Home built MP3 player project - off the shelf chipsets? - Page 1
Forum section: electronics / projects

author: Corporate666
author_rank: Unknown
timestamp: July 28, 2014, 09:39:59 pm
content: An acquaintance of mine is investigating building a "juke box" type device for one of his corporate clients and had asked me about the electronics side of things.Reading a USB flash drive or SD card and playing the audio back through speakers is easy enough, but I was thinking that due to the huge # of such devices that exist, there is probably a simple to use chip (or chipset) in existence that would make this project quite simple... I've looked at the VLSI VS1003... but was wondering if anyone has personal experience with any particular solution and would recommend something?

author: TerraHertz
author_rank: Super Contributor
timestamp: July 29, 2014, 06:19:45 am
content: Quote from: Corporate666 on July 28, 2014, 09:39:59 pmThanks for the keywords VLSI VS1003.For years I've been using a couple of Thomson 6677 pocket players, that are OK, but have a few shortcomings. In the last few years I've been looking for something better, though nothing has turned up. So I too have been thinking about what I'd like in a pocket music player/voice recorder, but had only gone as far as writing out a list of features I'd like.There doesn't seem to be anything available that meets those requirements. Since I suspect one of the reasons for the glaring lack of a sensible pocket music player probably is related to DRM/copyright restrictions (spit), maybe it's time to roll my own.Did you look at the VLSI site, and see their other chips?This one seems impressive:http://www.vlsi.fi/en/products/vs1005.htmlThe old Thomson 6677 uses a Sigmatel STMP3510 chip. Googling that now turns into an interesting technology history lesson:http://en.wikipedia.org/wiki/SigmaTelIncidentally, if you're wondering what's so picky about my 'want' list, it includes items like:* Large replaceable battery, such as Li-ion 18650, for run time of months and no recharge down-time.* No god-damned 'music/genre database' or DRM bullshit whatsoever. Just a plain, fully transparent file system.* Simple plain-text playlists, or just play the files in selected folder in alpha-sorted order, showing filenames.* Pure USB disk interface, no requirement for drivers/software install on PC.* uSD slot for all play/record storage, compatible with largest current uSD sizes, and upgradeable for future sizes.Plus some stuff to do with screen size, font readability, controls, and how the record function works.Oh, and open source, updateable, hackable firmware.

author: Stonent
author_rank: Super Contributor
timestamp: July 29, 2014, 07:14:42 am
content: Older iPods used chips by Music and Wolfson. I'm not sure if they still make chips for that.

author: amyk
author_rank: Super Contributor
timestamp: July 29, 2014, 11:29:25 am
content: The VLSI chips are rather overpriced for what they do - for the price of asingle VS1003you can getan entire MP3 player with case, battery, and earphones.At the low end, these players are usually based on an 8051 or Z80 controller with a DSP for decoding; going up from there, the more featureful models will use an ARM or MIPS to do both control and decoding.I played around withs1mp3players when they were popular, those are an example of low to mid-range with a Z80+DSP.

author: SirNick
author_rank: Frequent Contributor
timestamp: July 29, 2014, 08:13:38 pm
content: The VLSI chips aren't bad for one-off stuff. Certainly not a cheap option if you wanted to release your own product. (But who would? That market is beyond saturated.) Modern micros are getting fast enough that real-time soft decode is perhaps on the table. I've been planning to look into that as an option for a standalone I2S-to-analog decoder that supports DD / DTS based on available source code, since the dedicated ICs to do that seem to be unavailable to hobbyists. HD audio codecs would be nice as well, but I haven't even started looking to see if those bitstreams can be pulled from HDMI without a black box IC.

author: Skimask
author_rank: Super Contributor
timestamp: July 29, 2014, 08:33:13 pm
content: I used a Sansa Clip, popped the case apart, hacked into the buttons, cheap Walmart headphone/speaker amp into the headphone jack, done and done, all driven with a simple Arduino sketch.Simple, cheap, works...

author: Kevman
author_rank: Regular Contributor
timestamp: July 30, 2014, 01:13:19 pm
content: I would imagine that these chips are becoming niche- modern MP3 players, even small ones like the Clip, use an ARM-based CPU and decode everything in software. Install Rockbox open source firmware on a Clip and it'll play pretty much any audio format- no DSP hardware required.You know, it'd be neat if you could just buy MP3 players that have Rockbox support like the Fuze and just modify Rockbox to do exactly what you want. The hardware would be already taken care of, then...