Circuit Python Ble Midi On Windows

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Made by usini / Art / Music

About the project

Wireless Midi is pretty cool but it is a bit tricky on Windows, here how to do it

Project info

Items used in this project

Hardware components

MPR121 Pad MPR121 Pad x 1
Adafruit NRF Sense Adafruit NRF Sense x 1

Software apps and online services

LoopMidi LoopMidi Create Virtual Midi Controller
MidiBerry MidiBerry This application connect a BLE Midi controller to a Virtual Midi controller


Make a BLE Midi device using an nrf82540 board

We are going to use an Adafruit NRF Sense but any NRF82540 board will do.

You will need theses libraries:

  • adafruit_ble
  • adafruit_ble_midi.mpy
  • adafruit_midi

You can get the libraries here :

Here is a code to test if BLE Midi works correctly, it will play a note, wait 1 seconds and stop it.

Save it on your circuit python drive as

import time

# Midi
import adafruit_midi
from adafruit_midi.note_off import NoteOff
from adafruit_midi.note_on import NoteOn

# BLE Midi
import adafruit_ble
from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
import adafruit_ble_midi

# Setup BLE Midi
midi_service = adafruit_ble_midi.MIDIService()
advertisement = ProvideServicesAdvertisement(midi_service)
midi = adafruit_midi.MIDI(midi_out=midi_service, out_channel=0)
ble = adafruit_ble.BLERadio()

# Make BLE Device visible
print("Waiting for BLE MIDI connection")
while True:
# If not connected, don't execute the rest of the code
while not ble.connected:

while ble.connected:
midi.send(NoteOn(70, 127))
print("NOTE ON")
midi.send(NoteOff(0, 0))
print("NOTE OFF")

# If disconnect, wait for reconnection
print("Advertising BLE")

Setup Windows for BLE Midi

As said on this Adafruit tutorial, BLE Midi support on Windows are unfortunately not well supported.

I didn't manage to make it works without using additionnal software.

However you can add BLE Midi support using MidiBerry and LoopMidi

Connect your BLE device

First you need to connect your board to your computer, it should appear as CIRCUITPYd06c


MidiBerry connect a Midi / BLE Midi device to another Midi device.

We didn't make an virtual midi device yet but we can test if everything works correctly using Microsoft GS Wavetable

In Input use CIRCUITPyd06c (not CircuitPython usb_midi_ports).
In Output
use Microsoft GS Wavetable

You need to restart midiberry each times you change your python code

It should play a piano note, each second.


LoopMidi create a virtual midi device, we can route our BLE device to use it with any music software.

Create a virtual device (I named it BleMidi but by default it is called loopMIDI port)

Go back to MidiBerry and connect your circuit python board to your virtual midi device.

Test your device with Helm

You should now be able to use your board on any music software, for example, Helm, a free synthetizer software.It detect automatically your midi device so it should be easy to try it.

Going Further

Now you can start building your own wireless midi devices.

I'm using an MPR121 pads, they only require 4 cables (SDA/SCL/GND/VCC) as it uses i²c.

Here is my code I used on the video, i'm also using the APDS9960 Proximity Sensor to control the pitch.




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