Michael Thessel posts on Imgur about building an MP3 player for small children.
Final product first. This is an easy to use MP3 player for small children. I made this for my 2 year old for Christmas. Each of the top 9 buttons will play an album. The black buttons on the bottom are prev – play/pause – next. The player also supports an alternative playback mode that can be activated using a special key combination. That combination will turn the buttons into a 10 digit input matrix allowing playback of up to 99 albums. That way the player can be used by parents as well. 😉
The project was heavily inspired by Hoerbert: https://en.hoerbert.com Michael first saw the Hoerbert at a friends place. With a $400 price tag, why not spend 50 hrs and $100 to build ones own?
The Uno doesn’t have enough GPIO to handle 12 buttons, the volume pot, the Music Maker shield and UART as well. Because of that I added 2 shift registers that can handle 16 inputs and only need 3 GPIO pins to communicate with the Uno. In the picture you only see 2 buttons because at this point I didn’t have more buttons at hand.
See the entire project with lots of pictures here.
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