Re: Linux support for a 7 segment LED display

From: Andy Shevchenko
Date: Fri Feb 23 2024 - 09:46:37 EST


On Fri, Feb 23, 2024 at 3:01 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> On Fri, Feb 23, 2024 at 1:36 PM Andy Shevchenko
> <andy.shevchenko@xxxxxxxxx> wrote:
> > On Fri, Feb 23, 2024 at 9:52 AM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> > > Note that most larger displays are not individual LEDs, but matrices
> > > of LEDs. Do we want to drive/scan them from software, using a
> > > gpio-7seg-matrix driver?
> >
> > LED matrices are the displays (like tinyDRM is for).
>
> TinyDRM is for rectangular matrices.
>
> Multiple 7-segment displays are usually multiplexed using a matrix,
> using 7 (or 8) lines shared by the corresponding segments of all
> displays, and one common line per display.
> https://embedded-lab.com/blog/wp-content/uploads/2011/03/Lab11_Circuit_SevenSegmentMultiplexing.jpg

Yes, that's what I call "dynamic" approach (in my translated
terminology, I dunno the proper English one). With this in mind, you
can read my message(s) above where I referred to it.

--
With Best Regards,
Andy Shevchenko