Filter out value 1 from the property AQI

[bieniu]

Is your feature request related to a problem? Please describe.
Currently, the value of the AQI attribute of air purifier in Home Assistant is sometimes set to 1 for a short period of time. The device display never shows these values.

Describe the solution you'd like
python-miio should filter out values <=1 from aqi property.

Device information:
If the enhancement is device-specific, please include also the following information.

• Name(s) of the device: Xiaomi Mi Air Purifier 3H
• Link:

Use miiocli device --ip <ip address> --token <token>.

• Model: zhimi.airpurifier.mb3
• Hardware version: esp32
• Firmware version: 2.1.8

Additional context
Add any other context or screenshots about the feature request here.

[syssi]

Could you increase the log level and provide some traffic? Does the device response contain aqi: 1 sometimes?

logger:
  default: warn
  logs:
    homeassistant.components.xiaomi_miio: debug
    miio: debug

[bieniu]

Sure, I'll provide the log.

[syssi]

In the mean time you could pipe the measurements through the statistics component:

https://www.home-assistant.io/integrations/statistics/

[bieniu]

That's exactly what I do 😁

[bieniu]

I can confirm, the device sends value 1 for aqi.

2021-02-01 12:22:08 DEBUG (SyncWorker_4) [miio.miioprotocol] miairpurifier.bieniu.lan:54321 (ts: 1970-01-02 13:26:43, id: 402) << {'id': 402, 'result': [{'did': 'power', 'siid': 2, 'piid': 2, 'code': 0, 'value': False}, {'did': 'fan_level', 'siid': 2, 'piid': 4, 'code': 0, 'value': 1}, {'did': 'mode', 'siid': 2, 'piid': 5, 'code': 0, 'value': 3}, {'did': 'humidity', 'siid': 3, 'piid': 7, 'code': 0, 'value': 32}, {'did': 'temperature', 'siid': 3, 'piid': 8, 'code': 0, 'value': 22.1}, {'did': 'aqi', 'siid': 3, 'piid': 6, 'code': 0, 'value': 30}, {'did': 'filter_life_remaining', 'siid': 4, 'piid': 3, 'code': 0, 'value': 99}, {'did': 'filter_hours_used', 'siid': 4, 'piid': 5, 'code': 0, 'value': 15}, {'did': 'buzzer', 'siid': 5, 'piid': 1, 'code': 0, 'value': False}, {'did': 'buzzer_volume', 'siid': 5, 'piid': 2, 'code': -4001}, {'did': 'led_brightness', 'siid': 6, 'piid': 1, 'code': 0, 'value': 0}, {'did': 'led', 'siid': 6, 'piid': 6, 'code': 0, 'value': True}, {'did': 'child_lock', 'siid': 7, 'piid': 1, 'code': 0, 'value': False}, {'did': 'favorite_level', 'siid': 10, 'piid': 10, 'code': 0, 'value': 14}, {'did': 'favorite_rpm', 'siid': 10, 'piid': 7, 'code': 0, 'value': 2150}], 'exe_time': 340}
2021-02-01 12:22:38 DEBUG (SyncWorker_2) [miio.miioprotocol] miairpurifier.bieniu.lan:54321 (ts: 1970-01-02 13:27:13, id: 404) << {'id': 404, 'result': [{'did': 'power', 'siid': 2, 'piid': 2, 'code': 0, 'value': False}, {'did': 'fan_level', 'siid': 2, 'piid': 4, 'code': 0, 'value': 1}, {'did': 'mode', 'siid': 2, 'piid': 5, 'code': 0, 'value': 3}, {'did': 'humidity', 'siid': 3, 'piid': 7, 'code': 0, 'value': 32}, {'did': 'temperature', 'siid': 3, 'piid': 8, 'code': 0, 'value': 22.1}, {'did': 'aqi', 'siid': 3, 'piid': 6, 'code': 0, 'value': 1}, {'did': 'filter_life_remaining', 'siid': 4, 'piid': 3, 'code': 0, 'value': 99}, {'did': 'filter_hours_used', 'siid': 4, 'piid': 5, 'code': 0, 'value': 15}, {'did': 'buzzer', 'siid': 5, 'piid': 1, 'code': 0, 'value': False}, {'did': 'buzzer_volume', 'siid': 5, 'piid': 2, 'code': -4001}, {'did': 'led_brightness', 'siid': 6, 'piid': 1, 'code': 0, 'value': 0}, {'did': 'led', 'siid': 6, 'piid': 6, 'code': 0, 'value': True}, {'did': 'child_lock', 'siid': 7, 'piid': 1, 'code': 0, 'value': False}, {'did': 'favorite_level', 'siid': 10, 'piid': 10, 'code': 0, 'value': 14}, {'did': 'favorite_rpm', 'siid': 10, 'piid': 7, 'code': 0, 'value': 2150}], 'exe_time': 210}
2021-02-01 12:23:08 DEBUG (SyncWorker_3) [miio.miioprotocol] miairpurifier.bieniu.lan:54321 (ts: 1970-01-02 13:27:43, id: 406) << {'id': 406, 'result': [{'did': 'power', 'siid': 2, 'piid': 2, 'code': 0, 'value': False}, {'did': 'fan_level', 'siid': 2, 'piid': 4, 'code': 0, 'value': 1}, {'did': 'mode', 'siid': 2, 'piid': 5, 'code': 0, 'value': 3}, {'did': 'humidity', 'siid': 3, 'piid': 7, 'code': 0, 'value': 32}, {'did': 'temperature', 'siid': 3, 'piid': 8, 'code': 0, 'value': 22.1}, {'did': 'aqi', 'siid': 3, 'piid': 6, 'code': 0, 'value': 30}, {'did': 'filter_life_remaining', 'siid': 4, 'piid': 3, 'code': 0, 'value': 99}, {'did': 'filter_hours_used', 'siid': 4, 'piid': 5, 'code': 0, 'value': 15}, {'did': 'buzzer', 'siid': 5, 'piid': 1, 'code': 0, 'value': False}, {'did': 'buzzer_volume', 'siid': 5, 'piid': 2, 'code': -4001}, {'did': 'led_brightness', 'siid': 6, 'piid': 1, 'code': 0, 'value': 0}, {'did': 'led', 'siid': 6, 'piid': 6, 'code': 0, 'value': True}, {'did': 'child_lock', 'siid': 7, 'piid': 1, 'code': 0, 'value': False}, {'did': 'favorite_level', 'siid': 10, 'piid': 10, 'code': 0, 'value': 14}, {'did': 'favorite_rpm', 'siid': 10, 'piid': 7, 'code': 0, 'value': 2150}], 'exe_time': 170}

