How to integrate a Gas Meter into Home Assistant?

[lofty fjord]

I have a gas meter that is able to poll the meter reading value via BLE. I would like to create an integration for this.
What kind of entity/sensor should I present it to home assistant? In what unit?

I have figured out how to pull data with Python Bleak. Just need to integrate it into an integration.

[sacred lotus]

Not sure how this is a question we could answer. You likely want to expose details you think are important in a way that they are useful to you. The more details you can read directly from the meter the less templating you may need to do in homeassistant to further use those results.

[tawdry scroll]

Maybe as a reference: I have a HomeMatic gas counter that reports recent power and a full count in cubic meters, I have a template sensor that converts the cubic meters into kWh according to energy density and environmental correction factor as published by my gas provider.

If your BLE counter would only provide the cubic meter count, you would need to add a template sensor for the power sensor as well

[lofty fjord]

Hmm, it does not provide cubic meter but in CF, I assume that means cubic feet? The physical reading on the meter is like XXXX.XX [CF] where CF is printed after the number, something like the image I attached which I found online

[tawdry scroll]

really impossible to say with an image that may or may not be of your counter, you should check with your gas meter provider for details

[normal frost]

CF is indeed cubic feet, which is the standard in (sighs most of) the US.
You can either just read this directly as a volume or, as @tawdry scroll mentioned - you can then multiply that by the energy density of the gas (either pick a static value, or work out something more dynamic using environmental factors based on your location, or pull from your supplier or whatever)
If you go the route of a dynamic energy calculation, you want to keep an internal total and add the change*energy density to it rather than just multiplying the total volume or you'll see big consumption swings as the density changes through the year

[buoyant stream]

Note CF not to be confused with CCF, which I have personally seen more often than CF.

[fathom silo]

A lot of these meters have a magnet on the most granular wheel - so you should be able to read it with a hall effect sensor.

[lofty fjord]

it is already a smart meter, so this is not needed.

[wet gyro]

i read my water meter this way with an esp32 and https://github.com/tronikos/esphome-magnetometer-water-gas-meter

[slow bridge]

If you would share a Brand and Model, that would help a lot. If it is a kind of Smart Meter, and used in a commercial environment, then it likely will have an encryption which needs to be handled. So with Brand and Model you could help to narrow down what you really need to do. I have not read, that you managed to read it already. You need sensor, unit_of_measurement: ft³ device_class: gas state_class: total_increasing according this topic and comments: https://community.home-assistant.io/t/adding-gas-to-energy-dashboard-solved/334988/

[lofty fjord]

I am looking at https://developers.home-assistant.io/docs/core/entity/sensor/
and I am wondering if I should useSensorDeviceClass.GAS SensorDeviceClass.VOLUME or SensorDeviceClass.VOLUME_STORAGE(obviously not this, right? since it is not storing)

[slow bridge]

If you want to add it to your energy dashboard, I think that you need to use gas

[lofty fjord]

also, where can I see what data type does it accept?

[lofty fjord]

hmm, it does say Volume of gas. Gas consumption measured as energy in kWh instead of a volume should be classified as energy.
what does this mean exactly? I don't get what it is trying to say

[slow bridge]

When you are paying for your gas consumption, you are paying for the used amount of energy (kWh or kiloJoule), that is calculated from the measured amount of volume, which has passed through your meter, and it is multiplied by a factor, which defines how much kWh of energy is in 1 unit of volume. So, let's say, you have a remote reading meter on your gas meter, which supplies the amount of volume which you used per hour, and the supply company calculates the amount of energy used from that, and provides with that through an API, then you would use that value as kWh and would define as energy.

These factors usually are all the same for extended periods. Maybe change a little bit, because the gas is supplied from the same source.

Of course, you might have heard from older relatives, especially if you are from an Eastern European country, that the color of burnt gas is blue or yellow, and indicating that the gas which is supplied has different content (ratio of burnable gas and oxigen), and of course you are charged for the energy, but measured by the volume.... 😉

[lofty fjord]

right, but I am reading directly from the meter as Cubic Feet unit so I can use the .GAS instead of .VOLUME?

[slow bridge]

Yes, you should use .GAS

[lofty fjord]

do I return a float?

I think float is not accurate? like 0.1+0.2 == 0.3 will return false

>>> 0.1 + 0.2 == 0.3
False
>>> 0.1 + 0.2
0.30000000000000004

[slow bridge]

Does it really matter?

You are returning the value what the meter provides, right?

[lofty fjord]

maybe not but I just want to make sure what kind of variable it accepts

like the data type

[slow bridge]

I cannot really help with that.

[lofty fjord]

the meter provides the data as a byte that is human readable 😅

like if the meter reads as 123.45 cubic feet, it will return b'\x00\x01\x23\x45'

[slow bridge]

I assume that your meter is likely measuring down to two decimals.

[lofty fjord]

yes 2 decimals

it is a battery powered device with BLE attached to a dumb meter by the gas company

[slow bridge]

What device is it? And meter do you have?

[lofty fjord]

I have no idea as it is branded with the gas company name

I mean the BLE device

presumably a custom device I think

but the meter is a Zenner meter

[slow bridge]

Is it a G4S like on your picture?

[lofty fjord]

Zenner Atmos U6(V) Class 1.5

[slow bridge]

I would go with float, as at some stage you have to define decimals.

[lofty fjord]

right

still figuring out how to present it to home assistant

I just finished the BLE device selection based on the generic bt integration

I have no idea how to present an entity to home assistant yet, still looking into it

[slow bridge]

Like in this Chinese article? https://hk.on.cc/hk/bkn/cnt/news/20230117/bkn-20230117164641323-0117_00822_001.html

This one is better: https://today.line.me/hk/v2/article/YaO9mwM?imageSlideIndex=2

[lofty fjord]

looks like it

[slow bridge]

Those are cubic feet models.

On one of the pictures it is visible clearly the flow rate description.

"clearly"

[lofty fjord]

I did say cubic feet

[paper bane]

If you are in metro Atlanta area using Atlanta Gas Light, you can use a SDR USB doggie to receive the gas meter data from 915MHz. The rtl_433 addon and its discovery supports it right out of the box, though you will need to modify the Consumption entity by adding device class ("gas") and unit of measurement (CF). Let me know if you need more details.

It is updated every 2-9 minutes.

[wet gyro]

that addon pulls my water meter but not my eletric meter. that comes over with some encryption

[paper bane]

Right. Electric meter uses flexnet which is encrypted

[wet gyro]

i know nothing about it. so thats pretty locked down then? ill probably just get a clamp for the cable and track it that way if so.

[paper bane]

Yes afaik. Clamps is the way to go

[wet gyro]

i was looking at shelly. do you use something different?