7inch DSI LCD Screen

Features

• 800*480 resolution capacitive touch IPS screens
• Raspberry Pi MIPI DSI interface direct output, plug and play, no need to install driver
• Support for official system Raspbian, 2 points to zoom the page
• Support Ubuntu/Kali/Win10 IoT, single touch
• Support Retropie
• Backlight brightness adjustment button
• Support PWM backlight brightness adjustment, adapt to different use environment

Hardware Description

1）Backlight brightness adjustment button

For brightness adjustment, click to increase by 10%, then return to 10% after

reaching 100%; Long press to turn off the backlight and press again to restore

the original brightness.

2）MIPI DSI interface

MIPI DSI interface for connecting Raspberry Pi via FPC flexible cable

How to connect：

3）Backlight control mode selection
The circuit is used to choose the mode of fixed maximum brightness value or
the mode of adjusting brightness value through PWM：

• The 0R resistor is soldered to the right, then the maximum brightness value is fixed to control the backlight;
• The 0R resistor is welded to the left, then the backlight is controlled by adjusting the brightness value through PWM.

Note: The default option is to set the maximum brightness value to control the backlight

4）External PWM access point

Used for external PWM control signal input, you can control the screen

backlight brightness through the PWM signal. Where the PWM point is connected

to the GPIO (such as GPIO18) that outputs the PWM signal, and the GND point

is connected to the GND pin.

How to use

The module can be driven directly using the official original image without any
modifications.

Here are the steps to use the module on Raspberry Pi:

1. Download the latest system image from the official website of Raspberry Pi to the PC, and then extract the file to get .img file;(https://www.raspberrypi.org/downloads/)
2. Prepare a Micro SD card (at least 8GB), insert it into PC with the card reader, open SDFormatter software, select the target SD card, and then click the Format button to Format the SD card;
3.  After the formatting is completed, open Win32DiskImager software, first select Device (Micro SD card inserted on PC), then select Image File (decompressed. IMG Image File), and finally click Write for burning;
4. Pop out the SD card on the PC and insert it into the SD card slot of Raspberry Pi;
5. Install Raspberry Pi into the display module. First, install 4 copper columns to the positioning column , then use 4 screws (M2.5) to fix the Raspberry Pi to the copper column, then connect the DISPLAY module to the Raspberry Pi Display interface (J4 interface) through FPC flexible cable (5cm) , and finally connect the power cord to the Raspberry Pi;
6. Power up the Raspberry Pi, and you can see that the program runs normally. The module has display screen output, and the touch function is normal.

Note：

1. The copper column, screws and 15PIN FPC wiring are included in the product accessories.
2. Figure 4 shows the installation of Raspberry Pi 4. The installation method of Raspberry Pi 3 is the same as that of Raspberry Pi 4. The only difference is that the power cord connected is different. The Raspberry Pi 4 uses a Type-C cable and the Raspberry Pi 3 uses a Micro USB cable.

How to use PWM to control backlight brightness

• Adjustment by button: With each button press, the backlight brightness increases by 10%. The maximum increase is up to 100%, and then it starts cycling from 10% again. Press and hold for 3 seconds to turn off the backlight. After the backlight is turned off, a short press can activate the backlight.
• Adjustment by inputting commands: If a non-root user logs in, permission needs to be granted first (only needs to be run once after each startup).

          Then run:

where X represents any number from 0 to 255. 0 means the darkest backlight, and 255 means the brightest backlight.
(In this way, the brightness adjustment will be recorded in the system and still take effect after a reboot.)

Display direction rotation

There are two kinds of display direction rotation: FKMS mode direction rotation and traditional graphics mode direction rotation.

Method 1: FKMS mode direction rotation

FKMS mode is used by default on Raspberry Pi 4B.When using this mode, make sure that “dtoverlay =vc4-fkms-v3d” under pi4 in /boot/config.txt file is not commented out. In this mode, the display direction can only be rotated by menu options. Note that when setting the display direction in the menu, it is recommended to use the mouse for operation.

Method 2: Traditional graphics mode
By default, the Raspberry Pi 3, 2, and 1 series use traditional graphics mode. Raspberry Pi 4B can also use traditional graphics mode, just in /boot/config.txt file under the Pi 4:

Comment out (Traditional graphics mode is generally not recommended on Raspberry Pi 4B). In traditional graphics mode, this can be done by adding it at the end of the /boot/config.txt file:

To set the display orientation, reboot is required to take effect.

Touch direction rotation

The display direction is set, and the touch direction should be set accordingly. It
needs to correspond with the display direction, otherwise the touch operation is not accurate. Touch direction setting need to be in the /usr/share/X11/xorg.conf.d/40-libinput.conf file add "Option" CalibrationMatrix " " XXX" "content, including “XXX” for touch direction set parameters, the following will show
Open the 40-libinput.conf file:

After the modification, press Ctrl +X, Y, and Enter to save and exit. 

Corresponding relation table of display direction and touch direction:

How to install the virtual keyboard

Execute the following command: