[BRLTTY] Help to create a new braille device

[Dave Mielke]

[quoted lines by Jagdish Panda on 2021/06/25 at 19:05 +0530]

>to reduce the power consumption, ultra low power proxy sensors are embedded on board which turns on the display cells when a finger is near by. So, the device gains longer battery life.

Two thoughts come to mind:

Yours will be, to my knowledge, the first braille device where a sighted user won't be able to just look at the braille display in order to read what's on it.

An interesting feature that you might consider adding, at some point, is an addition to the protocol so that the driver can inform the core as to where the user's fingers are. Brltty does support this as some of the HandyTech models, for example, have this feature.

>Also this is the sacrifice we are making to reduce the cost of the braille display by 10 times.

That's very significant! I rather suspect, actually, that it'll end up being more than 10 times because users often take time off from reading to think, to go do something else, etc.

>Regarding the drivers, Voyager EasyLink device interface has more
>similarities to our device. Only difference is that our device has 10
>braille display cells where as EasyLink 12 has 12 cells.

That isn't a problem as querying the display size is part of the protocol. The Voyager driver uses its serial protocol for Bluetooth so you can have a look at the getSerialCellCount() function.

And this reminds me of another of your questions: Use Bluetooth Classic, not BLE.

Also, please give your device a unique Bluetooth name prefix so that brltty's device autodetection can easily determine which driver to use. Of course, for testing, it probably makes the most sense to use the EasyLink's prefix (see bluetooth_names.c), but you should eventually have your own.

>So, can you please guide me on how to use Voyager protocol with Bluetooth and what data structures to send from the device and the format that it will receive from BRLTTY for displaying.

That's an open-ended question. May I suggest that you familiarize yourself with the Voyager driver's serial protocol and then ask whatever specific questions you have.

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