How many of the GPIO pins PiTFT - 2.8" TFT 320 x 240 CapacitiveTouchscreen uses?

Question

I am planning on using the PiTFT - 2.8" TFT 320 x 240 CapacitiveTouchscreen with my Raspberry PI 2 Model B with 40 GPIO pins and would like to know how many of the 26 GPIO pins it uses even though it completely covers all 26 pins.

PiTFT - 2.8" TFT 320 x 240

Answer 1

From your link.

Uses the hardware I2C Pins (SDA & SCL), SPI pins (SCK, MOSI, MISO, CE0) as well as GPIO #25 and #24. All other GPIO are unused and you can still share the I2C pins with sensors, LED drivers, etc. Since we had a tiny bit of space, there's 4 spots for optional slim tactile switches wired to four GPIOs, that you can use if you want to make a basic user interface. For example, you can use one as a power on/off button. See below for the link to get the optional tact switches, they're not included.

Therefore it uses 8 GPIO.

There are 40 pins on the Pi2's expansion header, of which 26 are usable GPIO. That means you have 18 spare GPIO.