The LVGL 7.x that was integrated on NuttX had a calibration before initialize the demo, I think it was from LVGL itself.
There is also TS calibration that Greg created for TWM4NX: apps/graphics/twm4nx/apps/ccalibration.cxx BR, Alan On 5/23/23, Maciej Wójcik <w8j...@gmail.com> wrote: > It would be great if NuttX would offer calibration of touch screens out of > the box. > > I am not sure where it should go, but I think it could be a wrapper that is > used by many drivers. > > I think we have a similar situation with flash filesystems. There are > multiple layers that stack on each other. > > For example here there is `ftl_initialize` (flash translation layer) and > then `smart_initialize` (filesystem) > https://github.com/apache/nuttx/blob/master/boards/arm/stm32/stm32f103-minimum/src/stm32_w25.c#L266 > > Regarding the calibration itself, you probably know how to implement it, > but otherwise you might find this useful > https://gitlab.com/nxtlabs/shared-libs/touch-calib-lib/-/wikis/home > (explanation and implementation) > > Coming back to your question, how do other people do it? For me it was just > user-space code, part of the application. > > Am Di., 23. Mai 2023 um 20:12 Uhr schrieb Tim Hardisty > <t...@hardisty.co.uk>: > >> Hi, >> >> This is perhaps more a POSIX/general programming question than NuttX but >> you are all, so often, so very helpful :) >> >> A touchscreen peripheral (SAMA5D2 as it happens) delivers X and Y >> coordinates scaled 0-4095. >> >> LVGL wants them scaled to the actual size of the display (800x480 in my >> case). >> >> I'm not 100% sure that the chip’s TSD driver is the place to scale it? >> >> The TSD driver creates a generic /dev/input0 character driver, which is >> what LVGL (set via Kconfig) opens. Scaling within the LVGL code isn’t >> right >> either, I don’t think? >> >> I can only think of either: >> >> 1) creating a new character driver that does a translation – registered >> as >> /dev/input1 (or whatever) that LVGL uses, and this driver reads input0 >> when >> required and returns translated values. >> >> 2) Enhance the chip's TSD driver after all, using a Kconfig setting to >> enable X/Y scaling to the display's size (set in board-specific files >> already). >> >> Both seem a little messy though so perhaps I’m missing something obvious? >> Can't be the first to need to do this? >> >> Thanks, >> >> TimH >> >> >
