Add sweep_frequency service to RemoteEntity

[felipediel]

Context

In the process of scanning commands from RF remotes, it's essential to first scan the frequency. Currently, both tasks are managed by the same service — learn_command — which presents usability challenges for learning RF commands due to the following reasons:

• Scanning the frequency is the most time-consuming step in the process, taking 5~10 seconds. Currently, users are required to scan the frequency repeatedly for each learned command, instead of performing it just once initially.
• The user should interact with the UI, not with the service. Present implementations involve users staying alert to notifications indicating when to initiate a long click (to sweep frequency) followed by a short click (to learn the command), which is not very user-friendly.

Proposal

A preferable approach involves separating these tasks into distinct services — one dedicated to identifying the frequency and another to learn the commands themselves. This separation of concerns offers several benefits, including:

• Users can sweep the frequency only once, separately.
• Components can leverage this to create better UIs and voice services. Learning can be divided into steps, showing appropriate messages that guide the user through the process eg. "Press and hold any button on the remote for 5 seconds" then "Press the power button" etc
• Better exception handling, informative error messages at each step.
• Users can create intents like "Alexa, what is the frequency of this remote?"

Impact

Only two integrations have implemented the learn_command service so far:

• broadink
• mysensors

The only one that supports learning RF commands is Broadlink, so it will be the only one impacted by this change.

Proof of Concept

home-assistant/core#115785
home-assistant/core#115791

[clockbrain]

I very much support this proposal. I had much difficulty in scanning my RF remote ceiling fan controllers though the HA UI remote learn service. Main problem was that my remotes are of the type where a long press (to keep transmitting for the frequency sweep) puts the remote into a different mode and the subsequent short press gets recorded as a different command to the one I was trying to record. I eventually gave up on using the HA UI learn approach and instead used the fixed frequency patch of the python-broadlink project to scan my remotes which worked much more reliably.

One thing I'd like to add is that I would like to see HA UI have the option of being able to manually specify the frequency instead of calling the sweep service. I know all my remotes are 433.92MHz so I see no need to sweep unless that is just a once-off and the frequency can be saved for many subsequent learn service calls.

[kobemtl]

You are the man! Just got the new Broadlink and the HA integration is way slower than the original app. This would be the solution! Thank you!

[CitizenRacer]

This would be so incredibly useful. Please add it!

[flequi19]

yes please!