`haco` Home Assistant Control Objects

haco is a Home Assistant Add-On, and associated Tasmota daemon written in Berry, to greatly simplify the process of exposing Home Assistant controls (e.g. Pull-down Lists, Number Sliders, Sensors, etc.) from a Tasmota device - and handling the communication between both sides.

Using haco to expose, for example, a "Restart Tasmota" button to Home Assistant is as simple as writing the following Python code:

from haco import Button, Tasmota

restart = Button('Restart Tasmota', icon='restart')


@restart.callback()
def ha(value) -> Tasmota[str, 'tasmota.cmd("restart 1")']:
    return value

A fully functional restart button will now appear associated with the device in Home Assistant:

Or, more practically, a cookbook pull-down menu, for a Tuya air fryer, might look like this:

OPTIONS = ['Default', 'Fries', 'Shrimp', 'Pizza', 'Chicken', 'Fish', 'Steak', 'Cake', 'Bacon', 'Preheat', 'Custom']

cookbook = Select('Cookbook', options=OPTIONS, icon='chef-hat')


@cookbook.callback()
def ha(value: str) -> Tasmota[int, tuya.send(4, 3)]:
    return OPTIONS.index(value)


@cookbook.callback(trigger=tuya.received(4, 3))
def tasmota(value: int):
    return OPTIONS[value]

Do I Need This? Can't I Do this with Native Tasmota?

You certainly can.

But in my experience, the process is so fiddly, error-prone and hard to maintain that it's enough to deter the casual user (as I am) entirely. Plus, sharing your configuration, once you've finally got it working, can mean complex step-by-step guides, setting up triggers, finding MAC addresses and topics (in Tasmota) - and numerous Blueprints, Helpers and Templates (on the Home Assistant side).

You can see how much work creating such guides involves by seeing how it was heroically undertaken by Blakadder, as compared with the full haco-based equivalent.

With haco, on the other hand, the thorny parts of the initial setup are abstracted away and your final configuration can often be shared via a single script. Below is a list of some of the tasks that haco handles for you:

Announcing the entity via MQTT to Home Assistant
Generating MQTT/HA-friendly unique IDs
Associating the entity with its parent device
Subscribing and publishing to the relevant MQTT topics
Managing the relevant Tasmota rules
Appropriate serialization of data
Translating Home Assistant messages to their to appropriate Berry data types, and vice versa

Pre-Release

⚠️ This library is currently in a pre-release state. The configuration format is likely to change, and only Sensor, Select, Button, Number, BinarySensor, Switch, Text, Update, Fan and Climate entities are currently implemented.

Installation

Installation involves installing two parts: the Tasmota daemon and the Home Assistant Add-On. Both are fairly simple.

Tasmota

I'd advise first using a guinea pig Tasmota device to get haco up and running. The device needs to have MQTT connected and be available to Home Assistant (i.e. showing up in the Devices section).

Once your test device is ready, with a recent (12.5+) version of Tasmota, simply paste the following into your Tasmota Berry Script Console:

{"download":tasmota.urlfetch('https://fmtr.link/haco/tapp','haco.tapp'), "restart":tasmota.cmd("restart 1")}

You should see output like {'restart': {'Restart': 'Restarting'}, 'download': 200} and the device will restart.

Once the device restarts, you should see the following among your Tasmota startup logs (in the regular console, not the Berry one):

HACO: The haco daemon has started. Hostname: tasmota-test, MAC: 04:74:77:9B:CB:CC. Listening for configuration...

Older Tasmota Versions

With older Tasmota versions, download the haco.tapp file on a desktop computer, upload it to your device and restart manually.

