# Jack-o-Theremin
## Overview
## What is a theremin?
A [theremin](https://en.wikipedia.org/wiki/Theremin) is an electronic musical instrument that you can play without even touching it - spooky! The theremin senses the distance from its antennae to the player's hands, and changes its pitch and volume based on these distances. The theremin was used to make soundtrack music for many iconic spooky movies, like The Day the Earth Stood Still (1958), and is perfect inspiration for a Halloween project!
Here, I've turned a pumpkin into a Jack-o-Theremin using an ultrasonic distance sensor and a Circuit Playground Express (CPX). The CPX uses the distance measurement to generate a sound and flash the onboard NeoPixels in various colors. This version of a theremin has a much more digital-bleepy-bloopy sound than a traditional theremin, but you still get to make music by waving your hand around in the air!
## Materials
You'll need:
Featured
### Circuit Playground Express
[Circuit Playground Express](https://www.adafruit.com/product/3333)
**Circuit Playground Express** is the next step towards a perfect introduction to electronics and programming. We've taken the original Circuit Playground Classic and made it even better! Not only did we pack even more sensors in, we also made it even easier to...
Out of Stock
[Buy Now](https://www.adafruit.com/product/3333)
[Related Guides to the Product](https://learn.adafruit.com/products/3333/guides)
Featured
### HC-SR04 Ultrasonic Sonar Distance Sensor + 2 x 10K resistors
[HC-SR04 Ultrasonic Sonar Distance Sensor + 2 x 10K resistors](https://www.adafruit.com/product/3942)
If you're like me, you've dreamed of being a dolphin - smoothly gliding through the water. Using your echo-location abilities to detect tasty fish treats. Until genetic modifications catches up with our desires, we'll just have to make do with these handy **HC-SR04 Ultrasonic...**
In Stock
[Buy Now](https://www.adafruit.com/product/3942)
[Related Guides to the Product](https://learn.adafruit.com/products/3942/guides)
Featured
### 3 x AAA Battery Holder with On/Off Switch and 2-Pin JST
[3 x AAA Battery Holder with On/Off Switch and 2-Pin JST](https://www.adafruit.com/product/727)
This battery holder connects 3 AAA batteries together in series for powering all kinds of projects. We spec'd these out because the box is slim, and 3 AAA's add up to about 3.3-4.5V, a very similar range to Lithium Ion/polymer (Li-Ion) batteries and have an on-off switch. That makes...
In Stock
[Buy Now](https://www.adafruit.com/product/727)
[Related Guides to the Product](https://learn.adafruit.com/products/727/guides)
Featured
### Mini Metal Speaker w/ Wires - 8 ohm 0.5W
[Mini Metal Speaker w/ Wires - 8 ohm 0.5W](https://www.adafruit.com/product/1890)
Listen up! This tiny 1" diameter speaker cone is the perfect addition to any small audio project where you need an 8 Ω impedance and will be using 0.5W or less of power. We particularly like this cone as it's very simple and its metal body is extremely lightweight.
Out of Stock
[Buy Now](https://www.adafruit.com/product/1890)
[Related Guides to the Product](https://learn.adafruit.com/products/1890/guides)
Featured
### 2-pin JST SM Plug + Receptacle Cable Set
[2-pin JST SM Plug + Receptacle Cable Set](https://www.adafruit.com/product/2880)
These 2-wire cables are 16cm long and come as a set. One side has a 2-pin JST SM type connector plug on the end. The other side has a matching 2-pin JST SM type receptacle connector. They are good for whenever you have 2 wires you want to be able to plug and unplug....
In Stock
[Buy Now](https://www.adafruit.com/product/2880)
[Related Guides to the Product](https://learn.adafruit.com/products/2880/guides)
Note: For my project, I used a scavenged speaker that I had in my spare parts box, but the speaker listed above will work just fine!
You'll also need a pumpkin to carve, and I highly recommend choosing a plastic or foam pumpkin for this project. That way, you can enjoy your Jack-o-Theremin for many Halloweens to come! If you do build this into a real pumpkin, you'll need to cover all the electronics with plastic wrap or seal them in a plastic bag inside the pumpkin.
- [Next Page](https://learn.adafruit.com/jack-o-theremin/carve-the-pumpkin.md)
## Guide Products
### Circuit Playground Express
[Circuit Playground Express](https://www.adafruit.com/product/3333)
**Circuit Playground Express** is the next step towards a perfect introduction to electronics and programming. We've taken the original Circuit Playground Classic and made it even better! Not only did we pack even more sensors in, we also made it even easier to...
