Any recent activity on this topic?

After long manual fiddling and copying I see now on latest git checkout (Linux Carambola2 4.1.13):

root@Carambola2:/tmp# aplay -L
null
Discard all samples (playback) or generate zero samples (capture)
default:CARD=Carambola2
ATH Carambola2,
Default Audio Device
sysdefault:CARD=Carambola2
ATH Carambola2,
Default Audio Device


Can this driver easily be built into the kernel compiling process instead of having to copy individual ipk files over, install and insmod them?

Nice....get sound from SPDIF....

Seems the headphone amplifier of my cheap SPDIF DAC is overloaded with sound peaked just under -2dB (o;

Have now some "sort of" volumio support with mpd on the module...

8% load for playing flac files (16-bit, 44.1kHz) and around 13% CPU load for playing 112kBits/sec internet radio..

Switching songs causes some noise to be audible...at least on SPDIF output...(no I2S DAC here yet ;o)

hi davorin,

so you used the SPDIF output as digital audio out?
was there some special configuration needed?
and what I2S chp do you plan to test?

sunny greetings
stefan

Hello Stefan

Yes I use the SPDIF output currently...was the fastest way as aI have a cheapo external SPDIF DAC for quick testing....

There was some additional bit to set in the GPIO configuration to enable SPDIF output (think it switches between JATG and APDIF) despite the fact that the source code says that SPDIF and I2S are enabled by default...

I haven't decided on the I2S DAC...but want to use one with I2C volume control...like the CS4349....but to test I2S I have some older DAC chips lying around somewhere (o;

Digged into Volumio a little this weekend...mpd works just fine...even playing 24 Bit 192kHz/sec sample FLAC audio via SMB keeps the CPU at around 50%...but the volumio web interface needs some further investigation as it doesn't use a regular http server...but some php-fpm process handling web front end and some backend worker process....but at least I can browse attached files and webradio stations and modify playlist on the Carambola2 development board...

Airplay is the next thing...but since it is in the 2.8 git repository...this should be no problem...

this sounds great

iam looking forward to here from your experiments

the idea somewehre back in my head is to use this as a base board for streaming flac or an other lossless stream thing. and in best case to have a virtual sound-card on the laptop as streaming server...
but currently there are some other projects to come first..

hi davorin,

my initial idea was to use the spi bus to stream data to a led controller...
this is only outputting data - but for a nice update rate i think i will get timing-collisions with the internal flash that sits on the same bus?!

so my question is do you think that it is possible to 'misuse' the I2S link to generate the data for my controllers?
currently iam planing to use the

I thought you want to stream audio files?

You won't have any luck with this TI chip as the timing and data amount is different from the I2S port....why don't you use a bit-banging GPIO method to control the LED driver chip?

i have multiple projects going on
one idea is to really use it for audio
and the other is similar to what has asked.. (found it just a minute ago )
i think that bit banging is to slow to get really nice smooth fades... (and that is the key requirement)
so that was the source for the idea to use the i2s lines...
i will read some more about this hole thing.. but i have the feeling it will get complicated..