Bluetooth Binding - Emulate Bluetooth remote control?

I have a Xiaomi Projector, but Im sure this will apply to other makes/devices out there. It runs Android OS and has a Bluetooth remote control.

I have been using a Harmony Hub with this, as well as ADB commands to get what I want, however, there has always been a sticking point which is, if you power the device off fully (not sleep it) you can ONLY turn it back on with the power button on the remote control. The Harmony Hub cannot power back on from fully off, only from sleep and the Network is not available in this powered off state, so no ADB commands. Also, in this powered off state, the projector’s Bluetooth’s connection is either not visible to other devices or off (though I dont know how the remote powers it on, if Bluetooth is fully off).

Does anyone know if with something like the Bluetooth binding and perhaps with BlueZ (Linux Bluetooth stack), you can emulate an Android remote control (like you may get with any Android TV device)?

OR if its possible to capture a Bluetooth packet trace from a remote control and then somehow play it back from whatever you captured it on? e.g. my Openhab server.

Also, if it is possible, do you need a special Bluetooth Dongle (like a Bluegiga) or will it probably work with your computers onboard Bluetooth chip?

And if so, anyone any hints on how to do this?

Many thanks!

FYI, I have noticed these Bluetooth related projects, but they are currently beyond my understanding, but they may provide the solution somehow:

Based on my understanding something like this would require a new extension to the Bluetooth binding. I do see some extensions working like a remote (e.g. controlling AM43 rollershutter motors). But you’ll have to find or reverse engineer the messages and protocol used by the remotes. I’ll often search GitHub to see is someone has already done this work. Sometimes that can be used as is or used as a reference in implementing an OH add-on. But what you are looking for is a remote control for your specific device. You’ve unearthed some generic bluetooth libraries which enable the development of stuff that works with bluetooth but won’t tell you anything about the actual protocol.

Also be aware that many devices that have BT remotes (e.g. Gooble TV) have a pairing protocol that has to be implemented and performed before the device will listen to the commands from that device. Simply capturing and playing back the messages isn’t going to work.

Assuming it’s standard Bluetooth and the onboard BT supports the correct version of BT required by the device I see no reason why it wouldn’t work.

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Thanks for the reply, its roughly in line with where I had reached in my own thoughts/research.

I found people on some other forums looking into this for other home automation reasons, even specifically for the same device, though no one had the tech know how to implement anything, though I found the github links above and assumed they would help.

As for the commands/specification of the Bluetooth profile for the remote, Im pretty confident its based off this:

Though merging all this into a working solution, thats a whole different ballgame. Thought I would try here first and see if anyone has any knowledge/experience in reverse engineering these things and could offer any hints.

If nothing pops up here, I may try posting for help on those githubs and see if anyone there might be able to guide me in a direction.

Of course, if there is a relatively simple way to do it, Ill post an article on here so others can reverse engineer anything bluetooth.

Thanks

The power on/off button operates via IR technology, not Bluetooth. To make it work with Harmony, simply let it learn the IR button. The absence of a running system means no Bluetooth is active, making IR the primary method for turning the device on. To verify this, point the remote away and hide it from the projector; the power button should not trigger it. In contrast, other buttons relying on Bluetooth can still communicate with the projector after establishing a connection.

@Narendra_Raz Thanks for the reply, however the Xiaomi Laser projector I was looking at is 100% bluetooth operated:

As per the above image, there is no IR LED on the remote, it has the Bluetooth symbol on the rear and it will fully control the projector when the remote and yourself are wrapped up in a blanket with no line of sight to the projector.

The logitech Harmony does work with the projector if you set it as a Nvidia Shield, however, I was looking for a better solution as the Xiaomi Projector and its bluetooth on/off via the remote is the only thing I now keep my Harmony hub plugged in and powered on for.

Thanks