Amulet, initial system test

A project log for Norman, Coordinate

The blinking, bleeping amulet from that Star Trek TOS episode.

peter-walshPeter Walsh 03/04/2017 at 06:110 Comments

Amulet is working, all that remains is to work up control button software (including debounce), and assemble the battery pack.

The original amulet was apparently a thin, vacu-formed clamshell piece with a seam around the sides and a mounting strip on the top. This is fine on camera, which wouldn't show the seam or clamshell, but it would look awful in real life. I decided to go with a hollow lasercut piece instead.

Also, the amulet of the original series had wires threaded through the chain making contacts with the hooks to the circuit inside the amulet. If you look closely, you can see the wires in the original episode.

Again, this is fine for on-camera work, but would look like crap in real life, so I decided to run the wires out the back of the amulet instead. The wearer can run the wires through a hole (or gap) in the costume, over one shoulder, and down the arm to the control box.

The original amulet had a dominant frequency of 1060hz, plus 2 lesser harmonics that gave it kind of "whistle" tone. The reproduction uses only the dominant, and sounds a bit "tinny".

Doing a proper reproduction would require storing and playing back the original tone, which the nano could easily do, but it requires a bit of electrical prowess (D to A conversion in some manner) that I didn't think was appropriate for a simple project.

Here's a video of the system in action: