Talk:Frequently asked questions/GPSstix and Audiostix2

From GumstixDocsWiki

Some comments on this page:

Perhaps the page should explain that the UCB1400 is the audio processing chip, which also contains 4 A/D conversion lines.

Some more information on the A/D conversion might be useful. According to the UCB1400 data sheet, the input impedance is 77 kOhm when the given input is selected, and full resolution input is 7.7 Volts if I understand correctly (the page says 4 A/D lines @ 3.3V which might be confusing).

The sampling time seems to be 81.4 ns (Tclk) * 21 = 1.7 us = 585 kHz in "Synchronized mode".

Also it would be useful to note that the A/D inputs are multiplexed (only one can be sampled at a time).

Can the GPSstix be used with only the Robostix?

Playback is very soft

I tried playing back a file using bplay, but the playback is very soft, almost inaudible. I've tried cranking up all the volume controls using aumix (-v100 -l100 -t100 -b100, if I remember correctly). What should I do to fix this? Should I try using amixer instead? Rol4 09:43, 24 October 2007 (PDT)