Display Support — GC9107, ST7735, ILI9341, Framebuffer

[felix]

Display Support — GC9107, ST7735, ILI9341, Framebuffer

Some OpenStick models have built-in displays, and you can also connect external SPI displays.

MF800B-E LCD — Built-in GC9107 Display
The MF800B-E LCD model comes with a 128x128 pixel GC9107 display connected via SPI. When properly supported by the kernel, it appears as a framebuffer device:

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/dev/fb0

Testing the Display
Quick test — fill the display with random pixels:

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cat /dev/urandom > /dev/fb0

Clear the display:

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dd if=/dev/zero of=/dev/fb0

Console on Display
You can get a text console on the display using fbterm:

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sudo apt install fbterm
fbterm

Note: The 128x128 resolution is very small for a text console, but it works for displaying status information.

Custom Status Scripts
Many users write scripts to display system status (IP address, signal strength, CPU temperature) on the built-in display. You can use Python with PIL/Pillow to generate images and write them to the framebuffer.

External SPI Displays
For devices without a built-in display, you can connect external SPI displays:

• ST7735 — 128x160, common and cheap
• ILI9341 — 240x320, larger display

You will need to wire the display to the SPI pins on the PCB and configure the appropriate kernel driver or device tree overlay.

Share your display projects in the "Show Your Setup" forum!