getting started at91sam7x512

koty0f wrote on Thursday, January 22, 2015:

Hello. I have trouble with running example for sam7x256 for eclipse. Im using eclipse 3.7.2, yagarto-20121222 and yagarto-tools-20121018. Board I have: ( Compiling seems OK. But the error LED is sensing some problem. I ran through modification demo guide and it seems its working too. But I cant connect to webserver. Even LEDs on ethernet port are not responding to connected cable. Im quite newbie in ARM so Im shure Im missing something elementary. With code I didnt do anything (even didnt change memory for x512, but I red on freeRTOS site that its not required if it can fit in 256KB). Any idea? Thanks

edwards3 wrote on Thursday, January 22, 2015:

If the code is running then its not a memory problem. I would guess the PHY used on your hardware is different to the PHY used by the original demo.

koty0f wrote on Thursday, January 22, 2015:

I checked pins to ethernet and LEDs and its OK. I forgot to write it… But you mean switch board.h file?

rtel wrote on Friday, January 23, 2015:

The demo you started with targets one of the EK demo boards. You are
using a different board. It is unlikely they are wired the same, or use
the same components, so it is likely you will have to update some of the
IO being used.


koty0f wrote on Friday, January 23, 2015:

Thanks for answers. It seems problem is understandign whole thing. Do you have some tip for good book, tutorial or material about programming arm, compiling and so?

koty0f wrote on Wednesday, January 28, 2015:

Has anyone some good book, website, anything where can I find foundation for programming embedded systems? How it works, description of used files (Makefile, .ld and so). Thanks

markwrichardson wrote on Wednesday, January 28, 2015:

I started my career programming for mainframes, databases and small systems, eventually moving to PCs. In those environments you only needed to deal with high-level interfaces to disk, display and printer. Relatively easy for new people to get started by writing/ready to each with small programs and you get results or errors with very little research.

I’ve always had an interest in electronics hardware but it wasn’t until 10 years ago I started working as a firmware developer, maintaining things that were already working. The environment is much less friendly because you have very few safeguards because some work requires talking to low-level devices with only the datasheet as a reference. Compiling and linking are still the same concepts, but the code you write doesn’t have an operating system as a layer to insulate you from crashing the system because of a mistake.

I’d recommend starting with a mature project board and load sample code that is known to be working and begin experimenting from there. I’ve recommended The Firmware Handbook by Jack Ganssle to a few new hires that are in the same boat. It gives a good overview of common issue and things to be aware of for a new embedded programmer. O’Reilly has a few books on embedded systems like Making Embedded Systems that would also give you a good overview.

Many issues are the same no matter what environment you use. Many more issues are different depending on the processor type that you use. Debugging a simple program interactively using a debug interface should be among your first tasks.

Many project kits have sites with users sharing experiences using that environment. Look for a popular one and read. There is a lot of information and learning involved with embedded development, so be ready to study for a while. True even if you are an experienced high-level programmer.

koty0f wrote on Thursday, February 05, 2015:

Thanks for advice:) It is my theme for bachelors thesis. So I have elementary knowledge about programming on any level. Im OK wiht learning new things, but still a bit lost in this. The structures of projects. What is each file about and so. But thanks for these books.

rtel wrote on Thursday, February 05, 2015:

These links may help: (out of date but still relevant)


koty0f wrote on Wednesday, February 11, 2015:

Thanks for reply. I red all of this. Now the scheduler is working. (I can run vStartLEDFlashTasks()) But whole demo is still sensing some error. I checked IOs and it seems its same with EK board.