Difference between revisions of "Template:RPi LCD User Manual"

Latest revision as of 09:31, 6 February 2024

Getting Started

Hardware Connection

There are 40 pins on Raspberry Pi, but there are 26 pins on the LCD, so you should pay attention to connecting the pins to your Pi accordingly.

Touch Driver Installation

The RPi LCD can be driven in two ways:
Method 1. Install the driver to your Raspbian OS.
Method 2. Use the Ready-to-use image file of which the LCD driver was pre-installed.

Method 1. Driver installation

Please download the bullseye 32bit version of the image on the Raspberry Pi official website. (Raspbian/Ubuntu Mate/Kali or Retropie)

1) Download the compressed image file to the PC, and unzip it to get the .img file.

2) Connect the TF card to the PC, open the Win32DiskImager software, select the system image downloaded in step 1, and click 'Write' to write the system image. ( How to write an image to a micro SD card for your Pi? See RPi Image Installation Guides for more details)

3) Connect the TF card to the Raspberry Pi, and start the Raspberry Pi. The LCD will display after booting up, and then log in to the Raspberry Pi terminal,(You may need to connect a keyboard and HDMI LCD to Pi for driver installation, or log in remotely with SSH.)

4) Then open the terminal of Raspberry Pi to install the touch driver.

git clone https://github.com/waveshare/LCD-show.git
cd LCD-show/

Note: The Raspberry Pi must be connected to the network, or else the touch driver won't be successfully installed.

For 2.8inch RPi LCD (A):

./LCD28-show

For 3.2inch RPi LCD (B):

./LCD32-show

For 3.2inch RPi LCD (C):

./LCD32C-show

For 3.5inch RPi LCD (A):

./LCD35-show

For 3.5inch RPi LCD (B):

./LCD35B-show

For 3.5inch RPi LCD (C):

./LCD35C-show

For 4inch RPi LCD (A):

./LCD4-show

For 4inch RPi LCD (C):

./LCD4C-show

The touch function will work after restart. For ease of use, you can set the screen orientation, see: #Screen orientation settings.

Notes:

1. Executing apt-get upgrade will cause the LCD to fail to work properly. In this case, you need to edit the config.txt file in the SD card and delete this sentence: dtoverlay=ads7846.
2. Using Raspbian-lite, the command of the touch driver installation should be:
For 2.8inch RPi LCD (A):

./LCD28-show lite

For 3.2inch RPi LCD (B):

./LCD32-show lite

For 3.2inch RPi LCD (C):

./LCD32C-show lite

For 3.5inch RPi LCD (A):

./LCD35-show lite

For 3.5inch RPi LCD (B):

./LCD35B-show lite

For 3.5inch RPi LCD (C):

./LCD35C-show lite

For 4inch RPi LCD (A):

./LCD4-show lite

For 4inch RPi LCD (C):

./LCD4C-show lite

For bullseye 64bit systems, manual configuration is required as follows: 3.5inch RPi LCD (B) Manual Configuration.

Method 2. Using Ready-to-use image

The image file with the 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 into your Pi, power up, and enjoy it.

Screen Orientation Settings

After installing the touch driver, you can modify the screen rotation direction by running the following commands.

cd LCD-show/
#X can be 0, 90, 180, and 270. Indicates that the LCD rotates 0 degrees, 90 degrees, 180 degrees, and 270 degrees, respectively.
#If it is an old version, execute the following code:
sudo ./LCD28-show X
#If it is a new version, execute the following code:
sudo ./LCD28-show-V2 X

The rotation command under Raspbian-lite is as follows:

cd LCD-show/
#X can be 0, 90, 180, and 270. Indicates that the LCD rotates 0 degrees, 90 degrees, 180 degrees, and 270 degrees, respectively.
#If it is an old version, execute the following code:
sudo ./LCD28-show lite X
#If it is a new version, execute the following code:
sudo ./LCD28-show-V2 lite X

Touch screen calibration

This LCD can be calibrated through the xinput-calibrator demo. Note: The Raspberry Pi must be connected to the network, or else the program won't be successfully installed.

Run the following command to install:

sudo apt-get install xinput-calibrator

Click the "Menu" button on the taskbar, and choose "Preference" -> "Calibrate Touchscreen".
Finish the touch calibration following the prompts. Maybe rebooting is required to make calibration active.
You can create a 99-calibration.conf file to save the touch parameters (not necessary if the file exists).

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

Save the touch parameters (may differ depending on LCD) to 99-calibration.conf, as shown in the picture:

Control Backlight Brightness with GPIO

Use a 0R resistor or solder to connect this pad.

Execute the following command on the Raspberry Pi terminal to control the backlight brightness:

gpio -g pwm 18 1024
gpio -g mode 18 pwm (the occupied pins are PWM pins)
gpio pwmc 1000
gpio -g pwm 18 X (control brightness, the X value is between 0~1024)

Install Virtual Keyboard

1. Install matchbox-keyboard.

sudo apt-get install update
sudo apt-get install matchbox-keyboard
sudo nano /usr/bin/toggle-matchbox-keyboard.sh

2. Copy the statements below to toggle-matchbox-keyboard.sh and save.

#!/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 commands:

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 statements to toggle-matchbox-keyboard.desktop and save.

[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. Execute commands as below. Note that you need to use "Pi " user permission instead of root to execute this command.

sudo nano /etc/xdg/lxpanel/LXDE-pi/panels/panel

6. Find the statement that is similar to below: (It may be different in different versions.)

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

7. Append these statements to add a button option:

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

8. Reboot your Raspberry Pi. If the virtual keyboard is installed correctly, you can find that there is a keyboard icon on the left of the bar.

sudo reboot

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