[Xenomai-help] which skin to use

[Xenomai-help] which skin to use

[Łukasz Sacha]

Hi,
I'm working on a device that will process several input signals (2
analog, about 4 digital and 1 over serial interface) do some
calculations and control 4 uarts. It will also write some log data to
a file on an sd card.
It will probably be a single process working in an infinite loop,
regularly, say 50 times per second or more.
I'm a total beginner as it comes to RT and xenomai. I have some
experience in wrinting programs in C/C++ for linux.
Which API should do you think will be good for me to start with?
Which would be better for the application that I want to write?

Thanks,
--
Łukasz Dragilla Sacha

Re: [Xenomai-help] which skin to use

[Thomas Lockhart]

On 10/30/2011 03:47 PM, Łukasz Sacha wrote:
> Hi,
> I'm working on a device that will process several input signals (2
> analog, about 4 digital and 1 over serial interface) do some
> calculations and control 4 uarts. It will also write some log data to
> a file on an sd card.
> It will probably be a single process working in an infinite loop,
> regularly, say 50 times per second or more.
> I'm a total beginner as it comes to RT and xenomai. I have some
> experience in wrinting programs in C/C++ for linux.
> Which API should do you think will be good for me to start with?
> Which would be better for the application that I want to write?

I'd use the native API (others may have other advice, and I'd listen to 
them if so). If you write your program using regular Linux threads, then 
you can just add a few calls to convert the threads you need to be RT in 
userland.

At 50Hz you might be able to get by with the regular Linux version, 
unless you have very tight lag and jitter requirements. If you are going 
for kHz then afaicr Linux will just not be able to schedule your tasks.

You can write your code, do initial testing, then add some #ifdef 
XENOMAI lines to guard the extra Xenomai calls.

hth

                    - Tom

Re: [Xenomai-help] which skin to use

[Gilles Chanteperdrix]

On 10/30/2011 11:47 PM, Łukasz Sacha wrote:
> Hi,
> I'm working on a device that will process several input signals (2
> analog, about 4 digital and 1 over serial interface) do some
> calculations and control 4 uarts. It will also write some log data to
> a file on an sd card.
> It will probably be a single process working in an infinite loop,
> regularly, say 50 times per second or more.
> I'm a total beginner as it comes to RT and xenomai. I have some
> experience in wrinting programs in C/C++ for linux.
> Which API should do you think will be good for me to start with?
> Which would be better for the application that I want to write?

If you have programmed for linux, you know the posix api, so, using the
posix skin should be easy. The skins propose more or less the same
services, so, which skin you choose is a matter of taste, check the
doxygen documentation and choose the services you prefer.

-- 
                                                                Gilles.