I have two ceiling fans (Fanimation) that are controlled by a basic wall toggle on/off switch. They also have RF remotes to control the speed/light (when switch is toggled on).
I want to integrate these into HA to be able to control on/off, speed, light, and schedule it. But I also want to keep the switch and convert to a smart switch (similar to a smart light switch), so that guests can still manually turn it on/off.
I have found guides to fully convert fans into HA but haven’t found any that allow it to still have a (smart) switch.
The best I’ve found is Caseta, but per Lutron, the whole fan would need to be rewired since Caseta won’t natively work with fans that have an RF remote control.
I’m not sure that my response is fully helpful for you. I have 4 ceiling fans that have lights included. Originally they came with RF remotes but during the installation we did not include the remote modules and discarded the remotes.
We have wiring (1 neutral, 1 line and 2 loads) going to the wall where we use 2 smart (ZWave) switches, one for fan and one for light. In some cases we had to cut the wall to add a second switch box. The fan switches are 3 speed from Jasco and the light switches are dimmers (all Zwave).
All these are entirely included in my HA with automations etc.
Fans can be tough to integrate because they often have very specific wiring or speed controls making smart (fan) switches a hassle to source. The above suggestion, for example, only works if there are separate load wires running from your switch to your fan for lighting and speed.
If your fan can be controlled with 433Mhz RF, you might want to consider using a RF bridge (e.g. Sonoff) to send the fan commands from HA. Then you can wire a small monitoring module (e.g. Shelly 1PM) into the electrical box behind the existing dumb switch. The module detects when the switch gets toggled by someone and notifies HA, which in turn sends commands to the RF bridge. The module can also measure power usage to help HA determine the fan’s speed/lighting state. There’s a bit of templating and automation code to get it all working, but it’s fairly non-intrusive, and would cost under $30. For a more robust (but advanced) solution, I would flash these devices with an open-source OS like Tasmota so they work cloud-free and direct, even when HA is offline.
According to the tech specs it uses an infrared, not RF, remote, so you can use a Broadlink or similar to learn the codes and control it. Alternatively that fan also has an optional wifi module and official HA integration. Definitely search the forums for BAF Haiku for examples of how other people set theirs up.
You could install a Shelly 1pm gen3 in the switch wall-box to function as a sensor. It can measure the power used by the fan and can detect when someone toggles the (dumb) switch. You could alternatively use a smart switch with “detached” or “smart bulb” mode that keeps power to the fan while sending only button-press events to HA when pressed.
You would need to write YAML configs in HA to send control codes to the broadlink (which actuates the physical fan with IR like a smart remote) or to the native Haiku wifi module.