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Read CD Audio with Stellaris.


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My next big project to to add a Digital Display Console to my 1994 Chrysler New Yorker.

It will have the following:

 

1. AM/FM/SW/Weather radio using Si4707 (Weather), Si473x-D60 (AM/FM)

2. Bluetooth Audio using  mRN-52 Bluetooth audio processor.

3. USB input (acting as host using host board).

4. GPS - need to decide which module.

5. 7" LCD touch panel using Vision Land Prestige 7L tablet with WI-FI. This is cheaper than doing 7" LCD from parts (and easier). Will use serial communication to tablet using serial debug interface.

6. CD Player?

 

Audio output will be to the existing Infinity Amplifier.

 

What I need to know is if anyone has interfaced to a CD/DVD drive to play audio? . I plan on using an old IDE CD player so I don't have to  mess with SATA. I can handle the IDE interface OK. I need to have some idea how to control and get audio off the drive. (I will be GOOGLEing when this msg is finished).

 

 

Thanks

John

Evil Minion

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If you have an analog audio input on your amplifier, I would just run analog audio out of the CD player (either from headphone jack on the CD player, if it has one, or from the analog out connectors on the back of the CD drive).  (Probably easier than handling the audio digitally.)

 

For control - you could drive the front panel buttons on the CD player electronically (would have to figure out what kind of signals run through the switches, whether could directly connect to digital outputs, or if need isolator/level shifter/transister/whatever.)

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Else you will need 16+ GPIOs to drive the data bus, RD, WR, CS, etc... http://en.wikipedia.org/wiki/Parallel_ATA

 

 

A digital audio stream is at least 44100sps * 2ch * 2bytes/sample = 176400 bytes per second that will have to be sent to an audio DAC via I2S.

This seems doable but not interesting.

 

You can still use the IDE interface to emit audio playback events (start, stop, seek) and read the TOC (track duration etc) but you'd better use a cd drive with an analog output. it was quite common in the IDE days. Some of them even have a TTL SPDIF output.

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igor

Yes I have inputs to the amplifier. I am going to mux the various audio sources.  I will probably use IDE to control the CD drive.  Now I just need to find a thin one that has audio output. Looks like another trip to Surplus Gizmos here.

squalyl

I have lots of experience interfacing IDE drives to micros. Should be no problems.  The RN-52 has lots of inputs, a DSP and even I2S.  https://www.sparkfun.com/products/11678. Yes I plan to use audio output from the CD. May use SPI and shift registers for the IDE.

 

However thing could get interesting for MP3 CDs.  Not to mention MP3 USB sticks.

However that is an optional addon.

 

Thanks All

John

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I don't think that PC CD/DVD drive is way to go. Today is not possible to find some good old devices (for example 8x CD-ROM Philips) that are still working OK. All new drives are spinning audio CD-s on much higher speed that is needed, and there are very nosy. If you really want CD, you can find some car multi-cd-changer drives without display, that have some "standard" (and open) interface for control from front panel. Another choice is to use CD car player, and break into interface on device front panel and use it for your customized control. I done this 10 years ago for Philips CD component, with reverse engineered original I2C for front panel keyboard/display control.

 

http://www.diyaudio.com/forums/digital-line-level/121352-old-philips-dac-module-info-required-6.html#post1835521

 

MP3 with SD card is more practical, and there are plenty of (open source) projects on net.

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