Programmable MUSIC BOX

What is this?

Programmable music box is a “digitally controlled music box”. It provides the experience of a traditional rotary music box, musical notes are generated when a user turns it, however the user can choose what musical note to play through a digital interface. While the experience to the user is still a ”tangible” one, the programmable music box was intended to be a window into the digital world. 

What does it do? How does it work?

The programmable music plays musical notes with a set of pins striking against a note producing a musical note. It has a set of pins mounted on a cylinder, with each pin that can be retracted and extended under programmatic control. When an extended pin strikes the fixed gong (as the box is being rotated), the corresponding note is played. The sequence of the striking pins is controlled by the software selectable musical note.

What did I design?

Simply put, the music box is a set of programmable pins on a rotating cylinder. Each pin is driven by a simple linear mechanism, namely a solenoid. There were a total of 64 solenoids on the cylinder. The cylinder itself was coupled to a motor via a gear drive. 

The entire mechanical assembly was built from scratch to construct the music box. It includes

• press-fit assembly made from delrin on a waterjet,

• gear drive and motor assembly for the rotary mechanism,

• solenoids which were painfully wound and constructed by hand!

• and a mount to put this all together physically

I also put together:

• power circuitry to drive the motors and individual solenoids

  • for this, I designed and milled boards using an othermill

  • Assembled surface  mount components on these boards

• An AT Tiny micro-controller based control circuitry to 

  • receive inputs from a computer that related to the musical noteand

  • Drive the motor for the cylinder and 

  • synchronously strike the solenoid pins

What was the biggest challenge?

The biggest challenge in this entire project turned out to be mounting the control circuitry for the solenoids inside the cylinder. Since the solenoids each needed a logic line and power lines as they are being rotated (64 of them!), it was not obvious at first how to accompish this. It turns out there is a solution for this, a slip ring flange.

What’s next?

A user interface that translated a song into an music note that can be played on this music box is a logical next step.