MIDI CC knob controller example for Raspberry Pi Pico

code.py

import time
import board

import usb_midi
import adafruit_midi

from analogio import AnalogIn
from adafruit_midi.control_change import ControlChange

# MIDI CC knob controller example for Raspberry Pi Pico

# Prerequisites
#
# Requires Adafruit CircuitPython: https://learn.adafruit.com/getting-started-with-raspberry-pi-pico-circuitpython
# Also requires the following CircuitPython libs: adafruit_midi (drop it into the lib folder)
#
# Save this code in code.py on your Raspberry Pi Pico CIRCUITPY drive


# Read analog pin voltage
def get_voltage(pin):
    return (pin.value * 3.3) / 65536


# The potentiometers' middle pins are connected to analog pins 27 and 28, the
# outer pins to GND and 3v3.
knob_1 = AnalogIn(board.GP27)
knob_2 = AnalogIn(board.GP28)

# Set up MIDI
midi = adafruit_midi.MIDI(midi_out=usb_midi.ports[1], out_channel=0)

# Use these variables to only update when the value changes
last_knob_1_val = 0
last_knob_2_val = 0

while True:
    # Read voltages and convert to 0-127 (MIDI note range)
    knob_1_val = min(max(int(get_voltage(knob_1) / 3.3 * 128), 0), 127)
    knob_2_val = min(max(int(get_voltage(knob_2) / 3.3 * 128), 0), 127)

    # If value has changed since last value, send MIDI CC message
    if knob_1_val != last_knob_1_val:
        midi.send(ControlChange(1, knob_1_val))
        last_knob_1_val = knob_1_val
    if knob_2_val != last_knob_2_val:
        midi.send(ControlChange(2, knob_2_val))
        last_knob_2_val = knob_2_val

Just forking for reference later