Cant parse DPT2ByteFloat -320.0

spali commented 5 years ago

Description of problem:

2019-05-11 19:03:44 ERROR (MainThread) [xknx.log] Error while syncing device: <ConversionError description="Cant parse DPT2ByteFloat" value="-320.0"/>

In my case it's and edge case with low prio. Because it's a new weather station, that I didn't fully setup yet. When the station has some error like no additional power source etc. it reports -320 °C as temperature. But maybe it leads to a bug in parsing floats in general? The strange thing is, the error displays the value correct... so why the error... is it out of a specification for temperature?

[ ] using xknx standalone
[X] using Home-Assistant knx plugin

Version information:

xknx / Home-Assistant release with the issue: 0.92.2
last working xknx / Home-Assistant release (if known): unknown

KNX installation:

Product: Griesser EMX-8 DPT: 9.001 Temperatur (°C) Monitor export: (first telegram is the read request from homeassistant, second is the answer)

<CommunicationLog xmlns="http://knx.org/xml/telegrams/01">
  <Telegram Timestamp="2019-05-11T17:03:44.7197551Z" Service="L_Data.ind" FrameFormat="CommonEmi" RawData="2900BCE0110A2C02030040A030" />
  <Telegram Timestamp="2019-05-11T17:03:44.6892171Z" Service="L_Data.ind" FrameFormat="CommonEmi" RawData="2900BCE010FA2C02010000" />
</CommunicationLog>

Problem-relevant xknx.yaml or configuration.yaml entries (fill out even if it seems unimportant):

knx:
  tunneling:
    host: !secret knx_gateway_ip
    port: 3671
    local_ip: !secret hass_instance_ip
sensor:
- platform: knx
  name: aussen_temperatur
  type: temperature
  address: 5/4/2

Traceback (if applicable): not available

farmio commented 5 years ago

Hello! You are exactly right. -320°C is out of the KNX specification of DPT 9.001 which would be: -273 °C ... 670 760 °C (and its also out of specification of laws of physics 🤓) If you can't disable this behaviour in the device application, you could bypass this error by using a general 2-byte float datatype

sensor:
- platform: knx
  name: aussen_temperatur
  type: 'DPT-9'
  address: '5/4/2'
  device_class: 'temperature'

I haven't tested setting device_class in the config, but it should work. This is for the little temperature sign in the visualization and may be needed for some components like HomeKit.

spali commented 5 years ago

Hello! You are exactly right. -320°C is out of the KNX specification of DPT 9.001 which would be: -273 °C ... 670 760 °C (and its also out of specification of laws of physics 🤓)

didn't even thought about that... you are absolutely right :see_no_evil:

If you can't disable this behaviour in the device application, you could bypass this error by using a general 2-byte float datatype
sensor:
- platform: knx
  name: aussen_temperatur
  type: 'DPT-9'
  address: '5/4/2'
  device_class: 'temperature'
I haven't tested setting device_class in the config, but it should work. This is for the little temperature sign in the visualization and may be needed for some components like HomeKit.

device_class is not allowed there, but with customization it's possible to set the device_class: 'temperature'

For anyone else that has this 1:1000000000 problem, the following results in a working (physical not possible) solution that looks exactly the same in home assistant 🦄

sensor:
- platform: knx
  name: aussen_temperatur
  type: 'DPT-9'
  address: 5/4/2

homeassistant:
  customize:
    sensor.aussen_temperatur:
      friendly_name: 'Aussen Temperatur'
      device_class: 'temperature'
      unit_of_measurement: '°C'

XKNX / xknx

Cant parse DPT2ByteFloat -320.0 #202