Home Assistant

You can now install the Home Assistant Add-On:

Once the Add-On is installed, click into its Configuration tab and you'll see a setting called assignments:

- config: null
  identifier: null

Assigning a configuration module to a device

Now we're ready to assign a configuration module to our Tasmota device. For now, we can use a built-in test module test. The identifer value should be the hostname (or MAC) of your Tasmota device. So for our example it should look like this:

- config: test
  identifier: tasmota-test # Hostname of Tasmota device

Saving the Configuration will restart the Add-On. After the restart, you should see the following in the Add-On logs:

Device "Tasmota Test Device" successfully configured. Hostname: tasmota-test MAC: 04:74:77:9B:CB:CC.

In Home Assistant, find the device in the Devices section. You should now see a test Select (pulldown) control called "Greeter".

Selecting the greetings from the pulldown, you should see them appear in your Tasmota Berry console, e.g.

haco says: Hello World!

This means haco is set up and working properly. Good! You can now use haco to assign configuration modules to your Tasmota devices.

Configuration Modules

Configuration modules are a little like drivers, that tell haco how to communicate with a Tasmota device, what controls to expose to Home Assistant, etc.

So far we've only used the test configuration module, that exposed the Greeter pulldown, but to control real-world devices, you'll need to assign them to a module written specifically for that device. There are currently two types of modules, Built-In and User-Defined.

Whichever type you use, assigning them to a device is done as we saw above.

Built-In Modules

haco ships with a small number of built-in configurations. These can be found in the configs directory in this repo. But in the likely event that your device hasn't already been added, you'll need to define your own.

ℹ️ The aim is to expand the number of built-in configurations over time. So if you define your own ( see below), please submit it to this repo as a Pull Request, or raise an Issue linking to your code!

Creating Your Own Configuration Module

General module structure

A configuration module is, ultimately, just a typical Python module. In this case, they contain definitions from one or more Control objects. Each control definition involves two things:

The control object assigned to a variable, e.g. temperature_sensor=Sensor(...)
Any required callback functions for the control, e.g. @temperature_sensor.callback(...)<function>

Location

User-Defined modules should be added to the /config/haco directory in Home Assistant, with a .py extension, e.g. /config/haco/my_config.py.

Defining controls

Here are a couple of simple examples to help get you started defining your own configuration module.

Tasmota-Only Controls

First, let's define a Tasmota-only sensor to report how much free memory there is on the Tasmota device. This sensor is "Tasmota-Only" as it only handles values sent from Tasmota (and sends nothing back from Home Assistant).

from haco import Sensor

memory = Sensor('Memory Free', icon='memory', uom=Sensor.UOM.DATA_KILOBYTES, uom_type=Sensor.UOM_TYPE.DATA_SIZE)


@memory.callback(trigger='Tele#Heap')
def tasmota(value: int):
    return value

Let's break this control definition down into the control object, the callback decorator, and the callback itself.

The control object

First we initialise a Sensor control object, assign it to a variable called memory, give it a relevant icon, unit of measure and type.

The callback decorator

The callback decorator @memory.callback(trigger='Tele#Heap') specifies a Tasmota trigger, the values from which will be sent to the callback function. This specific trigger, Tele#Heap, fires whenever telemetry data is returned from Tasmota and, specifically, returns the Heap field, which contains the free memory in kilobytes.

⚠️ Tasmota callbacks must have such a trigger specified in this decorator.

The callback

Note that the callback function is named tasmota. This name is important as it tells haco that this callback handles values from Tasmota.

The response from the trigger we specified in our callback decorator above gets fed into our callback as the value argument. The (optional) type annotation for the value argument (the int) tells haco what data type to expect from Tasmota, and type conversion gets done automatically.

The return value from the function is what will be returned to Home Assistant as the value for the sensor.

ℹ️ Note that our callback function does not actually do anything with our value other than return it. But if we wanted to (for example) convert the value from kilobytes to bytes, this is where we'd do it, with return value*1000.

ℹ️ You can find the list of available units of measure here and types here.

Home Assistant-Only Controls

Moving on to the opposite type of control, that is one that only handles values from Home Assistant. The Button control does exactly this, as it is triggered by being pressing in Home Assistant, but Tasmota returns nothing to acknowledge that press.

