Difference between revisions of "3.5inch HDMI LCD"

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{{RPI HDMI GPIO LCD FAQ}}
 
{{RPI HDMI GPIO LCD FAQ}}
 
{{FAQ|What are the power requirements?
 
{{FAQ|What are the power requirements?
|When working with 5V input, the current is about 200mA with back light on and 30mA with back light off.}}
+
|When working with 5V input, the current is about 500mA with back light on and 30mA with back light off.}}
 
{{FAQ|What is the operating current of 3.5inch HDMI LCD?
 
{{FAQ|What is the operating current of 3.5inch HDMI LCD?
 
| With 5V, the operating current of 3.5inch HDMI LCD is about 0.5A}}
 
| With 5V, the operating current of 3.5inch HDMI LCD is about 0.5A}}

Revision as of 11:13, 22 July 2019

3.5inch HDMI LCD
3.5inch HDMI LCD, 480x320, IPS
3.5inch-HDMI-LCD-1.jpg

480x320, 3.5inch Resistive Touch Screen LCD, HDMI interface, IPS Screen, Designed for Raspberry Pi
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Introduction

480x320, 3.5inch Resistive Touch Screen LCD, HDMI interface, IPS Screen, Designed for Raspberry Pi

More

Video

Getting Started

Hardware Connection

1. Connect the GPIO interface

Raspberry Pi leads out 40 GPIO pins, while the screen leads out 26 pins. When connecting, pay attention to the corresponding pins and Raspberry Pi pins.

2. Connect the HDMI connector to the HDMI port of the screen and the Pi.

3. Turn the Backlight on the back of the LCD to "ON".

Note: Raspberry Pi Zero / Zero 2 W needs an additional HDMI cable for connection.

The hardware connection is as shown below (Pi 4 and Pi 3B+):

3.5inch-HDMI-LCD-Manual-PI4B.jpg
3.5inch-HDMILCD-Manual-PI3B+.jpg

Software Setting

This LCD can support Raspberry Pi OS / Ubuntu / Kali / Retropie 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, and use SDFormatter software to format the TF card.

3) Open the Win32DiskImager 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, add the following code at the end of config.txt, then save and quit the TF card safely.

hdmi_group=2
hdmi_mode=87
#Display with 800*480 resolution
hdmi_cvt 800 480 60 6 0 0 0
#Use 480*320 resolution display, you need to add the following 3 lines of code
#hdmi_pixel_freq_limit=20000000
#hdmi_cvt 480 320 60 6 0 0 0
#hdmi_drive=1
dtoverlay=ads7846,cs=1,penirq=25,penirq_pull=2,speed=50000,keep_vref_on=0,swapxy=0,pmax=255,xohms=150,xmin=200,xmax=3900,ymin=200,ymax= 3900

5) Insert the TF card into the Raspberry Pi, power on the Raspberry Pi, and wait for more than 10 seconds to display normally. But the touch is abnormal at that time, and the touch needs to be calibrated as the following steps.

Note: Raspberry Pi OS Bullseye branch system, since dtoverlay=vc4-kms-v3d is loaded by default, it is invalid to modify the resolution in /boot/config.txt. If you need to modify the resolution, you need to change it to dtoverlay=vc4-fkms -v3d.

Touch calibration

The display can be calibrated via xinput-calibrator.

1. Execute the following command to install the relevant software:

sudo apt-get install xserver-xorg-input-evdev xinput-calibrator

If the execution fails, you can check #Some possible problems.

2. Execute the following commands:

sudo cp -rf /usr/share/X11/xorg.conf.d/10-evdev.conf /usr/share/X11/xorg.conf.d/45-evdev.conf
sudo nano /usr/share/X11/xorg.conf.d/99-calibration.conf

Add the following code to 99-calibration.conf:

Section "InputClass"
        Identifier      "calibration"
        MatchProduct    "ADS7846 Touchscreen"
        Option  "Calibration"   "190 3991 243 3895"
        Option  "SwapAxes"      "0"
        Option "EmulateThirdButton" "1"
        Option "EmulateThirdButtonTimeout" "1000"
        Option "EmulateThirdButtonMoveThreshold" "300"
EndSection

3. After reboot, the touch will work normally under normal circumstances. But for different resistance screens, the accuracy of using the default calibration parameters may not be very suitable.

You can perform touch calibration by clicking the Raspberry Pi icon on the taskbar, selecting Preferences -> Calibrate Touchscreen, and following the displayed prompts.

4. After calibration, the following data will be displayed. If you want to save these touch values, you can replace the data in the red circle with the data in the corresponding position in 99-calibration.conf. 5inch-HDMI-LCD-Manual-02-01.jpg

Screen orientation settings

Update software version

Raspberry Pi OS Bullseye branch needs to update the software version, and this step can be omitted for other systems.

sudo apt-get update
sudo apt-get full-upgrade

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

Ubuntu display rotation

First check whether the KMS or FKMS driver is loaded on the system you are using.

Check method: In /boot/firmware/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 methods for display rotation.

