Re: [Gumstix-users] Quickest route to Audio w/out AudioStix

[Karl P. <kpi...@td...>]

--On 14 July 2005 10:48 -0400 Doug Sutherland <do...@pr...> wrote:

> Karl,
>
> I have the same problem of not being able to use audiostix, becauseI need
> the breakout-gs on the 60-pin connector for UART access. The breakout-gs
> board has the AC97 signals. I will soon be trying an external connection
> to audio codec to see how it works out. The difficulty is primarily the
> small packaging of the codecs (48-pin SMT LQFP).

Yeah, I didn't like the size vs. no. of pins either :)

> The UCB1400 is back in stock at digikey. I have also identified three
> others AC97 codecs in stock (LM4550, AD1881, AD1885). I'm planning to try
> different codecs to see how they compare. Also, one advantage of going
> external with the codec is you can add external mic preamp, amplifiers,
> tone control, etc. Once I have a proto of the audio features that works
> I will get a board made. This board could mate with the breakout-gs
> easily since there are not many signals to connect.

Sounds interesting :) - I know very little about AC97 - if you get an AC97 
compatible chip (i.e. any of the above you listed) - and hook that up to 
the AC97 signals, will the kernel driver 'just work' with it - or is there 
more to it than that?

Someone else I know suggested trying to go the i2c route - the only 
downside I can see with that is again, I know little about it - and I'd 
guess you'd need a kernel driver, or some user-space 'hack' to get sound 
out of it :)

-Kp