Introduction

The 3.5-inch RPi LCD (G) is equipped with a resistive touch screen with a resolution of 320 × 480, supporting two connection methods: Pigo pin communication and GH1.25 11PIN cable connection, and providing example materials for Raspberry Pi, ESP32, Pico, Arduino, etc.

Features

• 320×480 resolution, 262K RGB colors, clear and colorful displaying effect
• High touch screen transmittance, fast response and long lifetime
• Embedded with ST7796S driver chip and XPT2046 resistive touch control chip, using SPI communication, minimizes required IO pins
• Supports two connection methods: Pigo pin communication and GH1.25 11PIN cable connection
• Adopts Immersion Gold process, nice looking, with better durability
• Provides complete demos and development materials for Raspberry Pi, Raspberry Pi Pico, ESP32 and Arduino platforms

Interfaces

Dimensions

Specifications

Configure Driver File

Refer to the steps here first #Install Driver Module

• Edit config.txt configuration file

sudo nano /boot/firmware/config.txt

Comment out the dual-screen configuration statements

Add the following statements at the end of [all]

dtparam=i2c_arm=on
dtparam=i2c_arm_baudrate=50000
dtparam=spi=on
dtoverlay=Waveshare35g,fps=60,speed=48000000,rotate=90,penirq=17
hdmi_force_hotplug=1
max_usb_current=1
hdmi_group=2
hdmi_mode=87
hdmi_cvt 480 320 60 6 0 0 0
hdmi_drive=2

Create Screen Configuration File

Create 98-spi-screen.conf file

sudo nano /etc/X11/xorg.conf.d/98-spi-screen.conf 

Add the following parameters to 98-spi-screen.conf file

Section "Device"
    Identifier "SPI Screen"    
    Driver "fbdev"
    Option "fbdev" "/dev/fb0"
EndSection

Note: After the entire process operation is completed, if they are not displayed, modify "/dev/fb0" to "/dev/fb1" and then restart it

Switch to X11

sudo raspi-config nonint do_wayland W1

Calibrate Resistive Touch Screen

Run the following statements on the terminal:

sudo apt-get install xserver-xorg-input-evdev 
sudo cp -rf /usr/share/X11/xorg.conf.d/10-evdev.conf /usr/share/X11/xorg.conf.d/45-evdev.conf
sudo apt-get install xinput-calibrator
sudo nano /usr/share/X11/xorg.conf.d/99-calibration.conf

Add the following statements in the 99-calibration.conf file:

Section "InputClass"
        Identifier      "calibration"
        MatchProduct    "ADS7846 Touchscreen"
        Option  "Calibration"   "3932 300 294 3801"
        Option  "SwapAxes"      "1"
        Option "EmulateThirdButton" "1"
        Option "EmulateThirdButtonTimeout" "1000"
        Option "EmulateThirdButtonMoveThreshold" "300"
EndSection

Restart to take effect

It must be operated based on the bookworm lite version, 64-bit lite or 32-bit lite

Configure Driver File

Refer to the steps here first #Install Driver Module

• Edit config.txt configuration file

sudo nano /boot/firmware/config.txt

Comment out the KMS and dual-screen configuration statements

Add the following statements at the end of [all]

dtparam=i2c_arm=on
dtparam=i2c_arm_baudrate=50000
dtparam=spi=on
dtoverlay=Waveshare35g,fps=60,speed=48000000,rotate=90,ts_rotate_90
hdmi_force_hotplug=1
max_usb_current=1
hdmi_group=2
hdmi_mode=87
hdmi_cvt 480 320 60 6 0 0 0
hdmi_drive=2

Download Necessary Softwares

• Install the Xorg service

sudo apt-get install --no-install-recommends xserver-xorg -y
sudo apt-get install --no-install-recommends xinit -y

• Install desktop manager

sudo apt install lightdm -y

• Install official Raspberry Pi GUI

sudo apt install raspberrypi-ui-mods -y  

• Install git

sudo apt install git -y

• Install a browser (optional)

sudo apt install chromium-browser -y

• Install a music player (optional)

sudo apt install vlc -y

Download and Run Driver

Open the Raspberry Pi terminal and execute:

sudo apt install libraspberrypi-dev -y
sudo apt-get install unzip -y
sudo apt-get install cmake -y
sudo wget https://files.waveshare.com/wiki/common/Rpi-fbcp.zip
sudo unzip ./Rpi-fbcp.zip
cd rpi-fbcp/
sudo rm -rf build
sudo mkdir -m 777 ./build
cd ./build
sudo cmake ..
sudo make -j4
sudo install fbcp /usr/local/bin/fbcp

Set Auto-start startx and fbcp

• Open the Bash shell file, or create one if it does not exist

sudo nano ~/.bashrc

Add the following code to the end of the file

if [ "$(cat /proc/device-tree/model | cut -d ' ' -f 3)" = "5" ]; then
    # rpi 5B configuration
    export FRAMEBUFFER=/dev/fb1
    startx  2> /tmp/xorg_errors
else
    # Non-pi5 configuration
    export FRAMEBUFFER=/dev/fb0
    startx  2> /tmp/xorg_errors
fi

