Tactile switch as power button
Its a good idea to safely turn off your Pi with a good sudo shutdown -h now but that often means pulling out a keyboard or connecting to the console. With our kernel we added a cool module that will let you turn any GPIO into a power button. Since there's a couple of tactile switches right there on the front, lets turn one into a power button. Press once to properly turn off the pi, press again to start it up. Isn't that nice?
We'll be using GPIO #23, the third button. You can use any of them or other GPIO but #23's our favorite number anyways.
Add rpi_power_switch to /etc/modules and save
Now create a new conf file or edit our existing one with
sudo nano /etc/modprobe.d/adafruit.conf
and enter in the line
options rpi_power_switch gpio_pin=23 mode=0
Of course, change the gpio_pin setting to some other # if you wish. mode=0 means its a pushbutton not a switch. If you happen to install an on/off switch, use mode=1
To make it active immediately run sudo modprobe rpi_power_switch
Boot to X Windows on PiTFT
To enable booting straight to X windows on the PiTFT follow the steps below. First make sure a display configuration which would conflict is not present by executing in a terminal on the Pi:
sudo mv /usr/share/X11/xorg.conf.d/99-fbturbo.conf ~
Don't worry if the command fails with an error that the file doesn't exist. This failure is normal and should happen on a good PiTFT install. You can ignore it and move on.
Next run the command below to open the nano text editor as root and create the file /usr/share/X11/xorg.conf.d/99-pitft.conf:
sudo nano /usr/share/X11/xorg.conf.d/99-pitft.conf
When the editor loads to a blank file, copy in the text below:
Section "Device" Identifier "Adafruit PiTFT" Driver "fbdev" Option "fbdev" "/dev/fb1" EndSection
Then save the file by pressing Ctrl-O and then enter, and finally exit by pressing Ctrl-X.
The step above will create a configuration file which tells X windows that it should use the PiTFT framebuffer (located at /dev/fb1) by default when it runs.
At this point you can use the raspi-config tool to enable booting to desktop just like normal on the Pi. Run the following command:
sudo raspi-config
Then pick the Enable Boot to Desktop/Scratch option and choose if you want to boot to the console, desktop, or scratch environment. After exiting the tool and rebooting you should see the Pi load X windows on the PiTFT after (be patient it can take around 30 seconds to load).
If you want to disable booting to X, just use the raspi-config command again to choose the console boot option
