https://github.com/UCTRONICS/UCTRONICS_LCD35_RPI/blob/master/Troubleshooting.md

Install the UCTRONICS_LCD35_RPI is very easy.
Just run

wget https://raw.githubusercontent.com/UCTRONICS/UCTRONICS_LCD35_RPI/master/install

sudo chmod +x install

sudo ./install 

If you want to know the detail operations see the follows.

This driver package is used for UCTRONICS 3.5 inches LCD which can run on Raspbery Pi zero Pi2 Pi3 Model B/B+ paltforms.

In order to use it easier,we provide you operation steps in detail.

Step1: Expand the sd card first

sudo raspi-config choose Advanced Operations -> Expand Filesystem 

sudo reboot

Step2: Update your raspberry pi system

 sudo apt-get update

Step3: Download the driver package

 sudo git clone https://github.com/UCTRONICS/UCTRONICS_LCD35_RPI.git

Step4: Come in the UCTRONICS_LCD35_RPI

cd UCTRONICS_LCD35_RPI

Step5: Get run permissions

 sudo chmod 777 UCTRONICS_LCD_backup

 sudo chmod 777 UCTRONICS_LCD35_install

 sudo chmod 777 UCTRONICS_LCD_restore

 sudo chmod 777 UCTRONICS_LCD_hdmi

Step6: backup data

 sudo ./UCTRONICS_LCD_backup

Step7: install the LCD35 driver

 sudo ./UCTRONICS_LCD35_install

wait a while the system will be installed and restarted automatically.
if you want to reuse the pre-installation system, you can use the below command

 sudo ./UCTRONICS_LCD_restore

If you want to display on hdmi instead of LCD,just use the below command

   sudo ./UCTRONICS_LCD_hdmi

Add more functions for the LCD :

NO1. Install calibration software for calibration

  cd UCTRONICS_LCD35_RPI

  sudo unzip Xinput-calibrator_0.7.5-1_armhf.zip 

  cd xinput-calibrator_0.7.5-1_armhf/

  sudo dpkg -i -B xinput-calibrator_0.7.5-1_armhf.deb

NO2. Install virtual keyboard

1. Execute the following commands to install the corresponding software

 sudo apt-get update

 sudo apt-get install matchbox-keyboard

 sudo nano /usr/bin/toggle-matchbox-keyboard.sh

2. Copy the following contents to toggle box - keyboard. Sh, save the exit

  #!/bin/bash
   #This script toggle the virtual keyboard
   PID=`pidof matchbox-keyboard`
  if [ ! -e $PID ]; then
   killall matchbox-keyboard
   else
   matchbox-keyboard -s 50 extended&
   fi

3. Execute the following command

sudo chmod +x /usr/bin/toggle-matchbox-keyboard.sh

sudo mkdir /usr/local/share/applications

sudo nano /usr/local/share/applications/toggle-matchbox-keyboard.desktop

4. Copy the following contents to toggle - matchbox - keyboard. Desktop, save exit

[Desktop Entry]
Name=Toggle Matchbox Keyboard 
Comment=Toggle Matchbox Keyboard` 
Exec=toggle-matchbox-keyboard.sh
Type=Application
Icon=matchbox-keyboard.png
Categories=Panel;Utility;MB
X-MB-INPUT-MECHANSIM=True

5. To perform the following command, note that this step must use the "PI" user permission, and if the administrator privileges are used, the file will not be found

nano ~/.config/lxpanel/LXDE-pi/panels/panel

6. Find similar commands (different versions of ICONS may differ)

Plugin {
type = launchbar
Config {
Button {
id=lxde-screenlock.desktop
}
Button {
id=lxde-logout.desktop 
 }
}

7. Add the following code to add a Button item

 Button {
 id=/usr/local/share/applications/toggle-matchbox-keyboard.desktop
  }

8. To restart the system with the following command, you can see a virtual keyboard icon in the top left corner

  sudo reboot

NO3. How to add new ICON to desktop ?

If it's just a folder, add it directly to the desktop

If it is an executable, follow this steps:

• step1: choose the Directory Tree -> / -> usr -> share ->applications folder

• Step2: choose a icon you want to link

• Step3: choose edit -> create link... ->Desktop ->OK

NO4. How to rotate the screen to 180 degree ?

cd UCTRONICS_LCD35_RPI

sudo chmod 777 UCTRONICS_LCD35_rotation_180_install

sudo ./UCTRONICS_LCD35_rotation_180_install