Is the DMA channel dead?

Started by fralinux, May 07, 2015, 11:48:48 am

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fralinux

May 07, 2015, 11:48:48 am Last Edit: May 07, 2015, 11:56:32 am by fralinux
Hi everyone,
I buy the board IMX233-olinuxino-MAX from Olimex.
I copy the official image from IMX-Olimex Wiki (kernel 2.6.35) into the SD-card for the board.
I don't know how to check the audio line-in of the board!

After an:
[root@alarm ~]# arecord -f cd -D hw:0,0 -d 5 test.wav
Is the DMA channel dead?


Where is the problem?



Fra

mbergmann


fralinux

Hi Mike, thanks for all.

I have read only this, but I have linux kernel 2.6.35:
- https://www.olimex.com/forum/index.php?topic=704.0

Now, I try with the other topics and update you if there is news.
Thanks  :)

Fra

fralinux

Hi Mike,
I have found this topic:
https://www.olimex.com/forum/index.php?topic=3449.0

But no good news  :(


Please tell me how to do now?
Fra

mbergmann

Hi Fra,

I tried with my maxi and an image based on 2.6.35 (2.6.35.3_OLinuXinoR4) and it records by following benbiles instructions from the link you posted above.

Regards

Mike

fralinux

Hi Mike,

After an:
[root@alarm ~]# arecord -f cd -D hw:0,0 -d 5 test.wav
you have:
"Is the DMA channel dead?"

Tanks,
Fra

mbergmann

No, I do not have this message.

Btw: have you seen this: https://community.freescale.com/thread/319219

Regards

Mike

fralinux

Anyway, somebody can help me? :)
In the olinuxino i.mx233, it's possible to use audio codec without any problem? :( :( :(

Best regards.
Fra

mbergmann

Hi Fra,

the iMX233 is capable doing very descent audio using the build in feature set, which can be seen on the Audio Players using this chip, e.g. SanDisk Sansa Fuze+ or Creative Zen Fi series. They don't use a extra codec and are good players. If you want to have an idea how to program the SoC using bare metal check out the excellent work of Amaury Pouly. He ported RockBox to these iMX233 based players.

As you can see in the different topics on this board there are several problems with the audio implementation of the BSP and I don't think you will get a good Audio quality without putting some effort in it.

Unfortunately I can't say how good the Audio would be if you manage to sort out the current glitches. All I can say is that we had some problems doing a iMX233 HiFi design without external codec. It was a ton of work to eliminate the pops and chirps (the iMX233 seems to be a little 'touch me not'), so we decided to use a Wolfson codec in our second design.

Regards

Mike


fralinux

Hi Mike,

The Rockbox, is linux based, or pure embedded?

Regard
Fra

mbergmann

Hi Fra,

RockBox is pure bare metal, no OS involved.

Regards

Mike

fralinux

Hi Mike,
clear, is pure firmware based, without OS.

Thanks for all..  :)

For manage Wolfson codec, you use SPI or I2C?

Regard,
Fra

mbergmann

Hi Fra,

Our Codec is connected via SAIF (I2S) for the audio and I2C for the control interface.

Regards

Mike




fralinux