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Example converting problem

M0NKA
Senior
Posted on October 17, 2012 at 17:36

Hello,

I am new to ST microcontrollers, just maybe 2 weeks ago I accidentally found about this

crazy chip (STM32F4) and now i am already playing with it.

I am interested in the I2S hardware and audio processing, so i first flashed the audio

example. All works fine, then installed Attolic and tried to compile, but off course was

not possible. So after lots of reading I have decided to use CooCox IDE.

All working and running, just have a problem with converting the Audio Playback

example to the CoIDE(MEDIA_IntFLASH configuration).

All files are added, dependencies fixed, so when the compiled image is flashed to the

board - the green led on start is ok, then the blue is blinking. The pause button works

as expected, also the MEMS sensor input is processed all right.But there is no sound

on the output.

The things i have suspected for the problem and i fixed:

- the SystemInit() call missing in the C startup file - done

- the correct value of the external cristal changed from 25 Mhz to 8 Mhz

- MEDIA_IntFLASH added to defines in the Configuration so relevant parts are

compiled

It seems next step is to add some debug print and go through init functions, attach

the scope, etc. But was just wondering if i am missing something obvious and somebody

has been there already and save me from hours debugging. Thank you!

BR, Chris
3 REPLIES 3
frankmeyer9
Associate II
Posted on October 17, 2012 at 17:51

You probably talking about the stm32f4_discovery board ...

I have never played with the audio chip on this board, but:

- First, it's a good idea to get the datasheet of this chip.

- Second, I2S is a synchronious bus, you should see clock signals at the according pins.

- Third: a scope is really recommended when working with a serial bus.

Atollic and Coocox are both Eclipse-based, which might have eased the porting...

M0NKA
Senior
Posted on October 17, 2012 at 18:07

Hi fm,

Thanks for the fast reply. Yes, sorry i was not clear. I am talking about the discovery

board. Right now there are no changes in the hardware, i just have the board and an

usb cable to flash images. As the pre-compiled code from the bin directory works fine

and both IDEs are based on the same compiler and similar configuration scripts, i was

expecting that would be easy to convert.

For my final project i would use probably TLV320AIC23B, this is why i didn't dig deep

into the pdf of  the chip soldered on the discovery board yet.

Yeah, i have a scope and a good logic analyzer also, right now i believe i miss some

compiler define or something, even i searched into all Attolic files and believe all is

done as it should be.

Regards
M0NKA
Senior
Posted on October 17, 2012 at 19:11

All fixed now.

For future reference, if somebody need this. After reading this topic:

http://www.coocox.org/forum/topic.php?id=756&page=4

The post from . It seems one of the CoCox file is wrong/incomplete/whatever:

so the Audio_playback_and_record\src\system_stm32f4xx.c needs to be inserted in

the CoIDE project instead of the automatically added one.

BR