Laptop Keyboard Ribbon schematics: Where to find?

[vbrenny]

Gentlemen,


as I've mentioned on my New Member post, I have a special love for the HMB4434EB (LG R405).
It is the only laptop keyboard (apart from that Really Old Toshibas that were not even laptops) that gave me a pleasant typing feeling.


I have a spare one and would like to convert it to use as an external piece.
I did my research, but all I could find was the wiring sequence of the ribbon to the controller, and I need to know what kind of signal you get in each one in order to be able to build it. It does not have the same number of connections a desktop keyboard uses to connect its membrane to controller.
I have tried using a regular controller even with less connections, but all I was able to dump form the port was garbage.


Does anybody have any kind of schematics, not even from this same model needed, alone in that dark and cold place of the Hard Drive?


I will, obviously, share my progress here and probably create some kind of comprehensive guide if other would like to do the same.


Also, donations of unused membrane controllers, laptop keyboard parts and other resources are accepted, even non-fully working ones.

[Findecanor]

Look through the controller firmware projects on the site. There is one firmware that has a "learning mode". It emits the name of each key. You press the corresponding key and the controller learns the signals for that key. When you are done, it knows the entire matrix. Unfortunately, I don't remember the name for this firmware, but perhaps you could use this idea anyway.

[vbrenny]

Look through the controller firmware projects on the site. There is one firmware that has a "learning mode". It emits the name of each key. You press the corresponding key and the controller learns the signals for that key. When you are done, it knows the entire matrix. Unfortunately, I don't remember the name for this firmware, but perhaps you could use this idea anyway.

Thanks for the info.

But as I said, I tried connecting it to a regular controller. I think the only way to go with your idea would be to find a notebook controller (is there such a stand-alone device?) and run this on it. I mean, before I can correctly read from the keyboard in order to map the keys, I need the schematics to be able to wire it.

When I said 'garbage', I meant it. It was oscillating when I had a single key pressed on; a dump file would be inconsistent for the same amount of time of pressing the same key.