modwheel.py

gistfile1.txt

import time
import board
import busio
from simpleio import map_range
from analogio import AnalogIn
from digitalio import DigitalInOut, Direction
import usb_midi
import adafruit_midi  # MIDI protocol encoder/decoder library
from adafruit_midi.control_change import ControlChange
from adafruit_midi.note_on          import NoteOn


USB_MIDI_channel = 1 

usb_midi = adafruit_midi.MIDI(
    midi_out=usb_midi.ports[1], out_channel=USB_MIDI_channel - 1
)

knob = AnalogIn(board.A2)

cc_number = 1

cc_range = (0, 127)

cc_value = (0,0)

last_cc_value = (0,0)

def range_index(ctl, ctrl_max, old_idx, offset):
    if (ctl + offset > 65535) or (ctl + offset < 0):
        offset = 0
    idx = int(map_range((ctl + offset) & 0xFF00, 1200, 65500, 0, ctrl_max))
    if idx != old_idx:  # if index changed, adjust hysteresis offset
        # offset is 25% of the control slice (65536/ctrl_max)
        offset = int(
            0.25 * sign(idx - old_idx) * (65535 / ctrl_max)
        )  # edit 0.25 to adjust slices
    return idx, offset


def sign(x):  # determine the sign of x
    if x >= 0:
        return 1
    else:
        return -1

counter = 0

while True:

    cc_value = range_index(
        knob.value,
        (cc_range[1] - cc_range[0] + 1),
        cc_value[0],
        cc_value[1],
    )
    if cc_value != last_cc_value:  # only send if it changed
        # Form a MIDI CC message and send it:
        usb_midi.send(ControlChange(cc_number, cc_value[0] + cc_range[0]))
        print("sending change")
        print(cc_value)
        print(last_cc_value)
        print(knob.value)
        last_cc_value = cc_value

    time.sleep(0.01)