How do I go about picking an architecture ? My first thoughts suggested Cortex M3 but the more I look into it the less sure I am.
Obviously I don't to go to the trouble of learning a new technology only to find that I've made a bad processor choice (ie nearly end of line). I've spent many hours looking at many websites and have yet to find any high-level stuff on choosing my first ARM device.
If there's one thing wrong with ARM its the almost infinite number of devices
I'm an embedded developer wanting to undertake my first ARM project, so I'm completely new to the ARM architecture. I want a low power device with serial, USB and some ADC channels.
Per did use the word, "dangerous".
But I don't think he was talking (particularly) about hazards to persons or property - I think he was talking about business risks.
As in, "there is a danger [business risk] that not having the source code may leave your project/product high & dry"
I think.
"I think he was talking about business risks."
nice try. I would give you an F for effort.
so Andy, you are conceeding on that the two other fronts (performance and stability), Per didn't think using OEM libraries would have adverse effect? could you work that out with tamir? :)
"As in, "there is a danger [business risk] that not having the source code may leave your project/product high & dry""
so it would not have any adverse impact on "SAFETY" (aka business risk) if you have access to the source code?
does that make it OK to use the Luminary libraries? could you please work that out with Per? :)
This thread quickly evolved into a kindergarten brawl, for no apparent reason.
Why should I be required to give examples to something I'm not claiming?
The probability of bugs is similar whoever wrote the code. A much used library from a manufactuer should - hopefully - be reasonably well-tested by all the users.
But I was talking about the business risks of using a library you don't have the source code - and suitable license - for.
With the source code, you can perform security reviews, looking for buffer overflows, resource leaks...
With the source code (and most licenses), you can correct bugs without need to wait for a new official release, and without worrying about the supplier vanishing.
With the source and a suitable license, you can not only fix any bugs, but also move the complete source code to new platforms.
Since a chip manufacturer isn't likely to supply general libraries with full source and BSD, LGPL or similar licenses, you should be very careful about using them. You may end up with a very serious nose bleed.
The CRTL can also be a bit problematic, but the advantage with the CRTL is that there exists a large number of suitable licensed C runtime libraries, so a company can replace printf(), strxxx(), time(), ... with alternative implementations without having to start from scratch, as long as the target has some safety margins in case the alternative implementation takes more code space, RAM or executes a bit slower.
With the source code (and most licenses), you can correct bugs without need to wait for a new official release, and without worrying about the supplier vanishing. A ticket machine was violating the J1708 protocol and created many errors on the bus. When the manufacturer was approached they, of course, replied "no such thing". After being shown proof they stated "this will be fixed in the next release out in October next year (my emphasis).
Erik
"Why should I be required to give examples to something I'm not claiming?"
sounds like you are unclaiming what you just claimed. what do you think this guy/gal was claiming when s/he said:
"For commercial use, you should have full access to the source code, and a license that allows you to run the code on _any_ processor, even if different manufacturer or non-ARM architecture."
no answer is required, :).
So, I give you an F for your reading skills.
Where did the following text explicitly mention that you should use OEM libraries with generous licenses?
The above text indirectly says that you should look for _general_ libraries and _stay_away_ from manufacturer-supplied libraries.
This was further strengthened if you had also quoted the sentence directly above: "It is always very dangerous to make use of manufacturer-specific libraries."
That is a good reason why it is quite strange that you require me to supply examples of OEM libraries with LGPL, BSD or similar license even if such examples does exist.
If I should supply examples to my claims, then it woould be more reasonable to expect examples of restricted licenses common with manufacturer-supplied libraries - not examples of free manufacturer-supplied libraries.
Do you often expect people to back their claims by examples that are negating the claims?
... some young whippersnapper SHOUTS "prove it"
If we can not share our experience whithout being "taken to court" then some of us will need to start charging (which we do when required to 'prove')
'Where did the following text explicitly mention that you should use OEM libraries with generous licenses?'
why should I defend a question that I didn't ask?
you get F for your reading comprehension.
'If we can not share our experience whithout being "taken to court" then some of us will need to start charging (which we do when required to 'prove')'
you sure can share your experience whenever you want. That doesn't mean that others have to take your experience at face value.
if you cannot stand the heat, you should probably stay out of the kitchen.
woman, you have an attitude! yuk! :-)
"why should I defend a question that I didn't ask?"
So you don't even understand your own posts?
"if you can provide a few examples where an OEM library can be legally run on other manufacturer's chips, I am happy to see that."
is it less than truthful if the whole discussion has been able the use of OEM libraries - I am the first person mentioning that and you follow right up with your "commercial library" concept, which the OEM libraries are a subset of it.
now, you are saying that you followed up in a thread about the use of OEM libraries so you can talk about the use of non-OEM libraries that allow you full source code access, of which you can find none?
so you are essentially suggesting that we should use libraries that do not exist?
????????????????????????????????????????
is this some kind of mind trick?
Good writing practices says one or three punctuation characters. Not two. Not more than three. But then sentences are expected to start with a capital letter.
Do read my post again. I warn aganst the use of manufacturer-specific libraries or any other kind of libraries, where you do not have full control. And full control includes access to the source and a license that allows you to use it.
I have never once said that manufacturers likes to give out their libraries with full source and carte blanche licenses. But I have claimed that the main reason for such libraries is to bind you harder to their products.
The only trick involved is a trick often used by the manufacturers. If you are going to use a manufacturer-supplied library, you should at least do it with your eyes open!
The ARM chips are powerful enough that you can most of the time have very good separations between hardware and business logic. When you design all of the code, you can be very careful about where to place this separation. When using a manufacturer-supplied library, you will instead end up having your business logic littered with copyrighted function calls. You can't just rewrite the library implementation if you try to move to another processor, because you need to match the original function prototypes - and the original header file is copyrighted...
"I have never once said that manufacturers likes to give out their libraries with full source and carte blanche licenses. But I have claimed that the main reason for such libraries is to bind you harder to their products."
Now I use my MCU vendors brain: Creating the libraries often involves many man years of coding, so why giving it away to be used by competitors. Why would you not want to try binding customers to your chips if at all possible. That is viable business practice as long as you help your own customers.
Switching brain to MCU user: It sucks to be stuck with one vendor, particularly using ARM where it would be rather easy to switch from A to N to S or T. So if I find a real open source I will probably go for that one.
Impair, an attempt: If you find what you are looking for with one vendor and the chips do what they should and the price is right, don't argue, go for it and get work done.
Cheers, Robert For the original poster there is a site that gathers articles related to Cortex-M mcu-related.com/.../35-cortex-m3
"Do read my post again. I warn aganst the use of manufacturer-specific libraries or any other kind of libraries, where you do not have full control. And full control includes access to the source and a license that allows you to use it."
more precisely, where you *MAY* not have full control of the source code. the Luminary library is a good example.
nobody said that you said that, so let's move on.
your point about avoiding OEM libraries is a good one, and nobody is arguing against it. because the lack of portability introduced by OEM libraries can be too great: those libraries typically forbid the porting to a competitor's chips.
the reasons given in support of such an argument, needing full source code access on a commercial package, security (?), performance and stability, are bogus at best.
however, I do see advantages of using OEM libraries: the code is generally of higher quality than a novice programmer can generate and it gets one going quickly. so if a corporation has made a commitment to a platform / vendor, it can be advantageous to use oem libraries.
but a thorough analysis needs to be done before committing one to such an approach.