ble, lvgl, the prj.conf and RAM' overflowed by 3068 bytes error

RE: ble, lvgl, the prj.conf and RAM' overflowed by 3068 bytes error

ovrebekk — Fri, 12 May 2023 05:41:13 GMT

Interesting. The nRF5340 is also an option, with even more performance and memory. I will keep an eye out, could be fun to get one to play around with if a new version is made 🙂

RE: ble, lvgl, the prj.conf and RAM' overflowed by 3068 bytes error

lcj — Thu, 11 May 2023 16:13:29 GMT

I know another release is in the planning but have no purview into it. I expect 40 is a part of it.

RE: ble, lvgl, the prj.conf and RAM' overflowed by 3068 bytes error

ovrebekk — Thu, 11 May 2023 13:02:38 GMT

Hi Leo

It makes sense that the older versions would be leaner, if you don't need the features of v8.

A shame the PineTime doesn't use the nRF52840 though, then you would have much more memory available... (I am sure they had their reasons to use the nRF52832 instead)

Best regards
Torbjørn

RE: ble, lvgl, the prj.conf and RAM' overflowed by 3068 bytes error

lcj — Thu, 11 May 2023 10:27:54 GMT

Thank you! Looks like lvgl 8 is a lot bigger than 7. Some others working on the PineTime have stayed with 7 for this reason.

RE: ble, lvgl, the prj.conf and RAM' overflowed by 3068 bytes error

ovrebekk — Thu, 11 May 2023 07:25:00 GMT

Great to hear you got it to build 🙂

You might want to reduce the other parameter as well to give you a bit more overhead, depending on your application I am guessing you might need more RAM later when adding new features.

The memory report is indeed very useful. Especially the fact that you can click on elements in the report and jump directly to the implementation in the code, this allowed me to investigate which configuration parameters had to be changed to reduce the buffers.

There is also a search function if you want to search for specific modules (such as the calendar one).

[quote user="lcj"]Does it look like there are lvgl modules I should not have in there?[/quote]

Based on the screenshot I can't really see any superfluous modules, no. I wouldn't worry too much about unused modules, the linker should optimize them out if they are not referenced anywhere.

Best regards
Torbjørn

RE: ble, lvgl, the prj.conf and RAM' overflowed by 3068 bytes error

lcj — Wed, 10 May 2023 10:06:04 GMT

I did reduce CONFIG_LV_Z_MEM_POOL_NUMBER_BLOCKS to 6 and it did build. That's a great report. Lvgl is 56%:

Does it look like there are lvgl modules I should not have in there?

This forum is great! Thank you so much for this.

RE: ble, lvgl, the prj.conf and RAM' overflowed by 3068 bytes error

ovrebekk — Wed, 10 May 2023 08:57:55 GMT

Hi Leo

A very good tool to analyze RAM and ROM consumption in a Zephyr application is the Memory Report feature in the nRF Connect VSCode extension.

This provides a detailed overview of exactly which variables and modules are consuming how much memory, including a graphical representation of the various modules and how much they use:

In the example above I built the LVGL basic sample for the Adafruit 2.8" TFT display on the nRF52840DK.

The total RAM consumption is 178016 bytes, and from the memory report I can see clearly that most of this is caused by the LVGL display buffer (buf0) and the LVGL heap (lvgl_heap_mem).

The size of the LVGL heap can be reduced by reducing CONFIG_LV_Z_MEM_POOL_NUMBER_BLOCKS, which is set to 8 in the sample.

The size of the buffer can be reduced by reducing CONFIG_LV_Z_VDB_SIZE, which is a percentage value between 1 and 100 scaling the image buffer to the size of the screen.

I assume smaller values will lead to higher CPU usage and slower screen updates, but will reduce RAM consumption.

Best regards
Torbjørn