Dallas temp, DS18S20, shows lower temperature after update

ESPHome
21

Update done :slight_smile:

22

I have 2 dallas sensors on one bus and no jumps in data for me either, now they are back working since updating to 2024.6.2. Not sure if it’s relevant (as below) but both mine end in 28 as well

23

I pulled the trigger and updated to 2024.6.2. My temps are also reporting fine. I’ve left the issue open for now in case it warrants further investigation. I don’t want to waste folks time. So I’m also happy to close it if needs be

24

It’s actually a DS18S20 sensor and the calculation is incorrect because of the datasheet and my mistake. This should fix it:

external_components:
  - source:
      type: git
      url: https://github.com/ssieb/esphome
      ref: onewire
    components: [ dallas_temp ]
    refresh: 1min
3 Likes
25

I updated 5 dallas sensors to 24.6.1 without any change in temp{all end in 28). Updating to 24.6.2 every one is getting random scratchpad checksum errors.

1 Like
26

Yes, there was an extra test I was trying for someone and it seems to cause that. I’ve removed that commit, so try again. (Assuming you are using my branch. The release one shouldn’t do that.)

1 Like
27

Unfortunately it was the production branch.

28

I installed 24.6.3, checksum errors are gone and temperature values are consistent.

29

I can confirm that 2024.6.3 seems to have fixed the problems. Now i get the same temperature reading after updating from 2024.5.5 to 2024.6.3

Also, yeah it was correct that my sensor is a DS18S20 and not a DS18B20 :slight_smile:

30

To avoid any future confusion, can you please correct your first post and subject line to reflect this?

31

Of course, done.

32

2024.6.3 have a fix fot it: [dallas_temp] fix ds18s20 temp calc by ssieb · Pull Request #6988 · esphome/esphome · GitHub
Probably now measurements must be Ok.