1,550 bytes added, 
16:36, 20 October 2016 
==Use the Raspberry OS that we provide==
* On the Terminal, enter
  ''sudo su''
  ''DISPLAY=:0.0 xinput_calibrator''
 Then the sreen will show 4 points. You need to click 4 points step by step to calibrate. After calibration, you will get 4 new calibration numbers. Copy them.
 [[File:3.5inchCali1.jpg|800px]]
* On the Terminal, enter
  ''sudo nano /usr/share/X11/xorg.conf.d/01-input.conf''
  Use the 4 new numbers replace the 4 old numbers ,Press the keyboard “Ctrl + X” ,then choice “Y”, Press the  ”Enter” exit.
* On the Terminal, enter
 ''sudo reboot''
 After reboot ,the calibration will be ok
== Use your own Raspbian OS(Such as official Raspbian OS) ==
* Download the [http://www.raspberrypiwiki.com/download/images/xinput-calibrator.deb xinput] calibration software .Copy it to your Raspbery Pi
* Install the software.On the Terminal, enter
  ''sudo dpkg -i -B xinput-calibrator.deb''
* On the Terminal, enter
  ''sudo su'' 
  ''DISPLAY=:0.0 xinput_calibrator''
  Then the sreen will show 4 points. You need to click 4 points step by step to calibrate. After calibration, you will get the following. Copy them.
[[File:3.5inchCali2.jpg|800px]]
* On the Terminal, enter
  ''sudo mkdir /etc/X11/xorg.conf.d''
  ''sudo nano /etc/X11/xorg.conf.d/99-calibration.conf''
  Past what you have copied just now to the file
[[File:3.5inchCali3.jpg|800px]]
  Press the keyboard "Ctrl + X" ,choice the "Y" ,Then press ”Enter”  to save the file
* On the Terminal, enter
  ''sudo reboot''
  After reboot ,the calibration will be ok