Negative offset humidity greater than -10

Devices & Integrations Connected Things
1

hi is it possible to be able to change the negative humidity greater than -10
i have a sonoff snzb02
using the smartthings driver for ZigBee sensor devices ,
thanks
martin

2

Not really, because it’s kind of hard-coded and changing these defaults in the driver is a PITA.

You can try this driver and hope it works differently:

At least for humidity, the range -10 to +10 is a bit small, @nayelyz . Going to create an issue later today.

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3

Hi, @Andreas_Roedl. This is the issue you opened, right?

1 Like
4

I know it’s not the right place, but st.lib is dead.

And from what I could see, it’s not even in the lua libs, but in the firmware.

Could be wrong, though.

5

ah no problem, I was just making sure to send it to the team since it has more details about the changes you need.

It is a change in the standard preferences defined by SmartThings, you can see their configuration using this CLI command

smartthings devicepreferences tempOffset

2 Likes
6

@Andreas_Roedl, @montyfert

Can you confirm if the change you require is increasing the range from -20 to 20?

7

We can’t test it because it’s hard-coded somewhere.

All I can find…

aroedl@hydra ~/devel/ST/lua_libs-api_v11 $ grep -ir tempOffset *
integration_test/utils.lua:  tempOffset={
integration_test/utils.lua:    title="TempOffset",

… is this:

-- TODO: is there a way to handle this that isn't hardcoded?
-- TODO: handle this at the same time we are handling capability defs after
--       inventory is added
local canonical_preference_definitions = {
  humidityOffset = {
    title = "Humidity Offset",
    description = "Enter a percentage to adjust the humidity.",
    preferenceType = "integer",
    definition = {
      minimum = -10,
      maximum = 10,
      default = 0
    }
  },

[...]

  tempOffset={
    definition={
      default=0.0,
      maximum=10.0,
      minimum=-10.0,
    },
    description="Temperature Offset",
    preferenceType="number",
    title="TempOffset",
  },

We don’t have access to the firmware (or wherever it is defined) to make the necessary changes.

8

I know, I’m just trying to confirm the range that is useful for you to tell the engineer who can help us modify them to the new range.

1 Like
9

I see.

Hard to say. Range between -20 and 20 should be enough. Who knows if a wider range would have any side effects.

There are humidity sensors out there with a tolerance of 15% - like the IKEA VINDSTYRKA. For temperature sensors, +/-20 is plenty.

Humidity sensors in general are usually very inaccurate I’ve had three dht22 sitting on a table a foot apart with a 15% diff across the three.

https://www.reddit.com/r/homeassistant/comments/15vhfab/is_the_ikea_vindstyrkas_humidity_sensor_really/

20 is so much better than 10, 30 would be overkill.

1 Like
10

Is is really necessary to impose limits on the offsets? +/- 100 on the humidity maybe. But anything you specify for temperature is going to be dependent on whether it is interpreted in °C and °F anyway. As long as it doesn’t break the code what is the issue?

1 Like
11

that would be great thank you
martin