debian_desktop icon indicating copy to clipboard operation
debian_desktop copied to clipboard

[PBP] LCTRL+LSHIFT+TAB does not work

Open samueldr opened this issue 5 years ago • 2 comments

This might be a keyboard firmware issue, or a matrix rollover issue with the keyboard.

This was verified in X11 using xev, once CTRL and SHIFT (on the left side of the keyboard) are held, pressing TAB does nothing.

This might be an rollover issue just like holding G and H makes T, Y, V and B stop responding...

Though, now that I'm testing this more thoroughly... I'm pretty sure the rollover. There is a bunch of pairs of keys on the matrix, that when held, will cause issues. I think the matrix can be mapped due to those issues, and this would give us "bad pairs"...

  • Holding Q and A will make the two whole rows from Q to ], then A to # stop responding.
  • Holding \ and A will do the same for their rows (A to #, \ to /).
  • You can guess what holding Q and \ does, I believe.

samueldr avatar Nov 03 '19 23:11 samueldr

I'm still mapping things out, but on the ISO keyboard, Tab and L Shift share a column/row, which could cause this issue. The ANSI keyboard has a different matrix configuration where these keys aren't aligned like that, and I seem to be able to receive all of the events.

jackhumbert avatar Jan 22 '20 15:01 jackhumbert

Oh, I never updated this: LCTRL+LSHIFT+TAB has since been confirmed to work fine on the "ANSI" keyboard, so this points towards the matrix I think, too.

Thanks for the hard firmware work!

samueldr avatar Jan 22 '20 18:01 samueldr