# Bluetooth LE MIDI Controller ## Overview https://youtu.be/X1cI5xkjVC8 ![](https://cdn-learn.adafruit.com/assets/assets/000/039/159/medium800/3d_printing_hero-2.jpg?1486845912) ## A _Different_ Looking MIDI Controller In this guide, I'll show you how I built this strange looking MIDI controller. It doesn't look like your typical drumpad or keyboard, but it does have similar functionality just like any standard MIDI controller. It features six capacitive touch pads that trigger MIDI notes. Tap one of the pads, and it plays a note. It also features a step sequencer so you can record and playback a pattern. The 16 NeoPixel ring displays a glowing dot for each step which also follows the beat of a given tempo. It can also change settings, such as pitch, tempo, shuffle, length, velocity and even MIDI channel. ## BLE MIDI Drum Machine This project is based off of [Todd Treece's Capacitive Touch Drum Machine](../../../../capacitive-touch-drum-machine/). Todd's project uses an Arduino, MPR121 touch capacitive sensor and a strip of 16 NeoPixel LEDs to make a simple drum machine that you can use to control MIDI devices and virtual instruments. This project is built on top of that sketch and adds BLE connectivity. The future is here! ![](https://cdn-learn.adafruit.com/assets/assets/000/039/288/medium800/3d_printing_hero-1.jpg?1487038809) ## How Does It Work? The Feather 32u4 Bluefruit LE features the NRF51 chipset which supports Bluetooth low-energy. This means it can act like a HID keyboard, or in our case, send and receive MIDI notes over BLE. The MPR121 capacitive touch sensor features touch detection, so we can connect conductive materials to it. The Feather listens for any touches from the capacitive touch sensor and sends MIDI notes whenever a pin is pulled low or high.  ## Capacitive Touch Pads 3D Printed or CNC Milled? If you want to build this project, you have the option of 3D printing the capacitive touch pads using conductive PLA or CNC mill them out of conductive material like 6061 aluminum. The choice is yours! I tried both, and I really like the look and feel of aluminum capative touch pads. ![](https://cdn-learn.adafruit.com/assets/assets/000/039/160/medium800/3d_printing_hero-3.jpg?1486845940) ## DIY: Make It Your Own If you don't like the look of this project, but you still like the idea of building your own MIDI controller, you can re-use the code, components and circuit diagram to base your own MIDI controller from. Instead of using a NeoPixel ring, go for a strip. Or fabricate your own.  Don't like the shape or material of the pads? Make your own! Use copper foil tape, bare conductive paint or any electrically conductive material (how about fruits?). ## Prerequisite Guides If you want to build this project, I suggest you walk through the following guides below to get a better understanding of the components and libraries. - [Adafruit Feather 32u4 Bluefruit LE](../../../adafruit-feather-32u4-bluefruit-le) - [MPR121 Capacitive Touch Sensor](../../../adafruit-mpr121-12-key-capacitive-touch-sensor-breakout-tutorial/downloads?view=all) - [Capacitive Touch Drum Machine](../../../capacitive-touch-drum-machine/user-interface) - [Adding Custom Boards to Arduino IDE](../../../../adding-custom-boards-to-the-arduino-v1-6-board-manager) ![](https://cdn-learn.adafruit.com/assets/assets/000/039/068/medium800/3d_printing_parts.jpg?1486760132) ## Parts I used the following parts to build this project.  - [Adafruit Feather 32u4 Bluefruit LE](https://www.adafruit.com/products/2829) - [16 x NeoPixel Ring](https://www.adafruit.com/products/1463) - [MPR121 Capacitive Touch Sensor](https://www.adafruit.com/products/1982) - [2500mAh Lipo Battery](https://www.adafruit.com/products/328) - [Slide Switch](https://www.adafruit.com/products/805) - [Flex Perma-Proto](https://www.adafruit.com/products/1518) ## Tools & Supplies You'll need the following tools and supplise to build this project. - [Soldering Iron & Solder](https://www.adafruit.com/products/180) - [Tweezers](https://www.adafruit.com/products/3096) - [Panavise Jr.](https://www.adafruit.com/products/151) - [Third Helping Hands](https://www.adafruit.com/products/291) - [Copper Foil Tape](https://www.adafruit.com/products/1128) - [Heat Shrink Pack](https://www.adafruit.com/products/1649) - [30AWG silicone cover wire](https://www.adafruit.com/products/2051) - [Wire Strippers](https://www.adafruit.com/products/527) - [Diagonal Flush Snips](https://www.adafruit.com/product/152) - [Conductive PLA](https://www.adafruit.com/products/2703) (for 3D printing touch pads) - 4x 4-40 3/8 (or M3 - .5) machine screws - [Next Page](https://learn.adafruit.com/bluetooth-le-midi-controller/circuit-diagram.md) ## Featured Products ### Adafruit Feather 32u4 Bluefruit LE [Adafruit Feather 32u4 Bluefruit LE](https://www.adafruit.com/product/2829) Feather is the new development board from Adafruit, and like its namesake it is thin, light, and lets you fly! We designed Feather to be a new standard for portable microcontroller cores. This is the  **Adafruit Feather 32u4 Bluefruit**  - our take on an... In Stock [Buy Now](https://www.adafruit.com/product/2829) [Related Guides to the Product](https://learn.adafruit.com/products/2829/guides) ### NeoPixel Ring - 16 x 5050 RGB LED with Integrated Drivers [NeoPixel Ring - 16 