[bieniu]

So maybe we can change this into this:

    @property
    def aqi(self) -> int:
        """Air quality index."""
        return max(self.data["aqi"], 2)

[syssi]

Hmm.. so the lower bound of the measurements would be 2 always.

[bieniu]

Yup. Do you have a better solution?

[syssi]

You could remember the last value(s). If it the previous value is near to 1 a AQI of 1 is a valid value. If the previous value is pretty high a AQI of 1 should be dropped / or the previous value should be reported again.

[rytilahti]

Maybe AQI = 1 is just in-band signaling for "unable to measure"? In that case, returning None would be the correct way (to let the downstreams also know that the measurement failed) instead of having a cache (which can be implemented by the downstream users themselves.

[bieniu]

If the previous value is pretty high a AQI of 1 should be dropped

So we can use somethig like this:

@property
def aqi(self) -> int:
    """Air quality index."""
    if not self._last_aqi_value:
        self._last_aqi_value = self.data["aqi"]
        return self.data["aqi"]

    if (
        self.data["aqi"] == 1
        and self._last_aqi_value != 0
        and (self._last_aqi_value - self.data["aqi"]) / self._last_aqi_value > 0.9
    ):
        return self._last_aqi_value

    self._last_aqi_value = self.data["aqi"]
    return self.data["aqi"]

Maybe AQI = 1 is just in-band signaling for "unable to measure"?

Can we check somewhere if this assumption is true?

[rytilahti]

Can we check somewhere if this assumption is true?

Not really, but assuming the app is not showing that (i.e., it considers it as invalid) and it is always exactly 1 on those cases, then it's a reasonable assumption.

In my opinion the library should be returning None for those to give the downstreams a chance to interpret it as they want to (instead of using a cached value, which may be even very old depending on how often one does updates).