Archive for February, 2010

Arduino MP3 Rev B v0.0

Monday, February 15th, 2010

Last week I managed to have some luck with my Arduino MP3 shield. The big hold up was caused by not having enough power from the FT232RL chip to supply the decoder and the memory card at the same time (50mA max d-oh). I also had a software issue, I had not altered the code to deal with the 16Mhz clock speed of the arduino from the 8Mhz I was using on the ButterflyMP3 project. The SPI clock was running at 8Mhz where it needed to be slower than 6MHz (to comply with the VS1011E datasheet). Once I had that sorted everything just popped into place and started working reliably.

I apologise in advance for the poor integration of the library examples. I have simply and quite roughly ported the minimal parts of my buterflymp3 project over to the arduino and this hardware. The examples will test reading FAT16 file system on the MMC/SD card, test the VS1011E decoder chip, and play the first mp3 file found on the memory card. I hope to get these tidied up later but have not had any time to do so lately.

The PCB has not actually been tested yet so I’d hold off building a million of these until after a successful test. There is unlikely to be much wrong with it though as I have simply added a voltage regulator and re routed a couple of signals to fix my earlier mistakes. ( I’d forgotten that I/O lines 0 and 1 are used by the uart on the arduino)

I have embedded the BOM below. ( The bom is here if you don’t see it below)

Here are all the files so far. These are all released under a Creative Commons 2.5 license .

EAGLE files are here

GERBER files are here

Arduino Library files are here

PDF of the schematic is here

To use the library simply put the “mp3” folder from the zip file inside the “libraries” folder in your arduino folder (create one if it doesn’t exist). Restart Arduino 018 or later and you should have “mp3” entries in the menus under examples and import libraries.

The BOM references a 2.8V LDO voltage regulator but the schematic shows a 3.3V. Either will work fine but the 2.8 will give you slightly lower power usage.

If you are interested in PCBs or kits, drop me a line at
As always any comments, suggestions or ideas are welcome.