Music Player - Feasibility ?

hippy

A question of feasibility and complexity before I invest too much time or effort ...

320GB IDE HDD + Propeller + PWM R-C DAC, Playing .WAV files

I currently have a $10 PC motherboard plus soundcard hooked up to play MP3's but want to replace that with something more 'embedded' - smaller, quieter, lower power, little cost outlay.

I can forego playing MP3 and use WAV as that would still allow 300+ albums to be stored, so this would really be a super-sized version of Rayman's SD Card WAV Player. Long filenames can be used to contain the necessary track ID Tag info set by a PC utility program copying files to the HDD, and/or 8-dot-3 files can be used with that info put into an index file.

Central to this would seem to be some sort of DOS ( preferable a Windows PC compatible file system ); anyone have an idea of how complicated that would be and what sort of development timescale would be involved ?

Mike Green

You could use Rokicki's SD card FAT file system as a starting point and just substitute the low level read/write drivers you'd need for your drive. A FAT file system would be the same on a HDD as an SD card. You'd have to format it using a PC and you could load it up initially that way as well. Rokicki's file system doesn't currently handle subdirectories, but that's not hard to add.

If you're in a hurry, you could use FemtoBasic as a starting point, rip out what you don't need and substitute a WAV player.

Baggers

Hippy, it should be pretty easy there's a great IDE interface here on a friend's website.
http://www.retroleum.co.uk/ide_interface.html
That should help interfacing the IDE to the prop [noparse];)[/noparse]
The rest should be easy, res+cap for audio, if using headphones, unless you want it amplified obviously [noparse]:)[/noparse]
As for timescale, depends how fast you get the code for the IDE interface working, I guess lol
A lot of the ground work can be taken from Rokicki's SD FAT drivers.

Should be easy enough to do though
But you'll have to keep us all updated lol.

Edit: Pipped to the post by the great·Mike Green Doh! lol

CJ

I think at that size drive you would have to do a fat32 driver as well, all the PCs I've used only format up to 2GB in fat16!

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Baggers

Yeah, good point CJ

Peter Jakacki

The hardware interface as shown by Phil Ruston is certainly something that you would want if you were using a Z80. Sure you could use it with the prop's I/O lines but the Z80 needed the interface and the prop can directly access the IDE with 23 I/O lines. I'm assuming that 3.3V drive is ok for an IDE interface although I've never tried it. Use series resistors of around 100R on all the lines plus add a pullup to the drive select line.

The 23 signals are D0..D15,A0..A2,CS0,RD,WR.

Yes, you will also need a FAT32 driver but I would build that up on the basic IDE sector interface which is very straightforward as the "Integrated Drive Electronics" pretty much looks after all the nitty-gritty, you just need to issue commands.

*Peter*

hippy

Thanks all. That IDE should be a straight-forward bit-banged interface from the Propeller is one of the appealing things, making the whole hardware project a couple of caps, a 40-way IDE cable and some buffering resistors.

Starting with a sector reader / writer would seem the best way to start and build up from there would seem to be the best approach as per Peter's suggestion. Even if the SD / Femto Basic code isn't directly usable it should be a good design reference. Can start with FAT16 then build on that.

It's the middle-bit, FAT32, which is the big unknown for me. Famous last words ... "That's only software, so should be easy enough"