MP3 Player Barely Larger Than An SD Card

If your board fabrication and soldering skills are up to it, you can make your own tiny MP3 player. This rendition is just about half again as large as a standard SD card, whose slot is on the bottom of the board seen above. The heavy lifting is taken care of by a VS1011 MP3 decoder which also has its own stereo headphone driver on-chip. There’s no display and it seems that most of the 4k of program memory on the PIC 18LF88 is being used. Too bad, we’d love to take this to the next level, attaching it to the head unit in a car and spoofing the communications as if this were a CD changer.

[via Hacked Gadgets]

45 thoughts on “MP3 Player Barely Larger Than An SD Card

  1. “Too bad, we’d love to take this to the next level”…. OK, then use a different micro? This site is supposed to be about hacking yet the write up seems to imply that modifying this design is not an option. Derp!

    There’s no display. Source code not necessary. The code for this is obviously very very trivial!

  2. It’s from 2006, now you would use an STM32F100 which has a smaller footprint, more IO, and 16K memory instead of 4… you can also EASILY use USB interface to dump songs so you don’t need an SD card reader.

    Very cool to have this as a starting point though. Mike, I know you’re a writer for HaD and not necessarily an EE, but if you could throw some info in like I’m posting it would keep the comments less cluttered/confused.

  3. What would be even cooler is to use a PIC32 as SD card reader, microcontroller and MP3 decoder. Those damn microcontrollers are now fast enough to decode their own MP3’s. They are cheaper and smaller than PIC with a VS1011. I have been playing around with the MP3 decoder, the source code can be found on the microchip website. Now to build my own Ethernet PIC32 internet radio. Might be interesting to use a PIC32 with build in Ethernet controller. All the functions you need in a 8 euro package. Can somebody lend me some spare time….

  4. @Ekaj well I didn’t look at the sourcecode but it says here that it takes all 4K so there must have been SOME effort done I figured.

    @tophat hackaday just got it as a new item on, which is not a bad site but not one that makes great claims, the guy running it just tries to keep some content coming in and there are some interesting things, and many articles arriving there are taken over by hackaday.

  5. I just use little wires for vias. You can file them flat if you need, and using this technique I put two 160 pin SMT board-board connectors on a two layer proto-router cut board that’s only 0.8″ by 4″.

  6. This is still pretty sweet. Like how they take the time to make it nice and small. And its a good bouncing off point for adding a display and more functionality. Not sure why HaD is worrying about the microcontroller.

  7. @Matt
    Haha, I usually do the same thing. I seem to have miles of old wire-wrapping wire left, that little wire is easy to strip and works great. I don’t think I’ll ever run out of that stuff. Does anyone else have that problem? I haven’t wire-wrapped in at least a decade, but the stuff still haunts me!

  8. Forget about the CD changer spoofing. Cram it into an old audio cassette and rig it up with a sensor on the drive sprocket that fast forwards and rewinds the MP3s (or skips tracks) when you press rewind or fast forward.

  9. The summary mentions the pic is a pic18lf88 — funny that, it dosen’t exsist.

    The actual pic being used is a 16lf88, in an 18-pin package. They’re very different devices, aside from one existing and the other not so much.

  10. A company called Blitzsafe makes AUX/MP3 to CD Changer adapters – One costs 80$ for my Acura TL!!!

    Its really smooth, double press the CD button.

    I would make my own for my Bose headunit! – the only problem is the headunit connector would be messy to tie in to with out the male plug.

    1. Looks like the English language to me. Although that term is a bit archaic, it’s still a legitimate one still. Not hard to figure out, or shouldn’t be anyway. Half of 10 is 5. 5+10 is not 20, clearly it doesn’t mean 2X. Kids these days ;) For many thinking in terms of “half again as large ” is easier to come up with a figure in their head than multiplying by 1.5, in their head. Before my stroke I used odd ways to calculate larger figures in my head, to get correct results. So odd there probably isn’t a way to phrase a description of them. Since the stroke I can’t rely on the results, so I refrain using my old ways.

  11. for an old, incomplete project that so many of you complain about it really started some interesting topics and led to a few nice tips of other chips and techniques. I think it was a successful post.

    And I enjoyed the post itself too. Thanks HaD.

  12. Why interface to the lame stock stereo in the car?

    Why not simply build your own stereo?

    This device rocks for a different use. make the pic trigger mp3’s based on input. I.E. a trigger-able soundboard. for animatronics.

    hook it to a car stereo.. how lame.
    Spend $99.00 and buy a frigging mp3 capable car stereo, that are all over the place.

    1. $40 buy you a Dual brand head unit that can handle a USB memory stick and a SD card up to 32 GB (I think) and also has an AUX analog input and FM radio. Put one of those in my old car. Beats the stock radio/cassette :P

      @OP nice hack anyways. I’ve been meaning to build one myself just for the challenge of it.

  13. Way too much feature creep. The goal of this was to make a super small MP3 player.
    Yes you could use a DSPPic to do it a different way. More power too you.
    You could use a slight larger cpu and then interface it to an iPod adaptor or your cars CD changer interface.
    But that is just it as a starting point.
    You could also use a larger CPU and interface it to an ATA/EIDE hard drive to make a really big ipod if you want.
    Or just got nuts throw on a radio chip, network interface, display, and an IR for remote control and make your own entertainment device.
    But this is a cool little start.

  14. What i would like to see is somebody making a new version of the MASplayer for amiga. there is currently NO mp3 decoding hardware available at retail for amigans to buy. only overpriced second hand mp3@64 and mas player pros and not very many of them!

  15. So since Alan Parekh does not publish the first comment on his site, here’s a copy:

    “Open Source Apple Shuffle like DIY MP3 Player”
    Not at all.
    No case
    No battery
    No USB
    No AAC
    MCU superfluous as VS1011 can work standalone

  16. When making halloween props, this would be useful to give them sound. Use a sensor (motion, pressure plate, etc) to turn it on and play, and make your halloween prop go rawararr!!! Have to find a way to make sure it ignores sensor hits for a short time so it has a chance to finish the sound effect + extra buffer.

  17. For small vias i use thin copper nails or rods.
    Make them a bit longer than the board is thick, and then i just give it a god whack with a small hammer.

    After a few practice vias you can get them almost invisble

  18. Forget about the CD changer spoofing. Cram it into an old audio cassette and rig it up with a sensor on the drive sprocket that fast forwards and rewinds the MP3s (or skips tracks) when you press rewind or fast forward.

    I tip my hat to you whoever you are.

    “The catflap! A device of the utmost cunning, perspicuity and invention. It is a door within a door you see.
    I think Dirk would agree with me, whilst not being a door, it has same level creativity.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.