Application note sharing: Issues often met in i.MX28 application

[#1]

In Chinese Twitter: Sino Weibo, one famous distributor mentioned “i.MX28 is the best choice in ARM9 core-based processor, no ‘one of’”. With high integration of analog module and digital module, i.MX28 is attracting more and more engineers in various applications. Despite its advantage, there are some mistakes one may commit or issues they may meet. The note records a number of issues/mistakes. Each case in the note comes from a real story.

I hope the note will help you in your development work. And It is definitely welcomed for everyone to add your own content to the note.The more you share, the more you get.

[LeonardoSandova]

Nice Document!

[samsaprunoff]

I agree.  The imX28 is a fantastic processor and has a great price point.  The only disappointing thing is that Freescale has seemingly lost interest in providing more of an i infrastructure for this processor.  I say this, as compared to the additional resources in the Coldfire and Kinetis family, the iMX family pales in comparison.  From my viewpoint I see that most of Freescale's iMX Group support efforts are towards Linux, as opposed to anything else...This in itself is not a bad thing, but a lot of of embedded applications are not well suited to the complexities of using Linux (i.e. tools, kernel, file system, etc)...

Anyway, thanks again for the document!

Cheers,

Sam

[StanleyLee]

Yes, your actually raised a common question. Fortunately, we prepared other options for i.MX28, like MQX, WinCE and OBDS. I especially recommended OBDS because it is a non-OS driver set, in which you can directly access i.MX28 internal modules. And all the resources are available from Freescale official website.

[LeonardoSandova]

Hi Sam,

you are right, Linux is complex and takes time to grasp it. Sometime ago I bough this http://www.amazon.com/Embedded-Linux-Primer-Practical-Real-World/dp/0131679848 book, and as an introductory book for Linux at embedded devices is the best (at least for me)!

[samsaprunoff]

Good day Xingyu,

Indeed there are other options for the imX28... however, there are issues with each of these....  MQX has to be purchased and last I checked was about $20K USD...  WinCE is also has issues (not very deterministic) and also requires licensing.  OBDS is very helpful and does provide some low level "guidance", however, it is not nearly as comprehensive as to the samples available on the Kinetis and Coldfire families.  Frankly, I just find it odd that Freescale would have such a huge discrepancy in bare metal applications between the iMX and their other MicroController families.  Like I said I really think the IMX28 is a fantastic processor/microcontroller on all accounts, but the effort to use it in bare metal applications is not for the faint of heart.

Cheers,

Sam

[samsaprunoff]

Good day Leonardo,

Thank you for your book recommendation!  I already have it!  ... and a few others too!

The issue I have and maybe it is just me... is that for as much as I like Linux I just do not see it as the best solution for a number of applications (i.e. real time response used in controls, communications, etc).  Secondly, because of Linux's complexity (i.e. bootloader, kernel, etc) there is an inherent risk of reduced reliability.  This is by no means a slight against Linux, but the fact that adding more complexity increases the probability of issues.  As for embedded Linux's learn curve... yikes... I am still learning despite the number of books/app notes I have read, the number of courses I have attended, etc... and I still do not feel comfortable embarking on a time sensitive project with it.  For example, there are a number of issues just getting your basic system up and running (i.e. have a fully working development and debugging platform)...From the bootloader (U-boot is almost an O/S in itself), to the Kernel, tools, file system, etc...  Indeed, there is a large time investment here...In comparison to Kinetis, Coldfire, etc... one can take one of the many Freescale's Kinetis/Coldfire,application examples and very quickly have a development environment up and running as well as have the core system functionality working... one can do this in all of about 2-3 hours...  I wish Linux was as straightforward ...  Like I said, maybe it is just me...

Anyway, I have not given up on the iMX28 or Embedded Linux and still try to ramp up on as time permits and I appreciate Your, Xingyu, and other poster's comments as they are very helpful to us on the sidelines!  Thanks again!

Cheers,

Sam