Forums

Android vs Qt vs C/C++

Started by Zarakava December 15, 2011
On 21/12/11 01:06, Tim Wescott wrote:
> On Tue, 20 Dec 2011 22:15:21 +0100, David Brown wrote: > >> On 20/12/11 18:29, Tim Wescott wrote: >>> >>> Yes, you could do this on machine running Linux or VxWorks -- but your >>> total machine load (both memory and processor usage) would be something >>> like this: >>> >>> .----------------------------------------------.--------. | >>> | | | LINUX LINUX >>> LINUX LINUX LINUX LINUX | appli- | | LINUX LINUX LINUX >>> LINUX LINUX LINUX | cation | | >>> | | >>> '----------------------------------------------'--------' >>> >>> You _could_ do this, but unless your production volumes were really low >>> it's not going to pay back very fast. >>> >>> I'd do this with one of the many itty-bitty single-thread multitaskers >>> out there, like Micro-C/OS-2, or FreeRTOS, (or maybe ucLinux, but I >>> don't know enough about ucLinux to say). Or, like I said, I'd just do >>> it in a task loop. >>> >>> >> ucLinux is like Linux, except that it doesn't use an MMU. So all >> processes are in the same address space, and you can't do a traditional >> fork (you can do a vfork). However, you would still get the same >> picture as with "normal" Linux. >> >> Before considering Micro-C/OS-2, read the fine print of the license - >> it's quite expensive. I'm not suggesting it is /too/ expensive - it's >> up to the buyer to decide if it's worth the money. But people often >> think of it as a small low-cost system, because it is very low cost to >> try out, and get surprised by the final bill. > > The last time I specified Micro-C/OS-II, it was a $1500, one time fee per > board design (this was 10 years ago). The nearest competing "royalty > free" license was $30000 for roughly the same thing. I called it "quite > inexpensive". > > I forgot eCOS -- but then, I don't know how eCOS is fairing these days. >
I understood that Micro-C/OS-II required a fee per project, not per board design, and I believe the fee is quite a bit higher now. For a single project, that model will work well - and I'm sure that compared to other commercial RTOS's it is quite reasonably priced. But you'll quickly become concerned about the price if you have a lot of projects (but maybe there are site developer licenses, or something similar, also available). My point is not that it's a particularly expensive OS - just that people often think it is very cheap, free, or "free with the book".
On 2011-12-20, Tim Wescott <tim@seemywebsite.com> wrote:
> > I forgot eCOS -- but then, I don't know how eCOS is fairing these days. >
There's also RTEMS at http://www.rtems.com/ which is also open source. Simon. -- Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP Microsoft: Bringing you 1980s technology to a 21st century world
Le 21/12/2011 13:07, Simon Clubley a =E9crit :
> On 2011-12-20, Tim Wescott<tim@seemywebsite.com> wrote: >> >> I forgot eCOS -- but then, I don't know how eCOS is fairing these days=
=2E
>> > > There's also RTEMS at http://www.rtems.com/ which is also open source. > > Simon. >
FSL MQX RTOS could be an (free an lightweight ) alternative :=20 http://www.freescale.com/webapp/sps/site/homepage.jsp?code=3DMQX_HOME&tid= =3DSWnT Emmanuel
Thanks a lot guys for the suggestions.. Looking into it
>Le 21/12/2011 13:07, Simon Clubley a =E9crit : >> On 2011-12-20, Tim Wescott<tim@seemywebsite.com> wrote: >>> >>> I forgot eCOS -- but then, I don't know how eCOS is fairing these
days=
>=2E >>> >> >> There's also RTEMS at http://www.rtems.com/ which is also open source. >> >> Simon. >> >FSL MQX RTOS could be an (free an lightweight ) alternative :=20 >http://www.freescale.com/webapp/sps/site/homepage.jsp?code=3DMQX_HOME&tid= >=3DSWnT > >Emmanuel > >
--------------------------------------- Posted through http://www.EmbeddedRelated.com
For most embedded needs Linux is a little too heavy.

I recommend folks to take a look at Nuttx: 
http://nuttx.sourceforge.net/

This is POSIX and BSD licensed. May not support your chipset yet but the developer may help you port it.