Note: For different versions of Ubuntu systems, the interface may be different. Generally, you can find the Displays application and rotate it.

GPIO-HDMI-Manual-01.png

GPIO-HDMI-Manual-02.png

GPIO-HDMI-Manual-03.png

Execute the command to rotate the Ubuntu login interface. If the Ubuntu login interface is not opened, this step can be omitted:

#For 32-bit systems, execute the following command, replace your_user with the currently logged in user name
sudo cp /home/<your_user>/.config/monitors.xml /var/lib/lightdm/.config
#For 64-bit systems, execute the following command, replace your_user with the currently logged in user name
sudo cp /home/<your_user>/.config/monitors.xml /var/lib/gdm3/.config
sudo chown gdm:gdm /var/lib/gdm3/.config/monitors.xml

Execute the following command to rotate the command line display during startup:

sudo nano /boot/firmware/cmdline.txt
#Add the following code at the end to rotate the command line
#rotate 0 degrees
fbcon=rotate:0 video=HDMI-A-1:800x480M@60,rotate=0
#Rotate 90 degrees
fbcon=rotate:3 video=HDMI-A-1:800x480M@60,rotate=90
#rotate 180 degrees
fbcon=rotate:2 video=HDMI-A-1:800x480M@60,rotate=0
#rotate 270 degrees
fbcon=rotate:1 video=HDMI-A-1:800x480M@60,rotate=270
No KMS or FKMS driver loaded

Rotation is relatively simple, just use the following command to display rotation:

sudo nano /boot/firmware/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

Add touch rotation parameter

sudo nano /usr/share/X11/xorg.conf.d/99-calibration.conf
#Modify the relevant command line in the 99-calibration.conf file, and it will take effect after rebooting the system. The following are the default calibration parameters. If you need to use specific calibration parameters, please pay attention to the order of the Calibration parameter values.
#touch rotate 0 degrees:
Option "Calibration" "190 3991 243 3895"
Option "SwapAxes" "0"
#touch rotate 90 degrees:
Option "Calibration" "3905 208 288 3910"
Option "SwapAxes" "1"
#touch rotate 180 degrees:
Option "Calibration" "3905 208 3910 288"
Option "SwapAxes" "0"
#touch rotate 270 degrees:
Option "Calibration" "208 3905 3910 288"
Option "SwapAxes" "1"

Interface

The pin marked as "NC" below indicates that the LCD is not occupied by the pin, and the user can use it for other applications.

Pin Number Identification Description
1 3.3V Power (3.3V input)
2 5V Power (5V input)
3 NC NC
4 5V Power (5V input)
5 NC NC
6 GND Ground
7 NC NC
8 NC NC
9 GND Ground
10 NC NC
11 NC NC
12 NC NC
13 NC NC
14 GND Ground
15 NC NC
16 NC NC
17 3.3V Power (3.3V input)
18 NC NC
19 TP_SI SPI data input of touch panel
20 GND Ground
21 TP_SO SPI data output of touch panel
22 TP_IRQ The touch panel is interrupted, and the low level is detected when the touch panel is pressed.
23 TP_SCK SPI clock signal of touch panel
24 NC NC
25 GND Ground
26 TP_CS Touch panel chip select signal, low level selects touch panel

Some possible problems

Touch jitter so obvious, how to solve it?

De-jitter parameters can be set to solve the problem of touch jitter, but at the cost of sacrificing a part of the sensitivity.

Since the ads7846.dtbo provided by Raspberry Pi by default has no de-jitter parameters, you can increase the de-jitter parameters by modifying and replacing ads7846.dtbo

Specifically, the anti-shake function can be added in the following method:

1. Execute the following command:

wget https://files.waveshare.com/upload/2/29/Ads7846_waveshare.zip
unzip Ads7846_waveshare.zip
cd ads7846_waveshare
sudo cp ads7846_waveshare.dtbo /boot/overlays/

2. Execute the following command:

sudo nano /boot/config.txt
#Comment out the following line:
#dtoverlay=ads7846,cs=1,penirq=25,penirq_pull=2,speed=50000,keep_vref_on=0,swapxy=0,pmax=255,xohms=150,xmin=200,xmax=3900,ymin=200,ymax =3900
#Add the following command at the end of the config.txt file, it will take effect after rebooting the system.
dtoverlay=ads7846_waveshare

Related reference documents:ads7846-overlay.dts ads7846.txt

The installation of xserver-xorg-input-evdev and xinput-calibrator in Ubuntu system reports an error, so the touch cannot be used normally. How to solve it?

Note: The Ubuntu system may not be able to access the default source due to network problems in some regions, resulting in an installation error.

