The Accessible Music Project


The following Micro Controllers, Sound Generators, Amplifiers and Sensors are used in the projects and devices found on this web site.

Micro Controllers

Device Description
Arduino Uno

Arduino Uno Micro Controller

This is the main electronic device (with it's variants) that is used as a standalone MIDI controller for the majority of the projects displayed on this web site.

An Arduino is an open-source electronics platform based on easy-to-use hardware and software. It's intended for anyone making interactive projects. Arduino senses the environment by receiving inputs from many sensors, and affects its surroundings by controlling lights, motors, and other actuators

A "Genuine" device cost around £20, but an open source clone can be had for around £5.00 if you are in the habit of making blue smoke with them.

Bare Conductive Touch Board

Bare Conductive Touch Board

This combines a version of an Arduino with a 12 electrode input capacitive sensor and an Audio CODEC than can play MIDI, MP3, WAV and Ogg Vorbis files. Therefore it is very versatile device though at £60 plus pound fairly expensive.

N.B. "Shields" are small circuit boards that piggy-back onto the top of Arduino Uno and Mega boards and their equivalent clones. They add extra functionality such as playing audio files. Other shields can also provide onboard data logging, GPS, environmental sensing and much more.

Sound Creation: Audio Shields (MIDI/ WAV/MP3 and Sound Effect Circuit Boards



MIDI Music Sheild

Music Instrument Shield (Sparkfun)

The SparkFun Musical Instrument Shield is an easy way to add great sounding MIDI sound to your next Arduino project. This board is built around the VS1053 MP3 and MIDI codec IC, wired in MIDI mode. Simply connect a speaker/stereo/pair of headphones to the 1/8" stereo jack on the shied and pass the proper serial commands to the IC and you'll be playing music in no time! The VS1053 contains two large tone banks including various piano, woodwinds, brass, synth, SFX and percussion sounds. The shield is also capable of playing several tones simultaneously (maximum polyphony of up to 31 sounds). They cost around £24.00


Adafruit Audio FX Mini Sound Board WAV/OGG Trigger 16MB Flash

The Audio FX Mini sound board is a simple to use, low cost audio effects trigger that does not require any programming. It does not need an Arduino+Shield


  • No Arduino or other micro controller required. It is completely stand-alone, just needs a 3 to 5.5VDC battery
  • Built in storage - there's 16MB of storage on the board itself. Good for ~15 minutes of compressed stereo, and maybe a couple minutes of uncompressed stereo. Double that if you go with mono instead of stereo.
  • Compressed or Uncompressed audio - Go with compressed Ogg Vorbis files for longer audio files, or uncompressed WAV files
  • High Quality Sound - Up to 44.1KHz 16 bit stereo? The decoding hardware can handle any bit/sample rate and mono or stereo
  • Triggers - Connect up to 11 buttons or switches, each one can trigger audio files.
  • Stereo line out - Headphones, powered speakers.

For reference, trigger options are as follows:-

  1. Basic Trigger - name the file Tnn.WAV or Tnn.OGG to have the audio file play when the matching trigger pin nn is connected to ground momentarily
  2. Hold Looping Trigger - name the file TnnHOLDL.WAV or .OGG to have the audio play only when the trigger pin is held low, it will loop until the pin is released
  3. Latching Loop Trigger - name the file TnnLATCH.WAV or .OGG to have the audio start playing when the button is pressed momentarily, and repeats until the button is pressed again
  4. Play Next Trigger - have up to 10 files play one after the other by naming them TnnNEXT0.WAV thru TnnNEXT9.OGG. Will start with #0 and each one on every momentary button press until it gets through all of them, then go back to #0
  5. Play Random Trigger - just like the Play Next trigger, but will play up to 10 files in random order (TnnRAND0.OGG thru TnnRAND9.OGG) every time the button is pressed momentarily


SparkFun MP3 Player

MP3 Player Arduino Shield

The SparkFun MP3 Player Shield is anMP3 decoder with the capabilities of storing music files onto a run-of-the-mill microSD card, giving the ability to add music or sound effects to any project. With this board you can pull MP3 files from an microSD card and play them using only one shield, effectively turning any Arduino into a fully functional stand-alone MP3 player! The MP3 Shield utilizes the VS1053B MP3 audio decoder IC to decode audio files.

The VS1053 is also capable of decoding Ogg Vorbis /MP3/ AAC/ WMA/ MIDI audio and encoding IMA ADPCM and user-loadable Ogg Vorbis.


  • 3.5mm audio out jack
  • 0.1" spaced header for speaker out
  • microSD card slot
Adafruit Music Sheild

Adafruit Music shield

It will play a range of music formats. The files are placed on a micro SD card. It has the added advantage of a built in 3W class D stereo amplifier.



These amplify the low powered "line" signal from shields and circuit boards.
Device Description
Mini Amp

Audio Amplifier

Generic Class D Stereo Amplifier. It runs happily on 9v and is surprisingly loud. Used in about 50% of my projects. They cost around £3.00.

This one has the advantage of small size, volume control and can run off 6-15v. It is worth checking that the voltage range fits in with the other components used (I have been caught out this way a couple of times).

Class D Stereo amp

Class D stereo Amplifier, 3 Watt. N.B. Class D means it amplifiers digitally, sending pulses to a speaker. The speaker acts a s low pass filter converting the signal to analogue.

THe digital nature of the's amps can make "hissy". In addition, quick changes in sound level can cause glitches which can disrupt the Arduino if they share the same battery supply.



Device Description
Ultrasonic range finder Ultrasonic Range Finders
These can detect how far away and object is (from a few centimetres up to 3 or 4 metres). Detecting distances of (say) 10, 20, 30, centimetres can form the basis of either an air guitar or an air drum. See the Air-Drum-Flute-Guitar.These devices can be had for around £1.00. More expensive versions (£24+) have additional components to compensate for changes in air temperature and humidity.
IR Range Finder

Infra Red (IR) range finder.

These detect infrared light reflected back from another surface and give an estimate of distance, typically within 10cm to a metre.


Sparkfun "Nine Degrees of Fredom", it has a 3-Axis Gyroscope with four selectable ranges, 3-Axis Accelerometer, again with four selectable ranges, and 3-axis magnetometer.

SparkFun 9DoF IMU Breakout - ICM-20948 (Qwiic)


Infra Red (IR) Receiver

Infra Red (IR) receiver

These can be used in conjunction with an inexpensive remote control. This in turn can reduce the number of control buttons in a base unit.

IR Remote Small IR remote control
Rotary Switch - resitive ladder

Rotary switch: Used for" Resistive Ladder" selection.

This is wired up to give outputs or 0v, 1v, 2v, 3v, 4v, 5v. Connecting to the analogue input of a micro controller such as Arduino UNO allows the selection of different functions e.g. selecting an instrument, a key signature, an octave, a time signature or beats per minute.

Floor Actuators Alarm pressure pads can be used to create foot operated switches.