nRF54L15 + ST7789 + LVGL bus fault

RE: nRF54L15 + ST7789 + LVGL bus fault

Toastus — Tue, 03 Feb 2026 02:43:20 GMT

A very useful question. Your setup helped me get mine working on a Xiao nRF54L15 with a 320x240 TFT. Here are a couple of tweaks to improve it and return the favor.

1) CONFIG_LV_COLOR_16_SWAP=y is not necessary on the ST7789v. It is only necessary on little endian configurations (which this one is), but there is a better way: let the display hardware handle the swap. The little endian bit is in the "ram-param" device tree setting. Change the [00 F0] to [00 F8] to put the display memory fetch in little endian mode and you can eliminate the swap code in LVGL.

2) The porch-params are disabled. You may see improved clarity if you turn them on by setting the center 00 value to 01. It worked on a 240x240 and on the current 320x240 despite display hardware differences.

RE: nRF54L15 + ST7789 + LVGL bus fault

PW — Mon, 29 Dec 2025 13:01:15 GMT

The solution is to add:

CONFIG_LV_Z_MEM_POOL_SIZE=8192

RE: nRF54L15 + ST7789 + LVGL bus fault

Vidar Berg — Tue, 23 Dec 2025 12:15:34 GMT

As ivan iushkov said above, a good first step is to run addr2line to find out where the fault occurred. Alternatively, you can start a debug session in VS code and inspect the call stack when the program has entered the error handler. Just remember to build the project with the debug options enabled.

RE: nRF54L15 + ST7789 + LVGL bus fault

PW — Tue, 23 Dec 2025 11:44:30 GMT

Situation when I commented all lv_ commands in main.c to simplify this case:

lv_string_builtin.c:151

And situation when code in main.c is executed:

lv_cache.c:56

It doesn't help me too much 😞

RE: nRF54L15 + ST7789 + LVGL bus fault

ivan iushkov — Tue, 23 Dec 2025 11:41:18 GMT

good first step to find the root cause is checking the faulty instruction.

You can find the following line in your log:

`00> [00:00:00.246,540] <err> os: Faulting instruction address (r15/pc): 0x0005c3b2`

You can try to run `arm-none-eabi-addr2line -e zephyr.elf -f 0x0005c3b2` to see the instruction triggered busfault, it can give you some hints on what happened