Hello !

Why not using a chip like the ADP5588, "designed for QWERTY type phones that require a large keypad matrix" : http://www.analog.com/en/power-manag...s/product.html ?

It is one of the keyboard chips that already have a driver in the linux kernel, so using it should mean near plug and play capability, as the code is already present in the kernel, and would be far more efficient than python.

The problem I can see is that Jolla didn't say if the interrupt line will be availlable. If not, then we will need to poll the keyboard, which is a shame... I2C is already quite limited, so not having interrupt lines will make it even weakier.

Also, one thing to not forget :
Add a contact to detect if keyboard is out or not. The virtual keyboard should be deactivated if the hard keyboard is out, and orientation should be locked in landscape.

My 2 cents. Keep on, I will try to follow your work.