Arduino MP3 Project

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Hi there. This is my first post in this forum on top of being fairly new to Arduino so forgive me if I seem like a bit of a dunce.

Backstory-I am a professional photographer and also a graduate student in art school. I have built computers and high end stereo equipment. I am much more of a hardware guy than a software guy.

Project-I am in the process of making a book by hand. Hidden in the back of the book are two speakers. http://www.digikey.com/product-search/e … GF0661M-ND

I am trying to set the book up so that when the cover is opened a song starts to play. I only want one song so we dont need to deal with which song is going to play or for how long. At this point I was thinking the easiest way would be to put a photocell hooked up to an Arduino Uno in the hidden compartment. Then when the cover is opened, light hits the photocell viola!

Towards that end I purchased from SparkFun :wink: one of these https://www.sparkfun.com/products/10628

It has not arrived yet so not sure what if any trouble I am going to have hooking it up.

So that brings me to my questions…

  1. How should I power this??? It needs to be fairly small but I dont want to have to change the batteries every 5 min.

  2. Do I need to wire up a small amp to power the speakers or can I do that through the MP3 shield/UNO? (I have a sneaking suspicion that this is a really dumb question… :shhh: )

  3. I am sure I am going to have questions about coding this unless anyone has a project similar to this that I can modify pre-written code.

  4. Please feel free to answer any questions that I have but don’t know I have yet. :lol:

Thank you so much in advance

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baygrayhorse:
So that brings me to my questions…

  1. How should I power this??? It needs to be fairly small but I dont want to have to change the batteries every 5 min.

  2. Do I need to wire up a small amp to power the speakers or can I do that through the MP3 shield/UNO? (I have a sneaking suspicion that this is a really dumb question… :shhh: )

  3. I am sure I am going to have questions about coding this unless anyone has a project similar to this that I can modify pre-written code.

  4. Please feel free to answer any questions that I have but don’t know I have yet. :lol:

Thank you so much in advance

  1. While you might go with a LiPo battery, given the space you’re already needed for the electronics and speakers, I might go with a simpler solution like this:

https://www.sparkfun.com/products/552?#

… or one that uses 4 AAA batteries. How often do you expect the 1 song to get played ? My guess is not that often.

  1. If you use the speaker speakers above, you’ll need an amp of some sort. The MP3 shield is really only designed to drive headphone type speakers (90+ ohms) not the typical 8 ohm speaker.

While using a photo-cell to instigate the playback will work, that means you need a separate on/off switch to remove power. It might be simpler to use a microswitch to power on/off and then just code the system to playback upon bootup.

That’s going to be a pretty large book to fit all this stuff into. I assume you wanted a better than Hallmark greeting card quality of sound. Without having done the legwork to know for sure, I will say I think you could make a smaller system that plays just one song. There are other microcontroller (MCU) based designs that stored their sound in memory and played back through the MCU, no MP3 decoder needed. Perhaps something along the lines of this ??

http://hackaday.com/2011/04/25/single-c … io-player/

ps - not to invoke buyer’s remorse but did you see this ? It’s a more pre-integrated form of your plan.

https://www.sparkfun.com/products/11029

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Or perhaps this :

https://www.sparkfun.com/products/11125

Which supposedly can drive an 8 ohm speaker directly (though I suspect not very loudly)

FWIW : I mention the alternatives just to give you some food for thought but also when someone else thinks about the same thing, the references are there for them.