Raspbian : 3.5 LCD

The RPi LCD can be driven in two ways:

• Method 1. install driver to your Raspbian OS.
• Method 2. use the Ready-to-use image file of which LCD driver was pre-installed.

Method 1. Driver installation

Description: Supports the latest version of Raspbian and Ubuntu Mate. * LCD-show-160811.tar.gz

1. Configure your Pi:

sudo raspi-config

Set as: * Select Expand Filesystem.

• Boot Option -> Desktop Autologin (may differ depending on Raspbian revision)

2. Copy the driver (choose the driver according to your OS) into your OS then Run the following commands:

tar xvf LCD-show-YYMMDD.tar.gz
cd LCD-show/

This toggles the mode to LCD display: ./LCD35-show

3. After system rebooting, the RPi LCD is ready to use.

Method 2. Using Ready-to-use image

The image file with pre-installed driver is located in the IMAGE directory of the CD, or you can download it from #Image. Extract the .7z file and you will get an .img file. Write the image to your micro SD card (How to write an image to a micro SD card for your Pi? See RPi Image Installation Guides for more details). Then insert the card to your Pi, power up and enjoy it.

Toggle between LCD and HDMI display

Once this LCD is enabled, meanwhile the default settings for HDMI are changed. If you want to use another HDMI monitor, please run the following command:

cd LCD-show


./LCD-hdmi

This toggles the mode to LCD display:

./LCD35-show

Screen orientation settings

After touch driver installed, the screen orientation can be set by these commands:

• 0 degree rotation

cd LCD-show/
./LCD35-show 0

• 90 degree rotation

cd LCD-show/
./LCD35-show 90

• 180 degree rotation

cd LCD-show/
./LCD35-show 180

• 270 degree rotation

cd LCD-show/
./LCD35-show 270

Touch screen calibration

This LCD can be calibrated using a program called xinput_calibrator which is pre-installed on the CD image. However, it was not pre-installed on original Raspbian OS. So in this case, you should get and install the program manually with

sudo apt-get install -y xinput-calibrator

Enter the following commands for touch screen calibration:

sudo DISPLAY=:0.0 xinput_calibrator

or select Menu -> Preferences -> Calibrate Touchscreen.

After running these commands, there will be a prompt for four-point calibration shown in the LCD screen. Click the points one by one to finish the touch calibration. Then, the new calibration data will be displayed in the terminal, as shows below. Please get these data for future use.

Doing dynamic recalibration:
Setting new calibration data: 3919, 208, 236, 3913

Enter the following command to edit 99-calibration.conf:

sudo nano /etc/X11/xorg.conf.d/99-calibration.conf

Then, the old calibration data will be displayed in the terminal:

 Section "InputClass"
Identifier      "calibration"
MatchProduct    "ADS7846 Touchscreen"
Option  "Calibration"   "160 3723 3896 181"
Option  "SwapAxes"      "1"
EndSection

Modify the calibration data to the new calibration data displayed in the step 2):

Section "InputClass"
Identifier      "calibration"
MatchProduct    "ADS7846 Touchscreen"
Option  "Calibration"   "3919 208 236 3913"
Option  "SwapAxes"      "1"
EndSection

Press the keys Ctrl+X, and select the option Y to save the modification.

The modification will be valid after rebooting the system. Enter the following command for system reboot:

sudo reboot

Notices: In case of inaccurate touch, please perform screen calibration again and reboot the system.