Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: The Natural Philosopher <tnp@invalid.invalid>
Newsgroups: comp.sys.raspberry-pi
Subject: Re: Pi Pico and Zephyr RTOS
Date: Sun, 12 Jan 2025 20:33:03 +0000
Organization: A little, after lunch
Lines: 52
Message-ID: <vm18tv$1da38$6@dont-email.me>
References: <vkf6lm$20vf2$1@dont-email.me> <vkfjpv$237di$1@dont-email.me>
 <vkgl7e$2bl1b$1@dont-email.me> <luigttF6mmpU1@mid.individual.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Sun, 12 Jan 2025 21:33:03 +0100 (CET)
Injection-Info: dont-email.me; posting-host="2f926649ad379acaad6b98eb2a7a7167";
	logging-data="1484904"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18xMnvlF7Atua7TIeZiCp/DuUGu1DPsTuI="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:N8LBpXcKhqpgx2nV1ruDLJ2usKU=
In-Reply-To: <luigttF6mmpU1@mid.individual.net>
Content-Language: en-GB
Bytes: 3255

On 12/01/2025 18:45, Brian Gregory wrote:
> On 25/12/2024 10:02, mm0fmf wrote:
>> On 25/12/2024 00:30, wmartin wrote:
>>> On 12/24/24 12:47, mm0fmf wrote:
>>>> Has anyone used the Zephyr RTOS on a Pi Pico or any other smallish 
>>>> system?
>>>>
>>>> I'm writing something relatively simple for a Pico in C using the 
>>>> SDK. It doesn't need an RTOS, the old classic cyclic executive 
>>>> paradigm will work fine.
>>>> At one time I'd have used an 8bit CPU but why faff about when you 
>>>> can get something like a Pico for hardly any cost even if 2x Cortex 
>>>> M0+ seems overkill.
>>> Well, you can have two threads, kinda, with the Pico without an 
>>> RTOS...just split your work between the two cores. I just did a 
>>> simple project using one core to do a com link to a pc for 
>>> command/response, and the other core to do a real-time hardware 
>>> controller chore. Made it painless...
>>
>> That was my plan. The project has to do simple things like scan a 4x4 
>> keyboard, light assorted LEDs and send strings over the UART at 38k4 
>> to control something. I'd already decided that I would run all the 
>> UART send/receive on one core and run the control on the other core. 
>> That way the control core remains non-blocking and the UART core can 
>> block if needed.
> 
> Doesn't the PICO SDK include some FreeRTOS examples?

It does. If You cant live without a pre-emptive multtaskking solution

> 
> Do you really need Zephr RTOS rather than FreeRTOS?
> 
> Note though, that I'm not sure if the examples have the ability to use 
> both cores yet, I remember that initially they just allowed 
> multi-threading using a single core on the PICO.
> 
> If it was me I think I might just write my own RTOS that worked the same 
> way I was originally taught to do multi-threading (using Dykstra's 
> semaphores and not much else) rather than having to learn and understand 
> how somebody else thought it should be done.
> 
+1 for that.

-- 
I would rather have questions that cannot be answered...
....than to have answers that cannot be questioned

Richard Feynman