Aug 2022 03:59:55 +0000

Aren’t these results kinda useless without a control group? How do we know which ones are most accurate?

By: dave

dave — Tue, 26 Jul 2022 03:17:37 +0000

Thanks ! I have 24 hours of two BME280’s and the outputs are very close.
I also have two DS18B20’s, with the ‘waterproof’ metal cap. also very close.
about 6 degF different.
NodeRed and SQLite

suggestions is to do a long term reading.
#1) put the DS18B20 into higher resolution and run the test for a year.
I have heard some of the sensors drift long term.
#2) do the rolling 10 point average.

By: Sara Santos

Sara Santos — Thu, 06 Jan 2022 15:49:21 +0000

In reply to Brendan Davey. Yes, you're right.

By: Sara Santos

Sara Santos — Thu, 06 Jan 2022 15:22:48 +0000

In reply to Brendan Davey.

Yes. You are right.
I need to redo this experiment.
Regards,
Sara

By: Brendan Davey

Brendan Davey — Thu, 06 Jan 2022 07:59:20 +0000

In reply to Tachyon. NO, the DS18B20's were not tested correctly, the whole outcome is incorrect. The DS18B20's are accurate to 0.06deg not 0.5 as shown..... a retest is in order iMO.

By: Brendan Davey

Brendan Davey — Thu, 06 Jan 2022 07:57:42 +0000

In reply to Sara Santos. This sorta makes the whole article a bit 'meh' and a fail IMO since the DS18B20's work very well with high accuracy in 12 bit mode, and better than most of those tested. They are far cheaper and easier to use as well, I would use these over BMP280's anuy day due to their relability and robustness. I think you should retest and report the data IMO.

By: Tachyon

Tachyon — Sat, 10 Jul 2021 16:56:25 +0000

Great review thanks!

My takeaway is that the best choice for most applications would be to go with the BME280 but to do some calibration testing and find out exactly what the self heating level is for that specific BME280 in that particular application and apply that as an offset in software.
eg.
temp_offset=-1.5
room_temp=readSensor.temp(sensorID)+temp_offset

However, for limited GPIO configurations (eg using an ESP8266-01) then the DHT-22 seems like the big winner since it genuinely requires only one pin.

By: Andre

Andre — Thu, 06 May 2021 23:56:45 +0000

The DS18B20s are off by 2ºC on avg but their accuracy is +/-0.5ºC. Something smells fishy. So sad you dont have a calibrated one (or a hdc1080 for higher precision).

Great comparison nonetheless.
abraços