To rotate the screen, please follow theinstructions for the Raspberry Pi.

After rotating the screen, you will need to recalibrate the touchscreen or, in X Windows, you can add a transformation matrix like the following:

# 90-degree clockwise rotation
xinput set-prop "Microchip Technology Inc. AR1100 HID-MOUSE" "Coordinate Transformation Matrix" 0 1 0 -1 0 1 0 0 1
 
# 90-degree counterclockwise rotation
xinput set-prop "Microchip Technology Inc. AR1100 HID-MOUSE" "Coordinate Transformation Matrix" 0 -1 1 1 0 0 0 0 1
 
# 180-degree rotation
xinput set-prop "Microchip Technology Inc. AR1100 HID-MOUSE" "Coordinate Transformation Matrix" -1 0 1 0 -1 1 0 0 1