You can install the touch driver for 3.5″touch screen on an existing system, but it just supports raspbian and ubuntu system.
Raspberry Pi must be connected to the Internet,and you can control it through ssh,vnc, Remote desktop or the other big HDMI display.
Step 1:Open the command terminal,Enter the following commands to download the 3.5″touch screen driver;
sudo git clone https://github.com/kedei/LCD_driver
Step 2:Change file permissions;
sudo chmod -R 777 LCD_driver
Step 3:Enter the folder;
Step 4:Install the driver, RaspberryPi will auto reboot ;
You can use the following command to rotate the screen
Rotate 90° ./LCD35_show 90
Rotate 180° ./LCD35_show 180
Rotate 270° ./LCD35_show 270
DownLoad Url osoyoo.com