x 5050 RGB LED with Integrated Drivers](https://www.adafruit.com/product/1463) Round and round and round they go! 16 ultra bright smart LED NeoPixels are arranged in a circle with 1.75" (44.5mm) outer diameter. The rings are 'chainable' - connect the output pin of one to the input pin of another. Use only one microcontroller pin to control as many as you can... In Stock [Buy Now](https://www.adafruit.com/product/1463) [Related Guides to the Product](https://learn.adafruit.com/products/1463/guides) ### Adafruit 12-Key Capacitive Touch Sensor Breakout - MPR121 [Adafruit 12-Key Capacitive Touch Sensor Breakout - MPR121](https://www.adafruit.com/product/1982) Add lots of touch sensors to your next microcontroller project with this easy-to-use 12-channel capacitive touch sensor breakout board, starring the MPR121. This chip can handle up to 12 individual touchpads. The MPR121 has support for only I2C, which can be implemented with nearly... In Stock [Buy Now](https://www.adafruit.com/product/1982) [Related Guides to the Product](https://learn.adafruit.com/products/1982/guides) ### Breadboard-friendly SPDT Slide Switch [Breadboard-friendly SPDT Slide Switch](https://www.adafruit.com/product/805) These nice switches are perfect for use with breadboard and perfboard projects. They have 0.1" spacing and snap in nicely into a solderless breadboard. They're easy to switch no matter what size fingers you have, but not so easy that they'll get flipped by accident. Work great as... In Stock [Buy Now](https://www.adafruit.com/product/805) [Related Guides to the Product](https://learn.adafruit.com/products/805/guides) ### Lithium Ion Polymer Battery - 3.7v 2500mAh [Lithium Ion Polymer Battery - 3.7v 2500mAh](https://www.adafruit.com/product/328) Lithium-ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light, and powerful. The output ranges from 4.2V when completely charged to 3.7V. This battery has a capacity of **2500mAh** for a total of about 10 Wh. If you need a smaller battery, In Stock [Buy Now](https://www.adafruit.com/product/328) [Related Guides to the Product](https://learn.adafruit.com/products/328/guides) ### Silicone Cover Stranded-Core Wire - 30AWG in Various Colors [Silicone Cover Stranded-Core Wire - 30AWG in Various Colors](https://www.adafruit.com/product/2051) Silicone-sheathing wire is super-flexible and soft, and its also strong! Able to handle up to 200°C and up to 600V, it will do when PVC covered wire wimps out. We like this wire for being extremely supple and flexible, so it is great for wearables or projects where the wire-harness has to... Out of Stock [Buy Now](https://www.adafruit.com/product/2051) [Related Guides to the Product](https://learn.adafruit.com/products/2051/guides) ### Adafruit Flex Perma-Proto - Half-sized Breadboard Flex-PCB [Adafruit Flex Perma-Proto - Half-sized Breadboard Flex-PCB](https://www.adafruit.com/product/1518) Make your next project super-flexy with a prototyping board that can twist and bend. We took our lovely classic perma-proto design and had it made from incredibly thin polyamide film. It's extremely bendable, and you can cut it easily with scissors. It has a bend radius of 1cm or better... In Stock [Buy Now](https://www.adafruit.com/product/1518) [Related Guides to the Product](https://learn.adafruit.com/products/1518/guides) ### Copper Foil Tape with Conductive Adhesive - 6mm x 15 meter roll [Copper Foil Tape with Conductive Adhesive - 6mm x 15 meter roll](https://www.adafruit.com/product/1128) Copper tape can be an interesting addition to your toolbox. The tape itself is made of thin pure copper so its extremely flexible and can take on nearly any shape. You can easily solder to it, and the tape itself can carry current just like a wire. On the back is an electrically conductive... In Stock [Buy Now](https://www.adafruit.com/product/1128) [Related Guides to the Product](https://learn.adafruit.com/products/1128/guides) ## Related Guides - [Glowing LED Chair](https://learn.adafruit.com/glowing-led-chair.md) - [Custom Bluetooth Cherry MX Gamepad](https://learn.adafruit.com/custom-wireless-bluetooth-cherry-mx-gamepad.md) - [Green Goblin Pumpkin CPB Ornament](https://learn.adafruit.com/green-goblin-pumpkin-cpb-ornament.md) - [Raspberry Pi Zero NPR One Radio](https://learn.adafruit.com/raspberry-pi-zero-npr-one-radio.md) - [Watchmen's Sister Night NeoPixel Goggles](https://learn.adafruit.com/watchmen-sister-night-circuitpython-neopixel-goggles.md) - [CircuitPython Media Dial](https://learn.adafruit.com/media-dial.md) - [Mindfulness Clock OF DOOM](https://learn.adafruit.com/mindfulness-clock-of-doom.md) - [Introducing Adafruit Feather](https://learn.adafruit.com/adafruit-feather.md) - [Halo Energy Sword](https://learn.adafruit.com/halo-energy-sword.md) - [Using NeoPixels with Netduino Plus 2](https://learn.adafruit.com/using-neopixels-with-netduino.md) - [3D Printed Flora Band](https://learn.adafruit.com/3d-printed-flora-band.md) - [Adafruit Capacitive Touch Sensor Breakouts](https://learn.adafruit.com/adafruit-capacitive-touch-sensor-breakouts.md) - [Superhero Power Plant](https://learn.adafruit.com/superhero-power-plant.md) - [Capacitive Touch Drum Machine](https://learn.adafruit.com/capacitive-touch-drum-machine.md) - [Prop-Maker Keyblade](https://learn.adafruit.com/propmaker-keyblade.md)