4inch DPI LCD (C)

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4inch DPI LCD (C)
4inch-DPI-LCD-C-1.jpg

4inch Square Capacitive Touch Screen LCD (C) for Raspberry Pi, 720×720, DPI, IPS
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Primary Attribute
Category: OLEDs / LCDs, LCD, Raspberry Pi LCD
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Brand: Waveshare
Website
International: 4inch DPI LCD(C)
Chinese: 4inch DPI LCD(C)
Onboard Interfaces
RPi I/Os DPI
Related Products

Introduction

4inch Square Capacitive Touch Screen LCD (C) For Raspberry Pi, 720×720, DPI, IPS, Toughened Glass Cover, Low Power Solution

Features

  • 4inch IPS Display, 720x720 hardware resolution.
  • Designed for Raspberry Pi, based on Raspberry Pi 40pin GPIO interface.
  • Using DPI666 interface of Raspberry Pi to drive LCD, refresh rate up to 60Hz.
  • Drive capacitive touch through I2C interface of Raspberry Pi, 5-points touch, toughened glass panel, hardness up to 6H.
  • Supports Raspbian and Kali systems.

How to use

This LCD can support Raspbian and Kali systems.

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

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

2) Connect the TF card to the PC, use SDFormatter.exe software to format the TF card.

3) Open the Win32DiskImager.exe software, select the system image downloaded in step 1, and click‘Write’ to write the system image.

4) After the image has finished writing, open the config.txt file in the root directory of the TF card(/boot/), add the following code at the end of config.txt, then save and quit the TF card safely.

gpio=0-9=a2
gpio=12-17=a2
gpio=20-25=a2
dtoverlay=dpi24
enable_dpi_lcd=1
display_default_lcd=1
extra_transpose_buffer=2
dpi_group=2
dpi_mode=87
dpi_output_format=0x7f216
dpi_timings=720 0 46 2 42 720 0 16 2 18 0 0 0 60 0 60000000 6
dtoverlay=waveshare-4dpic-3b-4b
dtoverlay=waveshare-4dpic-3b
dtoverlay=waveshare-4dpic-4b

Note: For Raspberry Pi 4, you need to comment out dtoverlay=vc4-fkms-V3D.

5)Download the 4inch DPI LCD (C) DTBO file and extract 3 dtbo files. Copy these three files to the overlays directory (/boot/overlays/), as shown in the following figure:

4inch-DPI-LCD-C-Manual01.jpg

6) Save and quit the TF card safely, and insert the TF card into the Raspberry Pi.

7) Insert the 4inch DPI LCD (C) into the 40PIN GPIO interface of the Raspberry Pi, power on the Raspberry Pi, and wait for about ten seconds to display normally.

Rotation(Working with Raspberry Pi)

Display Rotating

Add this statement in the config.txt file (the config file is located in the root directory of the TF card, which is named /boot):

display_rotate=1 #1:90;2: 180; 3: 270

And then restart the Raspberry Pi after saving.

sudo reboot

Touch Rotating

After the display is rotated, the position of touch is incorrect because the touch doesn’t change with the display angle. So the touch also needs to be modified.

1.Install libinput.

sudo apt-get install xserver-xorg-input-libinput

If the system you installed is Ubuntu or Jetson Nano. The installation code is:

sudo apt install xserver-xorg-input-synaptics

2.Create the xorg.conf.d directory under /etc/X11/ (if the directory already exists, proceed directly to step 3).

sudo mkdir /etc/X11/xorg.conf.d

3.Copy the 40-libinput-conf file to the directory you created just now.

sudo cp /usr/share/X11/xorg.conf.d/40-libinput.conf /etc/X11/xorg.conf.d/

4.Edit this file.

sudo nano /etc/X11/xorg.conf.d/40-libinput.conf

Find the part of the touchscreen, add the following statement inside, and then save the file.

Option "CalibrationMatrix" "0 1 0 -1 0 1 0 0 1"

Similar to the picture below:

Touch roate.jpg
5. save and reboot your Pi

sudo reboot

After completing these steps. The LCD could rotate 90 degrees both display and touch function.

Note:

90 degree: Option "CalibrationMatrix" "0 1 0 -1 0 1 0 0 1"

180 degree: Option "CalibrationMatrix" "-1 0 1 0 -1 1 0 0 1"

270 degree: Option "CalibrationMatrix" "0 -1 1 1 0 0 0 0 1"


Others

Disable power saving.

If you want to keep the display turning on all the time, you can disable the power saving function.
Modify file lightdm.conf

sudo nano /etc/lightdm/lightdm.conf

Find the [SeatDefaults] option and uncomment the line"xserver-command", modify it as below:

#xserver-command=X

Modify this code to

xserver-command=X -s 0 -dpms
  • -s # –Disable the display protecting.
  • dpms Disable power saving.

Reboot

sudo reboot

Turn on/off HDMI output

You can use the following commands to disable/enable the displaying.

vcgencmd display_power 0
vcgencmd display_power 1

Adjust brightness by PWM

Update wiringPi if you use Pi4.

wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
gpio -v
# It should be 2.52 version

Change the brightness by the following command

gpio -g mode 18 pwm      #Set the pin for PWM
gpio pwmc 100   
gpio -g pwm 18 0         #Bightest
gpio -g pwm 18 1023      #Dimest
gpio -g mode 18 out      #Clean the GPIO

Interface

The pins labeled "NC" below means that those pins of Raspberry Pi are not occupied by the LCD, and the user can use them for other applications.

PIN NO. SYMBOL DESCRIPTION
1 NC Power positive (3.3V power input)
2 5V Power positive (5V power input)
3 VSYNC Vertical sync
4 5V Power positive (5V power input)
5 HSYNC Horizontal sync
6 GND Ground
7 B0 RGB signal cable
8 G2 RGB signal cable
9 GND Ground
10 G3 RGB signal cable
11 G5 RGB signal cable
12 AUDIO Audio output
13 TP_INT Touch Panel interrupt
14 GND Ground
15 R2 RGB signal cable
16 R3 RGB signal cable
17 NC Power positive (3.3V power input)
18 R4 RGB signal cable
19 TP_SDA I2C SDA for touch panel
20 GND Ground
21 B5 RGB signal cable
22 R5 RGB signal cable
23 TP_SCL I2C SCL for touch panel
24 B4 RGB signal cable
25 GND Ground
26 B3 RGB signal cable
27 LCD_CLK LCD clock
28 DE LCD data enable
29 B1 RGB signal cable
30 GND Ground
31 B2 RGB signal cable
32 G0 RGB signal cable
33 G1 RGB signal cable
34 GND Ground
35 NC GPIO interface
36 G4 RGB signal cable
37 NC GPIO interface
38 R0 RGB signal cable
39 GND Ground
40 R1 RGB signal cable

FAQ

Anti-Piracy

Since the first-generation Raspberry Pi released, Waveshare has been working on designing, developing, and producing various fantastic touch LCDs for the Pi. Unfortunately, there are quite a few pirated/knock-off products in the market. They're usually some poor copies of our early hardware revisions, and comes with none support service.

To avoid becoming a victim of pirated products, please pay attention to the following features when purchasing:

RPi-LCD-Anti-Piracy.jpg

(Click to enlarge)

Beware of knock-offs

Please note that we've found some poor copies of this item in the market. They are usually made of inferior materials and shipped without any testing.

You might be wondering if the one you're watching or you've purchased in other non-official stores is original, feel free to contact us.

Support

Please contact us by Email/Skype/WeChat for technology support.Our response may be delay, you can just leave your questions, we will reply to you as soon as possible in working time.

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