I think I am on to something with this, specifically the Plus, for the purposes of this question, I am only interested in polling GPIO state from userland. Now I'm not quite enough of a wizard to figure out how the I hope this can be done without a kernel module since I'm not using it to do something ultra-privileged like powering on/off. Moving on from that then, it seems that I will want some sort of daemon to run that can poll GPIOs and trigger events based on them. Well, going through Linux is already the only way i know of to toggle the backlight. I wonder if there is some electrical hack that I can perform to achieve this? This is probably not possible and I would still "use up" the same GPIO ports anyway, so the only value of an electrical method to trigger the backlight if this were doable is to avoid having to tell Linux about it. Now I followed the helpful tutorial, and have gotten the power-button kernel extension working fine on one of my GPIO click-buttons, and I also have working shell scripts that can switch or toggle the screen backlight (though the commands and what is sent where are a mystery to me), however what I would like is to have a second GPIO click button control the backlight, so I can leave the Pi running longer when it is on a battery when e.g. I've got an Adafruit PiTFT with the buttons on, so I have the potential to use the 4 GPIOs wired up to the buttons to control stuff. There's already a question about that here -> "X11" and "Xorg" (or just plain "X") all refer to the same thing X11 is just an older name. What you most likely want to do is just run bare Xorg with one application, yours. To complete a genuinely useful, reasonably complex app this way, get yourself a team and (presuming you are all putting in at least a few dozen hours a week) consider a release date for sometime next spring. To replicate that on the framebuffer, set aside a few weeks and multiply the LOC by several orders of magnitude. I'm sure you can write a normal (Xorg windowing system based) GUI in python in minutes with a few dozen lines of code.
#HOW TO SET UP RETROPIE ON PITFT SOFTWARE#
You can write software that will run without Xorg on the framebuffer, but that would not be the normal way to do this kind of thing, since it can't then be used any other way and (more importantly) will be ridiculously labour intensive. You don't need to use a DE, and you can write GUI software that will run with or without one
(this is WRT a question about Lubuntu, but it applies equally to any normative GNU/Linux distribution including those used on the pi). Gnome and LXDE are both "desktop environments" (DE's) I have a more in-depth explanation of what that means