Solution 1, update the source:

1. Execute the command to view the current version:

lsb_release -c -s

For example, after execution, the system version may be: groovy

2. Execute the commands:

#backup the original source
sudo mv /etc/apt/syntaxhighlights.list /etc/apt/syntaxhighlights.list.old
sudo nano /etc/apt/syntaxhighlights.list

Add the following code and save:

#If your system version is not groovy, please replace the following groovy with the version name obtained in step 1
deb http://old-releases.ubuntu.com/ubuntu/ groovy universe main
deb http://old-releases.ubuntu.com/ubuntu/ groovy-security main universe
deb http://old-releases.ubuntu.com/ubuntu/ groovy-updates main universe

3. Execute the command to update:

sudo apt-get update

4. After the update is complete, run #Touch calibration again.

If the above source fails, the following methods can be used:

Solution 2, directly find the download address of the two applications, download and install directly

For 32-bit systems, execute the following commands:

wget http://deb.debian.org/debian/pool/main/x/xserver-xorg-input-evdev/xserver-xorg-input-evdev_2.10.6-2_armhf.deb
sudo dpkg -i xserver-xorg-input-evdev_2.10.6-2_armhf.deb
wget wget http://mirrors.ustc.edu.cn/debian/pool/main/x/xinput-calibrator/xinput-calibrator_0.7.5+git20140201-1+b2_armhf.deb  
sudo dpkg -i xinput-calibrator_0.7.5+git20140201-1+b2_armhf.deb

For 64-bit systems, execute the following commands:

wget http://deb.debian.org/debian/pool/main/x/xserver-xorg-input-evdev/xserver-xorg-input-evdev_2.10.6-2_arm64.deb
sudo dpkg -i  xserver-xorg-input-evdev_2.10.6-2_arm64.deb
wget http://mirrors.ustc.edu.cn/debian/pool/main/x/xinput-calibrator/xinput-calibrator_0.7.5+git20140201-1+b2_arm64.deb
sudo dpkg -i xinput-calibrator_0.7.5+git20140201-1+b2_arm64.deb

The installation of xserver-xorg-input-evdev and xinput-calibrator in Kali system reports an error, so the touch cannot be used normally. How to solve it?

Note: The Kali system may not be able to access the default source due to network problems in some regions, resulting in an installation error.

Solution 1, update the source:

1. Execute sudo su to obtain administrator privileges. The default password is kali.

2. Execute the command:

wget -q -O - https://archive.kali.org/archive-key.asc | apt-key add

3. Execute the command to modify the source:

nano /etc/apt/syntaxhighlights.list

Comment out the original source and modify it to:

deb http://mirrors.ustc.edu.cn/kali kali-rolling main contrib non-free

Save and exit.

4. Execute the command to update:

apt-get update --fix-missing

5. After the update is complete, run #Touch calibration again.

If the above source fails, the following methods can be used:

Solution 2, directly find the download address of the two applications, download and install directly

For 32-bit systems, execute the following commands:

wget http://deb.debian.org/debian/pool/main/x/xserver-xorg-input-evdev/xserver-xorg-input-evdev_2.10.6-2_armhf.deb
sudo dpkg -i xserver-xorg-input-evdev_2.10.6-2_armhf.deb
wget wget http://mirrors.ustc.edu.cn/debian/pool/main/x/xinput-calibrator/xinput-calibrator_0.7.5+git20140201-1+b2_armhf.deb  
sudo dpkg -i xinput-calibrator_0.7.5+git20140201-1+b2_armhf.deb

For 64-bit systems, execute the following commands:

wget http://deb.debian.org/debian/pool/main/x/xserver-xorg-input-evdev/xserver-xorg-input-evdev_2.10.6-2_arm64.deb
sudo dpkg -i  xserver-xorg-input-evdev_2.10.6-2_arm64.deb
wget http://mirrors.ustc.edu.cn/debian/pool/main/x/xinput-calibrator/xinput-calibrator_0.7.5+git20140201-1+b2_arm64.deb
sudo dpkg -i xinput-calibrator_0.7.5+git20140201-1+b2_arm64.deb

Resource

User Manual

Driver

The driver can be downloaded from github

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

Image

3D Drawing

Demo video

Software

General Tutorial Series

FAQ

 Answer:
The LCD must have a driver installed for normal use. For details, please refer to the relevant introduction in the user manual.
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 Answer:
Since the Raspberry Pi image and version are frequently updated, if you encounter a situation where the LCD cannot be used normally, please download the latest version of the image provided by us or from the official website of Raspberry Pi and install the latest driver provided by us.
  • Make sure the hardware connection is correct and the contact is good.
  • Make sure that TF card programming is normal.
  • When the Raspberry Pi starts normally, the PWR light is always on, and the ACT light is flashing. If it is found that both lights are always on, it may be that the TF card is not successfully programmed to the image or the TF card is in poor contact with the Raspberry Pi.
  • It is recommended to use a 5V 2.5A power adapter for the Raspberry Pi. If the Raspberry Pi is powered by the USB port of the PC, the Raspberry Pi may not be able to start normally due to an insufficient power supply.
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 Answer:
Commercial grade (0~70 degrees Celsius).
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 Answer:
When working with 5V input, the current is about 200mA.
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 Answer:
When working with 5V input, the current is about 500mA with back light on and 30mA with back light off.
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 Answer:
With 5V, the operating current of 3.5inch HDMI LCD is about 0.5A
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Support

Support

If you require technical support, please go to the Support page and open a ticket.