Hacking digital audio from car stereo - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 28th December 2013, 07:53 PM   #1
diyAudio Member
 
Join Date: Feb 2010
Default Hacking digital audio from car stereo

Hi all

So i'm trying to extract some digital audio from a particular car stereo. It's a Sony MEX-BT4100U (current 2013 model). It has input sources: AM/FM tuner, CD transport, USB media, Analogue AUX in and Bluetooth audio.

I've been picking through the service manual (https://docs.sony.com/release/MDSM/989355102_sm.pdf) and it appears that, typically, it's one big analogue switcher with modern digital bits bolted on.

Here's my interpretation of the block architecture for signal path:

Click the image to open in full size.


So my best hopes for anything pure digital from this unit are USB and/or CD audio. From what I can gather, the CD transport (DAX-25A), outputs a raw signal which the Sony ASE chip handles (it's described as a Head Amp).

It appears they have implemented a 32-bit ARM micro (!) mainly to handle USB comms/filesystem stuff. This seems to send audio digitally to the ASE/DSP chip using the 'BSIF' protocol. I was hoping for I2S but the datasheet for the MCU specifies multi-purpose ports, supporting I2S, SSP (SPI/Microwire) and BSIF.

Unfortunately I know nothing about BSIF and can hardly find anything about it on-line.

My goal is to get a clean digital output from either the CD transport or USB media source. I have a feeling the CD one would be very difficult. The USB option isn't looking particularly wonderful either. My logic analyser supports protocol definition for I2S but not BSIF.

Any thoughts on this folks?
  Reply With Quote
Old 31st December 2013, 10:45 AM   #2
diyAudio Member
 
Join Date: Feb 2010
Lots of views, anyone?
  Reply With Quote
Old 31st December 2013, 07:32 PM   #3
diyAudio Member
 
Join Date: Oct 2013
It's difficult to see what would be hackable, but in any digital audio system, you can always pick off the I2S data and clocks and plop that onto your physical DAC & analog stage.
  Reply With Quote
Old 5th January 2014, 08:19 AM   #4
diyAudio Member
 
Join Date: Feb 2010
Quote:
Originally Posted by logicform View Post
It's difficult to see what would be hackable, but in any digital audio system, you can always pick off the I2S data and clocks and plop that onto your physical DAC & analog stage.
Yeah, if only it were that easy with this one
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Dual 8" Sub for Home Stereo or Car Audio xpheolix Subwoofers 3 23rd October 2013 03:29 AM
any experience with car audio as a home stereo? gychang Car Audio 7 5th January 2013 01:14 PM
Car stereo home audio amplifier capcat Car Audio 8 25th April 2012 01:35 PM
Can I use regular stereo speakers for car audio? Racket Scientist Car Audio 10 30th May 2010 05:07 AM
Digital Amp for Car Audio? Livin Class D 9 1st July 2007 03:13 AM


New To Site? Need Help?

All times are GMT. The time now is 08:47 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2