I search a way to control my CybovacE31 with a computer to integrate it into home automation system. I know that it is compatible with google home and Alexa but i don't find the protocol used. Do you have an idea how to do it? Thanks.
My vacuum : https://kyvol.com/products/cybovac-e31
Not really an answer, but got too long for a comment, so posting it here:
TL&DR; It's likely to use a proprietary protocol between the cloud and the device. It's not public and unlikely to become public.
In case of Alexa, you need to enable a proper skill, right? It's also likely to use a vendor specific mobile app for the initial discovery that uses either Wifi or BLE. Once discovered, the device gets wifi credentials and the skill sends discovery to Alexa, so it can be controlled.
So the registration flow looks like this: Vendor Mobile -> locate device -> get wifi credentials -> send wifi credential to device -> connect device to the cloud using user account.
To control device with Alexa the Amazon account should be linked with the vender user account and skill should be enabled.
The flow for a voice command looks something like this: Echo -> (internet) -> Alexa Cloud -> Skill -> (internet) -> Device.
Why I'm explaining all above? This flow is relatively complicated and it's not enough to know the protocol, but also device cloud should trust you, otherwise you can hack the device. Therefore to control the device, you'll need to be somehow registered and trusted. For most vendors creation of such a support doesn't worth it, therefore they don't publish the protocol.