Overview

Introduction

3.5 inch SPI Touch Display is designed for Raspberry Pi.

Features

• 320 x 480 hardware resolution
• Resistive touch control
• Compatible and supported by any version of Raspberry Pi board.(Directly-pluggable)
• Drivers provided (works with your own Raspbian/Ubuntu/Kali)
• Supports FBCP software driver as well, allows to config software resolution and set up dual-display
• Size perfectly fits the Pi (Raspberry Pi B+/2B/3B/3B+)
• Use software keyboard (system interaction without keyboard/mouse)
• Reversible screen display orientation
• PWM backlight brightness controllable
• High-quality PCBs and components.

Key Parameters

Interface definition

The pins marked as “NC” below indicate that the pins are not occupied by the LCD and can be used by the user for other applications.

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. You can also refer to the digram below :

树莓派+屏幕连接图

Install the Driver

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

Please download the latest version of the image on the Raspberry Pi official website.

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 上传到我们自己的服务器再提供链接software, select the system image downloaded in step 1 and click‘Write’ to write the system image.

3) Connect the TF card to the Raspberry Pi, 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 installing, or log in remotely with SSH)

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

git clone https://github.com/osoyoo/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.

chmod +x lcd35b-show
 ./lcd35b-show

The touch function will work after restart. For ease of use, you can set the screen orientation, see the next operations.

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把镜像文件压缩后上传到服务器然后提供下载链接. Extract the .7z file and you will get an .img file. Write the image to your micro SD card. Then insert the card to your Pi, power up and enjoy it.

Rotate the display direction

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 you are using the 3.5inch LCD, execute the following code:
sudo ./lcd35b-show X

Touch screen calibration

This LCD can be calibrated using a program called xinput_calibrator.
This software is automatically installed when we install the screen driver.
Click the Menu button on the task bar, choose Preference -> Calibrate Touchscreen.
Finish the touch calibration following the prompts.

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

提供我们自己操作的图片

Maybe rebooting is required to make calibration active.
You can replace the touch parameters in ../LCD-show/usr/99-calibration.conf-35b-0 folder.

图一

We need calibrate 4 times for 0,90,180,270 rotation, and replace the conf files in the package.

图二

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 which is similar to below: (It maybe different in different version)

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

7. Append these statements to add an button option:

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

提供我们自己操作的图片

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