A DSP based Digital Audio (MP3) Player


1 May 2008 - DSPdap2 Schematics v0.1 released.

This is the first release of DSPdap2. It has the followign improvements over its predecessor DSPdap1.


  • Li-ion battery support with built-in charger (USB)
  • SD/MMC card support
  • Line-in recording and digitizing to SD card
  • SDRAM - more memory for more codecs and LCD
  • Small form factor (9cm x 5cm)

Download the Schematics.

26 April 2008 - DSPdap2 coming soon.

31 May 2007 - DSPdap released.

This is the first release.


DSPdap is a 'Do It Yourself' MP3 Player/recorder. DSPdap's hardware and software is open sourced to help you build you own DSPdap player or customize it as per your requirements.

DSPdap is different from other MP3 player projects because it uses a programmable DSP as its CPU instead of using a microcontroller + hardware MP3 decoder combination. Because of this, it is capable of playing not only MP3 but all popular digital audio formats (i.e. WMA, Ogg, RealAudio, etc) as and when the software is written to do so.


DSPdap has most of the features of a standard MP3 player.

  • MP3 file playback (Dual-channel and Joint Stereo MS/IS)
  • Compact Flash card for music and data storage
  • Operates on 1 or 2 AA/AAA sized batteries
  • USB pen drive functionality
  • High quality 24-bit stereo codec
  • Texas Instruments TMS320C55x 16-bit fixed-point DSP
  • FAT32 file system support

The features that can easily supported by writing appropriate software are:

  • WMA / Ogg / RealAudio support
  • Audio recording(either voice or high quality music)
  • Equalizer

Playback Quality - How good is it?

Hearing is believing. Below is a music clip that has been decoded on the DSPdap player. Download it and judge the playback quality for yourself.

Sound Sample
Download Sound Sample

The mp3 file used for decoding was a 320kbps, 44100 Khz stereo file. The clip is "Your Body is a Wonderland" by John Mayer.


DSPdap is not a simple project. It is not impossible to make though. Read and follow the procedures carefully. This is what you will need to build DSPdap.

  • Basic knowledge in electronics, microcontrollers and SMT (Surface Mount Technology) soldering
  • A lot of patience and dedication
  • You do not need to be a DSP programmer to build DSPdap. Firmware binaries and programming procedure is available
  • Basic tools like a SMT soldering gun, solder assist fluid, a PC with a USB port, a multimeter and a USB cable
  • Some cash, about $100. May turn out to be less or more depending on how easily you can obtain the PCB and the components

If you are a DSP engineer and are not keen on developing the board yourself, then we could try to support you with a fully assembled board.

If you are new at building electronic hardware then you should try looking at other projects listed below and judge for yourself which one is appropriate for you:

Even the above projects need some basic knowledge in electronics, microcontroller programming and SMT soldering.

If you still want to build DSPdap on your own then go ahead!! You will find all the resources you need to build it. Good luck!!