Text Editor

Adafruit recommends using the Mu editor for editing your CircuitPython code. You can get more info in this guide.

Alternatively, you can use any text editor that saves simple text files.

Download the Project Bundle

Your project will use a specific set of CircuitPython libraries and the code.py file. To get everything you need, click on the Download Project Bundle link below, and uncompress the .zip file.

Drag the contents of the uncompressed bundle directory onto your Feather board's CIRCUITPY drive, replacing any existing files or directories with the same names, and adding any new ones that are necessary.

# SPDX-FileCopyrightText: 2021 john park for Adafruit Industries
# SPDX-License-Identifier: MIT
# NeoController: NeoSlider(x4) + NeoKey MIDI input device

import board
import busio
from adafruit_simplemath import map_range
import usb_midi
import adafruit_midi
from adafruit_midi.control_change import ControlChange
from adafruit_midi.note_on import NoteOn
from adafruit_midi.note_off import NoteOff
from adafruit_seesaw.seesaw import Seesaw
from adafruit_seesaw import neopixel
from adafruit_seesaw.analoginput import AnalogInput
from adafruit_neokey.neokey1x4 import NeoKey1x4

i2c = busio.I2C(board.SCL, board.SDA)  # for QT Py RP2040, use SCL1/SDA1

# --- NeoSlider object setup
addresses = (0x30, 0x31, 0x32, 0x33)  # cut jumpers to proper addreses (none, A0, A1, A0+A1)
neosliders = []  # list to hold neoslider objects
for address in addresses:  # create each neoslider w proper address
    temp_neosliders = Seesaw(i2c, address)
    neosliders.append(temp_neosliders)  # append to the list

# --- NeoSlider analog read setup
analogin_pin = 18  # slider is on this analog pin
analog_pins = (0, 1)
analog_inputs = []
for n in range(len(neosliders)):
    temp_analog_in = AnalogInput(neosliders[n], analogin_pin)
    analog_inputs.append(temp_analog_in)

# --- Slider NeoPixels Setup
PIX_PIN = 14
PIX_NUM = 4
pixels = []
for p in range(len(neosliders)):
    temp_pix = neopixel.NeoPixel(neosliders[p], PIX_PIN, PIX_NUM)
    pixels.append(temp_pix)
    pixels[p].brightness = 1.0
    pixels[p].fill((20, 20, 0))
    pixels[p].show()

# --- NeoKey 1x4 Setup --- #
neokey = NeoKey1x4(i2c, addr=0x38)
amber = 0x300800
blue = 0x002040
red = 0x900000
neokey.pixels.fill(amber)

keys = [  # neokey (adjust if multiple sets), key number, keypress color, MIDI note
    (neokey, 0, blue, 40),
    (neokey, 1, red, 42),
    (neokey, 2, blue, 43),
    (neokey, 3, red, 46),
]

#  states for key presses
key_states = [False, False, False, False]


# --- MIDI setup
midi = adafruit_midi.MIDI(
                        midi_in=usb_midi.ports[0],
                        in_channel=(0),
                        midi_out=usb_midi.ports[1],
                        out_channel=0
)
cc_numbers = [48, 49, 50, 51]  # pick the CC number for each slider to send over

last_sliders = [0] * len(neosliders)  # list to hold state variables

while True:
    # check NeoKeys
    for k in range(len(keys)):
        neokey, key_number, color, midi_note = keys[k]
        if neokey[key_number] and not key_states[key_number]:
            midi.send(NoteOn(midi_note, 127))
            key_states[key_number] = True
            neokey.pixels[key_number] = color
        if not neokey[key_number] and key_states[key_number]:
            midi.send(NoteOff(midi_note, 0))
            neokey.pixels[key_number] = amber
            key_states[key_number] = False

    # check sliders
    for i in range(len(neosliders)):
        slider = analog_inputs[i].value
        if abs(slider - last_sliders[i]) > 1:
            cc_val = int(map_range(slider, 0, 1023, 0, 127))
            midi.send(ControlChange(cc_numbers[i], cc_val))
            color_val = int(map_range(slider, 0, 1023, 5, 255))
            pixels[i].fill((color_val, color_val, 0))
            last_sliders[i] = slider

Customize Settings

The code allows you to customize the MIDI note values and CC numbers. To change the notes the keyswitches send, change the fourth value of the items in this list:

keys = [  # neokey (adjust if multiple sets), key number, keypress color, MIDI note
    (neokey, 0, blue, 40),
    (neokey, 1, red, 42),
    (neokey, 2, blue, 43),
    (neokey, 3, red, 46),
]

In order to send the 0-127 values over different CC numbers when you move the NeoSliders, adjust this list:

cc_numbers = [48, 49, 50, 51]  # pick the CC number for each slider to send over

This guide was first published on Dec 19, 2021. It was last updated on Dec 19, 2021.

This page (Code the Neocontroller) was last updated on Jan 19, 2022.

Text editor powered by tinymce.