I received my Adafruit 2.8″ capacitive touch screen a little while ago and have been messing around with it. I followed the Adafruit guide found here and was able to get it working. I also find some instructions here to get the Pi to boot directly to the screen. The instructions essentially boil down to the following:
Install xserver-xorg-video-fbdev (My Raspbian image already had it installed)
sudo apt-get install xserver-xorg-video-fbdev
Create a config file with following contents in /usr/share/X11/xorg.conf.d/99-fbdev.conf containing the following:
Option "fbdev" "/dev/fb1"
After doing the above, my Pi boots to the piTFT screen. I then went about and set TightVNCserver to autostart.
My next steps include getting my basic Python TKinter app to load on boot and fill the screen. Once I have the screen functioning the way I want it for the Thermostat project, I’ll verify powering from the 24V AC line still works OK.