1.54-inch Display

• Video Tutorial

The Walnut Pi official 1.54-inch display uses the SPI bus with a maximum speed of 60MHz. The backlight is controllable, and the official driver supports system desktop display, PyQt5, and other UI functions.

The back features 3 programmable buttons, and GPIO pins are exposed via a patch ribbon cable connector, meaning that even when plugged into the Walnut Pi, you can still connect I2C, serial communication devices, and other modules.

Specifications
Resolution	240x240 (Pixels)
Interface	4-wire SPI (max speed: 60MHz)
Display IC	st7789
Operating Temperature	-20℃ ~ 60℃
Storage Temperature	-30℃ ~ 70℃
Dimensions	65x32mm
Weight	14g

• Pinout:

Pin No.	Label	Description
1, 17	3.3V	Power Positive (3.3V Input)
2, 4	5V	Power Positive (5V Input)
6, 9, 14, 20, 25	GND	Power Ground
18	LCD_DC	Command/Data Select, LOW=Command, HIGH=Data
19	SPI_MOSI	LCD SPI Data Input
21	SPI_MISO	Touch Panel SPI Data Output
22	RST	Reset
23	SPI_CLK	LCD/Touch Panel Clock Signal
24	LCD_CS	LCD Chip Select, Active LOW

Enabling LCD Display

The Walnut Pi system already includes the relevant display drivers, supported on both Desktop and Server editions. Use the following command to enable desktop display (supports TAB auto-completion):

sudo set-lcd lcd15-st7789 install

After configuration, reboot the board:

sudo reboot

Note:

You can also configure this by modifying the screen parameter in /boot/config.txt: screen=lcd15-st7789. config.txt Display Configuration Tutorial

Unplug the HDMI cable, wait patiently for the system to boot, and you will see the desktop interface on the LCD (Server edition displays the terminal), shown in the default orientation below:

Note

The above command works for both the Walnut Pi Desktop edition and Server edition (the Server edition will display the terminal). After making this configuration, if an HDMI display is also connected, the display will take priority. To show on the LCD, you must unplug the HDMI cable.

Setting LCD Display Orientation

Use the following command to set the display orientation, supporting angles of 0, 90, 180, and 270 degrees. The default is 270 degrees. For the Desktop edition, 270 or 90 is recommended, as portrait orientation can cause content to be truncated.

sudo set-lcd lcd15-st7789 set_rotate 270

Disabling LCD Display

Use the following command to remove the LCD display function and boot from HDMI:

sudo set-lcd lcd15-st7789 remove

Font Size Adjustment

Due to the small size and resolution of the 1.54-inch LCD, it is mainly used for terminal-based interaction (Server edition) or for PyQt5 experiments.

On the Desktop edition, you can open a terminal and use keyboard shortcuts to scale the terminal font for easier viewing:

• Ctrl + Shift + + : Increase font size

• Ctrl + - : Decrease font size