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| I2S on Carambola2 https://www.8devices.com/community/viewtopic.php?f=13&t=858 |
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| Author: | franz1986 [ 29 Jan 2015, 08:51 ] |
| Post subject: | Re: I2S on Carambola2 |
| Author: | pepe2k [ 29 Jan 2015, 10:28 ] |
| Post subject: | Re: I2S on Carambola2 |
| Author: | franz1986 [ 30 Jan 2015, 11:12 ] |
| Post subject: | Re: I2S on Carambola2 |
Hi Pepe! As I'm also working on other projects I can not work fulltime on it, nevertheless I will start with the unificaton of the ar933x and ar934x driver. If it all works out well we can figure out what's needed to also integrate the QCA95xx SOCs. Thanks, regards, Franz |
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| Author: | Giedrius [ 30 Jan 2015, 15:18 ] |
| Post subject: | Re: I2S on Carambola2 |
| Author: | franz1986 [ 02 Feb 2015, 08:49 ] |
| Post subject: | Re: I2S on Carambola2 |
Hi Giedrius! Sorry for that, as I mentioned the driver is in a really "hacky" state at the moment. I will refactor it when I've got the time. I will test your change and apply it. BTW: I also do not have any codec, I verified the function of the driver via osci  Anyways, thanks for testing it! Regards, Franz |
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| Author: | jbubik [ 14 Mar 2015, 21:43 ] |
| Post subject: | Re: I2S on Carambola2 |
Hi Franz and Pepe, just a quick question (a bit off-topic): do you see it possible to (mis)use the I2S output of AR9331 as a generic data output? I am thinking of just I2S_CLK and I2S_SD signals (serial data and clock). You know bit-banging GPIO pins is so slow... With I2S output on AR9331 we could get theoretically up to 48kHz*512b=24,576Mbit!!! I may be wrong, but the bytes you send to the ALSA driver get sent unmodified over the I2S wires. If there would be a completely different peripherial instead of a wm8727 codec, it would get those bytes anyway, right? To be honest I am thinking of driving APA102 RGB LED strip (almost) directly from a cheap AR9331-based wifi router. If you are interrested about APA102 here is the datasheet: http://www.adafruit.com/datasheets/APA102.pdf 1) Do you see any substantial problems in this scenario? 2) From your experience, what would be the best class for a linux driver to write? Could be another serial-port driver? I really appreciate the work you've done so far. Jan |
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| Author: | valent [ 28 Apr 2015, 08:37 ] |
| Post subject: | Re: I2S on Carambola2 |
Can you please explain what is the next step? What do you mean by "codec"? Is codec just a software component or hardware? I understand that codecs are usually software components and they code and decode signals... but I lack deeper knowledge about how audio stack is composed. Which driver will you load in order to play audio? Can you just load some generic audio driver and make it play audio trough i2c output? |
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| Author: | jbubik [ 28 Apr 2015, 20:14 ] |
| Post subject: | Re: I2S on Carambola2 |
Hi Valent, the specific SoC has a built-in peripherial unit called I2S interface. It is NOT i2c interface (names are similar, but the signals are way different). The "codec" in this case is another chip that has I2S input (actually digital audio in raw PCM) that does DA conversion, amplification and so on. Is that clearer now? Jan |
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| Author: | valent [ 05 Jul 2015, 18:32 ] |
| Post subject: | Re: I2S on Carambola2 |
| Author: | aliaksei [ 24 Sep 2015, 09:33 ] |
| Post subject: | Re: I2S on Carambola2 |
How to connect wm8727 to Carambola2? I need electrical scheme |
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