Here is how to define a Button control that, when pressed, restarts the Tasmota device.

from haco import Button, Tasmota

restart = Button('Restart Tasmota', icon='restart')


@restart.callback()
def ha(value) -> Tasmota[str, 'tasmota.cmd("restart 1")']:
    return value

In the case we define a Button control, and again use our decorator to add a callback to handle values from Home Assistant, which must therefore be named ha.

The `Tasmota` Type Annotation

The most notable difference with a Home Assistant (ha) callback is the Tasmota return type annotation. This takes two arguments, Tasmota[<type>,<berry_expression>]. The first argument is the type returned by the callback function, as per usual, and which again lets haco convert the return value accordingly.

The second argument is an expression that defines what to do on the Tasmota side when the button is pressed. In this case, this is just a Berry expression to restart Tasmota.

⚠️ Note that Home Assistant callbacks must have such a Tasmota type annotation for their return type.

ℹ️ In the example above, the value argument received and returned by our callback is not actually used by the Berry expression side. Home Assistant just sends a constant string (PRESS) when the button is pressed, so the actual content of the value argument is not important.

Two-Way Controls

Two-way controls need to handle values from both Home Assistant and from Tasmota, and hence need both the callbacks types - ha and tasmota we've seen above.

Here is an example two-way Select (pulldown menu) object. It allows setting the Tasmota WebLog console debugging level from Home Assistant, and also reflects any changes to that setting made on the Tasmota side.

from haco import Select, Tasmota

LOG_LEVELS = ["None", "Error", "Info", "Debug", "Debug More"]

weblog = Select('WebLog Level', icon='console', options=LOG_LEVELS)


@weblog.callback()
def ha(value) -> Tasmota[str, 'tasmota.cmd("WebLog "+value)']:
    return LOG_LEVELS.index(value)


@weblog.callback(trigger='WebLog')
def tasmota(value: int):
    return LOG_LEVELS[value]

The above is very similar to what we have already seen.

The ha callback takes friendly names (e.g. Error, Info) selected by the user in Home Assistant, and returns them as their corresponding number values (WebLog 1, WebLog2) used by Tasmota.

The tasmota callback, naturally enough, does the exact opposite, returning the string names to Home Assistant whenever the WebLog command is used on the Tasmota side.

Debugging Your Configuration

When you first assign a new configuration to a device, keep an eye on the Add-On logs for any errors. You'll see a typical Python stack trace if anything goes wrong.

⚠️ Each time you edit your configuration module (.py file), you'll need to restart the Add-On. Hot is reloading not yet supported.

Additional Capabilities

More complex device controls (e.g. Climate, Fan) have additional capabilities beyond a single value requiting Tasmota/Home Assistant callbacks. Adding callbacks for these extended capabilities is done similarly to the above, only the callbacks need to include the name of the capability. So if you want to add callbacks around setting the target_humidity of a Climate control, you'd need to call your callbacks target_humidity_tasmota and target_humidity_ha, etc.

A full schema of these names will appear in subsequent documentation. But you can find example implementations for most controls in the built-in development config.

Anway, if you get the names wrong, you'll see an error like this in your Add-On logs:

ValueError: Callback function name "set_mode_ha" is not valid for control "Climate". Must be one of: ['action_tasmota', 'current_humidity_tasmota', 'current_temperature_tasmota', 'mode_ha', 'mode_tasmota', 'preset_mode_ha', 'preset_mode_tasmota', 'swing_mode_ha', 'swing_mode_tasmota', 'target_humidity_ha', 'target_humidity_tasmota', 'target_temperature_ha', 'target_temperature_tasmota', 'temperature_high_ha', 'temperature_high_tasmota', 'temperature_low_ha', 'temperature_low_tasmota']

Additional Resources

Beyond these examples, when creating your own configuration, you'll probably find the built-in configurations (especially the development config) useful.

fmtr/haco

haco Home Assistant Control Objects