On 2023-05-13 06:46:51, jeremy ardley via Dng wrote:
> On 13/5/23 03:43, o1bigtenor via Dng wrote:
>
> Greetings
>
> (Is this OT - - - - dunno - - - that's why the goofy label!)
>
> I am in the beginning throes of an embedded system (SoC, and/or
> microcontroller) design.
>
> Have been reading somewhat on the use of RTOS vs and OS (thinking
> perhaps FreeRTOS and Devuan). My initial problem is a weighing 'cell'
> where I'm weighing liquids being deposited in a 'jar'.
> (A second would be items deposited (and then removed in stages) from a
> 4 wheel cart.)
>
> You only need to use RTOS etc when you are doing actions that require
> repeatable millisecond timings across multiple threads of execution and
> with hardware interrupts.
Linux has a RT kernel, I use it on my Devuan desktop for music
production. Did I bring this back on topic? B-)
> Even then RTOS etc aren't absolutely required. For instance ArduPilot in
> the original form doesn't have any form of RTOS and instead relies on a
> cooperative apartment threaded model where each function advertises how
> long it will take to run and a scheduler function calls each in turn based
> on time slots.
>
> For most use cases its easier to go the really simple route and use
> Arduino, or the slightly more complex route with a full Linux SOC using
> Raspberry Pi OS or Armbian or even Devuan.
>
> The only issue is Arduino is reliable with multiple I2C devices while the
> Linux derived systems can have minor problems where an I2C interface is
> done in software. Conversely Arduino requires a lot of effort on
> communication protocols of any complexity.
>
> An option can be to use an Arduino for low level control under command of
> a Linux based SOC board.
That's what I did for my last embedded project. Linux on the the SOC
board with the application written in C, and assembler on a PIC
controller for the hardware interface. The PIC could have been done in
C, but I decided assembler would be more interesting.
--
A big old stinking pile of genius that no one wants
coz there are too many silver coated monkeys in the world.