• Create and edit a fbcp service file for autostart

sudo nano /etc/systemd/system/fbcp.service

Add service configuration in the file

[Unit]
Description=Framebuffer Copy for Raspberry Pi
After=network.target

[Service]
ExecStartPre=/bin/sleep 20
ExecStart=/usr/local/bin/fbcp
Restart=always
User=root
Group=root

[Install]
WantedBy=multi-user.target

Reload the systemd configuration

sudo systemctl daemon-reload

The service enables auto-start at boot

sudo systemctl enable fbcp.service

Test the startup service

sudo systemctl start fbcp.service

Calibrate Resistive Touch Screen

Run the following statements on the terminal:

sudo apt-get install xserver-xorg-input-evdev 
sudo cp -rf /usr/share/X11/xorg.conf.d/10-evdev.conf /usr/share/X11/xorg.conf.d/45-evdev.conf
sudo apt-get install xinput-calibrator
sudo nano /usr/share/X11/xorg.conf.d/99-calibration.conf

Add the following statements in the 99-calibration.conf file:

Section "InputClass"
        Identifier      "calibration"
        MatchProduct    "ADS7846 Touchscreen"
        Option  "Calibration"   "3932 300 294 3801"
        Option  "SwapAxes"      "1"
        Option "EmulateThirdButton" "1"
        Option "EmulateThirdButtonTimeout" "1000"
        Option "EmulateThirdButtonMoveThreshold" "300"
EndSection

Set CLI Auto-login

sudo raspi-config nonint do_boot_behaviour B2
sudo raspi-config nonint do_wayland W1
sudo reboot

Note1: Make sure that the username of the Raspberry Pi is pi, otherwise it will not be able to log in automatically
Note2: After setting all the configurations above, the system takes longer to restart each time, and SSH also requires a moment to enter

Install Driver Module

• Determine the current kernel version

uname -a

This command will output the complete kernel version information. For example, executing this command on Raspberry Pi 5 may produce the following output:

Linux raspberrypi 6.1.21-v8+ #1642 SMP PREEMPT Mon Apr  3 17:24:16 BST 2023 aarch64 GNU/Linux

This indicates that the kernel version number of this system is 6.1.21, and it uses 64-bit ARM (AArch64) architecture.

• Download and install the ST7796 driver module

# Step 1: Download and enter the Waveshare-st7796s driver folder
wget https://files.waveshare.com/wiki/common/Waveshare-st7796s.zip
unzip Waveshare-st7796s.zip
cd Waveshare-st7796s
 
# Step 2: cd to the directory of the corresponding kernel version number
# Run the following command as in the example above
cd 6.1.21/64/

# Copy the corresponding version of st7796s.ko to the current system
sudo cp st7796s.ko /lib/modules/$(uname -r)/kernel/drivers

# Make sure the module is loaded at boot time, add the module name to the /etc/modules file:
sudo nano /etc/modules

# Add at the end
st7796s

Enter the following statement in the terminal to handle kernel module dependencies:

sudo depmod -a

• Configure driver device tree

cd
wget https://files.waveshare.com/wiki/common/Waveshare35g.dtbo
sudo cp Waveshare35g.dtbo /boot/overlays/

Configure Driver File

Refer to the steps here first #Install Driver Module

• Edit config.txt configuration file

sudo nano /boot/config.txt

Comment out the KMS and dual-screen configuration statements

Add the following statements at the end of [all]

dtparam=i2c_arm=on
dtparam=i2c_arm_baudrate=50000
dtparam=spi=on
dtoverlay=Waveshare35g,fps=60,speed=48000000,rotate=90,penirq=17
hdmi_force_hotplug=1
max_usb_current=1
hdmi_group=2
hdmi_mode=87
hdmi_cvt 480 320 60 6 0 0 0
hdmi_drive=2

Download and Run Driver

Open the Raspberry Pi terminal and execute:

sudo apt install libraspberrypi-dev -y
sudo apt-get install unzip -y
sudo apt-get install cmake -y
sudo wget https://files.waveshare.com/wiki/common/Rpi-fbcp.zip
sudo unzip ./Rpi-fbcp.zip
cd rpi-fbcp/
sudo rm -rf build
sudo mkdir -m 777 ./build
cd ./build
sudo cmake ..
sudo make -j4
sudo install fbcp /usr/local/bin/fbcp

Set Auto-start fbcp

• Open rc.local file

sudo nano /etc/rc.local

Before adding the following code to exit 0, be sure to add "&" to run in the background, otherwise the system may not start.

sleep 20
fbcp &

Calibrate Resistive Touch Screen

Run the following statements on the terminal:

sudo apt-get install xserver-xorg-input-evdev 
sudo cp -rf /usr/share/X11/xorg.conf.d/10-evdev.conf /usr/share/X11/xorg.conf.d/45-evdev.conf
sudo apt-get install xinput-calibrator
sudo nano /usr/share/X11/xorg.conf.d/99-calibration.conf

Add the following statements in the 99-calibration.conf file:

Section "InputClass"
        Identifier      "calibration"
        MatchProduct    "ADS7846 Touchscreen"
        Option  "Calibration"   "3932 300 294 3801"
        Option  "SwapAxes"      "1"
        Option "EmulateThirdButton" "1"
        Option "EmulateThirdButtonTimeout" "1000"
        Option "EmulateThirdButtonMoveThreshold" "300"
EndSection

Restart to take effect