Difference between revisions of "3.5inch DPI LCD"
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= Resource = | = Resource = | ||
==3D Drawing== | ==3D Drawing== | ||
− | *[ | + | *[https://www.waveshare.com/w/upload/0/04/3.5inch_DPI_LCD_3D%282%29.zip 3.5inch DPI LCD 3D Drawing] |
== Software == | == Software == |
Revision as of 02:21, 29 July 2022
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Overview
Introduction
640 x 480, 3.5inch IPS Display for Raspberry Pi, DPI interface, 5-points capacitive touch control.
Features
- 3.5inch IPS Display, 640 x 480 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.
Software settings
If you don't know the difference between the two branches of Raspberry Pi OS, you can check the following introduction #Introducing the Raspberry Pi OS fork
For Raspberry Pi OS Bullseye branch
Please download the latest version of the image from the Raspberry Pi official website.
1. Download the compressed file to the PC, and extract the img file.
2. Connect the TF card to the PC and use SDFormatter to format the TF card.
3. Open the Win32DiskImager software, select the system image prepared in step 1, and click write to burn the system image.
4. After the programming is completed, open the config.txt file in the root directory of the TF card, add the following code at the end of config.txt and save it.
dtoverlay=vc4-kms-v3d dtoverlay=vc4-kms-DPI-35inch dtoverlay=waveshare-35dpi-3b-4b dtoverlay=waveshare-35dpi-3b dtoverlay=waveshare-35dpi-4b
5. Download the 3.5inch DPI LCD DTBO file and extract the dtbo files. Copy these files to the overlays directory (/boot/overlays/),
6. Insert the TF card into the Raspberry Pi, power on the Raspberry Pi, and wait for more than 30 seconds to display normally.
For Raspberry Pi OS Buster branch and Ubuntu system
1. Open the config.txt file in the root directory of the TF card, add the following code at the end of config.txt, save and safely eject the TF card.
gpio=0-9=a2 gpio=12-17=a2 gpio=20-25=a2 dtoverlay=dpi18 enable_dpi_lcd=1 display_default_lcd=1 extra_transpose_buffer=2 dpi_group=2 dpi_mode=87 dpi_output_format=0x6f006 hdmi_timings=640 0 20 10 10 480 0 10 5 5 0 0 0 60 0 60000000 1 dtoverlay=waveshare-35dpi-3b-4b dtoverlay=waveshare-35dpi-3b dtoverlay=waveshare-35dpi-4b
Note: If it is Raspberry Pi 4, also need to comment out dtoverlay=vc4-fkms-V3D.
2. Download the 3.5inch DPI LCD DTBO file and extract the dtbo files. Copy these files to the overlays directory (/boot/overlays/),
3. Save and quit the TF card safely, and insert the TF card into the Raspberry Pi.
4. Insert the 3.5inch DPI LCD 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)
Raspberry Pi OS and Kali display rotation
First check whether the KMS or FKMS driver is loaded on the system you are using.
Check method: In /boot/config.txt, check whether the line dtoverlay=vc4-kms-v3d or dtoverlay=vc4-fkms-v3d is turned on.
With KMS or FKMS driver loaded
Use the following command for display rotation:
sudo nano /etc/xdg/lxsession/LXDE-pi/autostart #Enter the command corresponding to the display rotation angle at the end of the autostart file, and it will take effect after rebooting the system. #0: rotate 0 degrees; 1: rotate 270 degrees; 2: rotate 180 degrees; 3: rotate 90 degrees xrandr -o 1
No KMS or FKMS driver loaded
Use the following command for display rotation:
sudo nano /boot/config.txt #Enter the command corresponding to the display rotation angle at the end of the config.txt file, and it will take effect after rebooting the system. #0: rotate 0 degrees; 1: rotate 90 degrees; 2: rotate 180 degrees; 3: rotate 270 degrees display_rotate=3
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:
sudo reboot
After completing these steps. The LCD could rotate 90 degrees in 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
Control brightness by PWM
If you use Pi4, you need to update wiringPi first:
wget https://project-downloads.drogon.net/wiringpi-latest.deb sudo dpkg -i wiringpi-latest.deb gpio -v # Check if it is 2.52 version
Control the brightness by PWM
gpio -g mode 18 pwm #Configure the PIN as PWM mode gpio pwmc 100 gpio -g pwm 18 0 #Brightest gpio -g pwm 18 1023 #Dimmest gpio -g mode 18 out #Clear the PIN to output mode.
Turn on/off HDMI output
You can use the following commands to disable/enable the displaying.
vcgencmd display_power 0 vcgencmd display_power 1
Introducing the Raspberry Pi OS fork
On December 2, 2021, the Raspberry Pi OS for Raspberry Pi split into two branches, the Buster branch and the Bullseye branch.
The Buster branch is a continuation of the old system, which is more stable and uses raspicam as the default camera subsystem.
The Bullseye branch adds some new features, including KMS as the default display driver and libcamera as the default camera subsystem.
Image download address
More detailed information can be found at:
Notes:The above information was updated on January 24, 2022. Due to the frequent update of the Raspberry Pi image, when you see this information, the relevant information may be out of date. The actual performance of the image shall prevail. This is for reference only.
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 | B2 | RGB signal cable |
8 | G4 | RGB signal cable |
9 | GND | Ground |
10 | G5 | RGB signal cable |
11 | G7 | RGB signal cable |
12 | PWM | Backlight control |
13 | TP_INT | Touch Panel interrupt |
14 | GND | Ground |
15 | R4 | RGB signal cable |
16 | R5 | RGB signal cable |
17 | NC | Power positive (3.3V power input) |
18 | R6 | RGB signal cable |
19 | TP_SDA | I2C SDA for touch panel |
20 | GND | Ground |
21 | B7 | RGB signal cable |
22 | R7 | RGB signal cable |
23 | TP_SCL | I2C SCL for touch panel |
24 | B6 | RGB signal cable |
25 | GND | Ground |
26 | B5 | RGB signal cable |
27 | LCD_CLK | LCD clock |
28 | DE | LCD data enable |
29 | B3 | RGB signal cable |
30 | GND | Ground |
31 | B4 | RGB signal cable |
32 | G2 | RGB signal cable |
33 | G3 | RGB signal cable |
34 | GND | Ground |
35 | NC | GPIO interface |
36 | G6 | RGB signal cable |
37 | NC | GPIO interface |
38 | R2 | RGB signal cable |
39 | GND | Ground |
40 | R3 | RGB signal cable |