Dmitry Grinberg, like many people reading this, needed a holiday card. Many people would settle for something normal printed on cardboard, or even a “fancy” card with an audio chip embedded in it. This wasn’t good enough for Dmitry, and he instead decided to construct his own “card”, using a CD jewel case as the housing, that is able to play a full song in “full fidelity.”
The song that’s played is stored on an SD card, and is randomly selected from the card’s library every time the case is opened. Dmitry decided to make this “card” from components that he had around the house, since shipping can be unpredictable during the holidays. An ATTiny85 chip is used to select the song played, and a MOSFET-based amplifier cranks the sound up to a usable volume. Although it’s reportedly not the most energy-efficient design, a rechargable Li-Po battery ensures that beautiful music can be heard from this CD “case-player” for some time to come.
According to Dmitry, it’s “not the best designed or the most efficient, but it does work,” which I would call a resounding success. To me it looks relatively neat, since he decided to use soldered breadboards instead of having all his connections loose. Check out the video below to see it in action, and if you’d like to check out his code, it’s available here.
As originally seen on Hackaday.