Luckfox Forums

Due to I have a general 40PIN LCD panel, and I check the LCD pin interface of PicoUltra. I found that PicoUltra is RGB666, but general 40PIN LCD is rgb888. It cannot be completely compatible to PicoUltra. However, the lower 2-bit color signal could connect to GND as default value. This makes it possible to design an adapter to a user defined LCD.
Expect hardware design, software is also important to meet new LCD. Through the checking of device-tree, 'display-timing' is defined in `sysdrv/source/kernel/arch/arm/boot/dts/rv1106-luckfox-pico-ultra-ipc.dtsi`. The directly method is to change display-timing in 'dts' file. But official SDK has the function of `luckfox-config`, user could set custom display-timing in cmd with the technology of `dynamic device tree`. This is pretty good to me for changing display-timing friendly.
Just for funny, I make a PCB to change PicoUltra LCD connector to general 40PIN LCD, and the result shows that it works well.
The following pictures show my test result: and the reference display-timing in `device-tree` is following:
display-timings {
native-mode = <&timing0>;

timing0: timing0 {
clock-frequency = <31000000>;
hactive = <800>;
vactive = <400>;
hback-porch = <88>;
hfront-porch = <40>;
vback-porch = <32>;
vfront-porch = <13>;
hsync-len = <48>;
vsync-len = <3>;
hsync-active = <1>;
vsync-active = <1>;
de-active = <0>;
pixelclk-active = <1>;
};
};

I suggest changing display-timing through `luckfox-config` cmd rather than `device-tree` modification.

TODO: Open source PCB.

Thank you for sharing, this is a good reference for users who want to adapt to more types of screens