Out of Stock
[Buy Now](https://www.adafruit.com/product/3333)
[Related Guides to the Product](https://learn.adafruit.com/products/3333/guides)
### HC-SR04 Ultrasonic Sonar Distance Sensor + 2 x 10K resistors
[HC-SR04 Ultrasonic Sonar Distance Sensor + 2 x 10K resistors](https://www.adafruit.com/product/3942)
If you're like me, you've dreamed of being a dolphin - smoothly gliding through the water. Using your echo-location abilities to detect tasty fish treats. Until genetic modifications catches up with our desires, we'll just have to make do with these handy **HC-SR04 Ultrasonic...**
In Stock
[Buy Now](https://www.adafruit.com/product/3942)
[Related Guides to the Product](https://learn.adafruit.com/products/3942/guides)
### 3 x AAA Battery Holder with On/Off Switch and 2-Pin JST
[3 x AAA Battery Holder with On/Off Switch and 2-Pin JST](https://www.adafruit.com/product/727)
This battery holder connects 3 AAA batteries together in series for powering all kinds of projects. We spec'd these out because the box is slim, and 3 AAA's add up to about 3.3-4.5V, a very similar range to Lithium Ion/polymer (Li-Ion) batteries and have an on-off switch. That makes...
In Stock
[Buy Now](https://www.adafruit.com/product/727)
[Related Guides to the Product](https://learn.adafruit.com/products/727/guides)
### Mini Metal Speaker w/ Wires - 8 ohm 0.5W
[Mini Metal Speaker w/ Wires - 8 ohm 0.5W](https://www.adafruit.com/product/1890)
Listen up! This tiny 1" diameter speaker cone is the perfect addition to any small audio project where you need an 8 Ω impedance and will be using 0.5W or less of power. We particularly like this cone as it's very simple and its metal body is extremely lightweight.
Out of Stock
[Buy Now](https://www.adafruit.com/product/1890)
[Related Guides to the Product](https://learn.adafruit.com/products/1890/guides)
### 2-pin JST SM Plug + Receptacle Cable Set
[2-pin JST SM Plug + Receptacle Cable Set](https://www.adafruit.com/product/2880)
These 2-wire cables are 16cm long and come as a set. One side has a 2-pin JST SM type connector plug on the end. The other side has a matching 2-pin JST SM type receptacle connector. They are good for whenever you have 2 wires you want to be able to plug and unplug....
In Stock
[Buy Now](https://www.adafruit.com/product/2880)
[Related Guides to the Product](https://learn.adafruit.com/products/2880/guides)
## Related Guides
- [Adafruit Circuit Playground Express](https://learn.adafruit.com/adafruit-circuit-playground-express.md)
- [Ultrasonic Sonar Distance Sensors](https://learn.adafruit.com/ultrasonic-sonar-distance-sensors.md)
- [Magical Cardboard Craft Obsidian Sword](https://learn.adafruit.com/cardboard-obsidian-sword.md)
- [Personal UV HotSpot Parasol](https://learn.adafruit.com/personal-blacklight-uv-parasol.md)
- [NYE Circuit Playground Drop](https://learn.adafruit.com/nye-circuit-playground-drop.md)
- [Crickit Powered Dancin' Snowman!](https://learn.adafruit.com/crickit-powered-dancin-snowman.md)
- [Zombie Tag Game with Circuit Playground Express](https://learn.adafruit.com/circuit-playground-express-ir-zombie-game.md)
- [Circuit Playground Express Laser Tag](https://learn.adafruit.com/circuit-playground-express-laser-tag.md)
- [Glowing Neopixel Resin River Table](https://learn.adafruit.com/glowing-neopixel-resin-river-table.md)
- [Sparkle Skirt Playground](https://learn.adafruit.com/sparkle-skirt-playground.md)
- [What is Web MIDI & BLE MIDI?](https://learn.adafruit.com/web-ble-midi.md)
- [Icicle Crown with Pebble Pixels & WLED](https://learn.adafruit.com/icicle-crown-with-pebble-pixels-wled.md)
- [Cartoon Network MakeCode: Garnet's Palm Gems from Steven Universe](https://learn.adafruit.com/cartoon-network-makecode-garnet-s-palm-gems-from-steven-universe.md)
- [3D Printed Heel Clips](https://learn.adafruit.com/3d-printed-heel-clips.md)
- [MIDI Stomping Pads](https://learn.adafruit.com/midi-stomping-pads.md)
- [Light-Up Costumes in Harsh Environments](https://learn.adafruit.com/light-up-costumes-in-harsh-environments.md)
- [Wind Blowing Emoji Prop](https://learn.adafruit.com/wind-face-emoji.md)