I am hoping to get a sonoff switch mqtt ‘state’ payload into a sensor that can be used.
This page should be the reference I need: MQTT Sensor - Home Assistant
But for those of us wishing to retrieve a number of attributes from the payload, all we get is this non-useful descrtiption:
json_attributes
(list | string)A list of keys to extract values from a JSON dictionary payload and then set as sensor attributes.
I have failed to find a single example of how to use this - and my trial and error has been 100 % error These features really need examples somewhere, don’t they? Is there another documentation resource that I am unaware of?
Anyway, the specifics - can anyone please explain how this should look?
Thanks Sthope - yes it is all I need in this specific case, to operate a light, and the link is useful.
But the Tasmota firmware does put out the payload I added, with the extra detail. In this case it would be useful to see if the VCC value started creeping - I bought and flashed a number of Sonoff devices from Aliexpress; these things are very cheap and (for all I know) a potential fire risk, if quality control wasn’t highest priority.
I would also greatly benefit from a sensor that collects all MQTT variables in other use-cases as well - but I cannot get the ‘json_attributes’ feature to work… hence the post.
I’m having the exact same issue with a MQTT sensor. I’ve attempted all of the permutations of ways to list the attributes within the json_attributes list, but the component will not parse them. My yaml for the component looks like:
- platform: mqtt
name: playroom motion
state_topic: 'home/downstairs/playroom/sensor/motion'
value_template: '{{ value_json.status }}'
payload_on: "MOTION"
payload_off: "NO MOTION"
device_class: motion
json_attributes:
noise
event_id
height
width
x
y
pixels
status
The value_template is parsing the json just fine, so I’m confident it is formatted correctly…it just seems to totally ignore json_attributes aspect. Unfortunately I can’t just dump the entire structure into the value_template
Okay…it looks like part of my issue is that I’m using a binary sensor instead of a sensor (which makes sense).
I just did it your way and now the status of the sensor is the json string, instead of it being parsed out as attributes. Not exactly what I was trying to acheive
Yes but I assumed (not fully tested yet) that any automation trigger or condition etc. could simply consist of a template that extracts the variable you wish to use. I’ll have a go soon and test that assumption.
OK I think JSON is handled a bit differently in templating.
entering {{ states.sensor.mqttjsontest }} yields: <template state sensor.mqttjsontest={'Time': '2018-02-11T07:41:02', 'Uptime': 15, 'Vcc': 3.463, 'POWER': 'ON', 'Wifi': {'AP': 1, 'SSId': 'Geogaddi', 'RSSI': 84, 'APMac': '00:11:32:45:90:1F'}}; friendly_name=mqttjsontest @ 2018-02-11T19:41:02.459049+13:00>
I am trying to find the way to properly treat the sensor output as JSON.
I found that within a template string you can do this: {% set value_json=states(‘sensor.mqttjsontest’) %}. After that, value_json looks like a proper json object. But I cannot figure out how to use that object.
in sensors.yaml (it’s not a binary sensor really )
My xiaomi Cube’s data for a rotate event is sent via statestream from my pi to my pc
this is the statestream mqtt topic #homeassistant/binary_sensor/cube_158d000117d706/event
This is the data that comes with it
#{“event_type”:“rotate”, “value”:"-23.5"}
So this is how I extract said data
I am sure they could, using a template in the automation trigger. In Keith’s example, the template to use would be like {{ states.sensor.hassio_cube_158d000117d706_event.attributes.value | float }}
automation:
trigger:
platform: numeric_state
entity_id: sensor.temperature
# Optional
value_template: '{{ state.attributes.battery }}'
# At least one of the following required
above: 17
below: 25
Why not just create multiple MQTT template sensors? I’m doing something like this (from a package definition). Sorry for the YAML anchor stuff which might make this a little obfuscated, but I think you’ll get the idea.
Simply, I define a bunch of different sensors. Each happens to subscribe to the same topic, and each selects a different part of the JSON payload. One advantage of this is that you don’t need to worry about attribute changes kicking off a state-change or not. Since each sensor is unique with only a single value, you can reliably use it in an automation based on the state being updated.
Well - initially I couldn’t get much sense from the sensor at all - even now, I suspect the format is bung (the JSON is hidden within a string). I gave up on it for now to be honest.
But also; if you could define a single sensor for each object, instead of 5 or 6 - then I think things would be a lot tidier. It’s fine if you only have several such devices, but I intend to have up to 15 of these things. In that scenario, 75 sensors might be excessive
These features really need examples somewhere, don’t they? Is there another documentation resource that I am unaware of?
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