1-wire 20 sensor test

Hi all,

I though: let’s go 1-wire and see if all my 20 DS18B20 sensors are accurate.

I did add two more, not shown in the picture.

My problem is however that I don’t see all of the sensors update (60s) every time.

The result is quite interesting.
At 24°C there is a max 1°C range between the lowest and highest sensor.

Resolution is 12. Pull up resistor in the image is 1kOhm, but I also tried 4.7kOhm.
I guess its more a 1-wire problem than a ESPHOME problem. So therefore I posted this question here.

  - pin: GPIO23
    update_interval: 60s

  - platform: dallas
    address: 0x6a0000002034c028
    name: "${device_name} Temperature 1"

My other question is, how do I calibrate these sensors. ESPHome can have an offset per sensor. But a linear offset (possible) could be better? Should I lay down this array in the fridge, and in a 30degree warm room? I don’t have a perfect calibrated temperature sensor. We have like 10 different, cooking, weather station etc, but no two the same temperatures occur.

You could apply a filter per sensor (in esphome). But that will not solve the unreliability of these things. I found the DS18B20 which are waterpoof are more accurate.

And there is also a DSB18S20 which should be more accurate. Not sure if these work in esphome.