In case you're interested in the hardware on the board, there is an
ATmega 328p microprocessor
,
running Arduino software that pulls data from audio files on the micro-SD card and feeds that data
to the
VS1053B audio-decoding chip
. The VS1053B transforms the digital audio data back into
analog audio signals. The audio signals are sent to the headphone jack and a
TPA2016D2 stereo
amplifier
, which boosts the audio signal for the speakers. We also threw in a
MCP73831 Lipo
battery charger
to make it easy to recharge the battery from the FTDI port. Neat, huh?
Tips on speaker selection
The TPA2016D2 stereo amplifier on the LilyPad MP3 Player is capable of driving about a watt of
power into each channel. This doesn't sound like much, but it can produce surprising volume from a
large speaker.
In general, larger speakers will sound better than small ones, so use the largest ones that your
project will accommodate. Don't worry that the speaker is marked "20 watts" or higher; that is just
the maximum power that the speaker is designed to handle. We've had great results with recycled
automotive and PC speakers, and even large cabinet speakers.
If your project requires a small speaker, remember that any small speaker will sound much better if
it has an enclosed cavity behind it. You can do this with a project enclosure, recycled food
containers, etc. Use your imagination!
Some important things to know:
Always turn the LilyPad MP3 Player off before inserting or removing the micro-SD card. This
will prevent corruption of the data on the card.
The 5V FTDI port is provided to charge an attached Lipo battery, and provide a way to
reprogram the board. It will power the board if no audio is playing, but will not provide enough
power to drive the speakers (the board will reset while playing). In general, the best way to
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