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Uploading MIDI guitar code
Code for MX MIDI Guitar learn guide
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‎MX MIDI Guitar/code.py

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import time
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import board
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import simpleio
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import busio
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import adafruit_lis3dh
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import digitalio
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from digitalio import DigitalInOut, Direction, Pull
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from analogio import AnalogIn
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import usb_midi
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import adafruit_midi
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from adafruit_midi.note_on import NoteOn
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from adafruit_midi.note_off import NoteOff
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from adafruit_midi.control_change import ControlChange
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from adafruit_midi.pitch_bend import PitchBend
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# imports MIDI
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midi = adafruit_midi.MIDI(midi_out=usb_midi.ports[1], out_channel=0)
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# setup for LIS3DH accelerometer
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i2c = busio.I2C(board.SCL, board.SDA)
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lis3dh = adafruit_lis3dh.LIS3DH_I2C(i2c)
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lis3dh.range = adafruit_lis3dh.RANGE_2_G
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# setup for 3 potentiometers
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pitchbend_pot = AnalogIn(board.A1)
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mod_pot = AnalogIn(board.A2)
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velocity_pot = AnalogIn(board.A3)
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# setup for two switches that will switch modes
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mod_select = DigitalInOut(board.D52)
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mod_select.direction = Direction.INPUT
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mod_select.pull = Pull.UP
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strum_select = DigitalInOut(board.D53)
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strum_select.direction = Direction.INPUT
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strum_select.pull = Pull.UP
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# setup for strummer switches
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strumUP = DigitalInOut(board.D22)
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strumUP.direction = Direction.INPUT
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strumUP.pull = Pull.UP
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strumDOWN = DigitalInOut(board.D23)
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strumDOWN.direction = Direction.INPUT
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strumDOWN.pull = Pull.UP
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# setup for cherry mx switches on neck
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note_pins = [board.D14, board.D2, board.D3, board.D4, board.D5,
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board.D6, board.D7, board.D8, board.D9, board.D10, board.D11, board.D12]
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note_buttons = []
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for pin in note_pins:
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note_pin = digitalio.DigitalInOut(pin)
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note_pin.direction = digitalio.Direction.INPUT
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note_pin.pull = digitalio.Pull.UP
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note_buttons.append(note_pin)
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# setup for rotary switch
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oct_sel_pins = [board.D24, board.D25, board.D26, board.D27, board.D28, board.D29,
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board.D30, board.D31]
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octave_selector = []
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for pin in oct_sel_pins:
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sel_pin = digitalio.DigitalInOut(pin)
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sel_pin.direction = digitalio.Direction.INPUT
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sel_pin.pull = digitalio.Pull.UP
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octave_selector.append(sel_pin)
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# cherry mx switch states
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note_e_pressed = None
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note_f_pressed = None
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note_fsharp_pressed = None
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note_g_pressed = None
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note_gsharp_pressed = None
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note_a_pressed = None
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note_asharp_pressed = None
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note_b_pressed = None
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note_c_pressed = None
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note_csharp_pressed = None
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note_d_pressed = None
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note_dsharp_pressed = None
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# state machines
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strummed = None
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pick = None
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up_pick = None
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down_pick = None
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# states for analog inputs
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pitchbend_val2 = 0
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mod_val2 = 0
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velocity_val2 = 0
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acc_pos_val2 = 0
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acc_neg_val2 = 0
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# array for cherry mx switch states
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note_states = [note_e_pressed, note_f_pressed, note_fsharp_pressed, note_g_pressed,
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note_gsharp_pressed, note_a_pressed, note_asharp_pressed, note_b_pressed,
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note_c_pressed, note_csharp_pressed, note_d_pressed, note_dsharp_pressed]
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# array of MIDI note numbers
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note_numbers = [21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
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41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,
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61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80,
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81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100,
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101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116,
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117, 118, 119, 120, 121, 120, 123, 124, 125, 126, 127]
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# list of note name variables that are assigned to the note_numbers array
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# this allows you to use the note names rather than numbers when assigning
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# them to the cherry mx switches
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(A0, Bb0, B0, C1, Db1, D1, Eb1, E1, F1, Gb1, G1, Ab1,
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A1, Bb1, B1, C2, Db2, D2, Eb2, E2, F2, Gb2, G2, Ab2,
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A2, Bb2, B2, C3, Db3, D3, Eb3, E3, F3, Gb3, G3, Ab3,
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A3, Bb3, B3, C4, Db4, D4, Eb4, E4, F4, Gb4, G4, Ab4,
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A4, Bb4, B4, C5, Db5, D5, Eb5, E5, F5, Gb5, G5, Ab5,
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A5, Bb5, B5, C6, Db6, D6, Eb6, E6, F6, Gb6, G6, Ab6,
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A6, Bb6, B6, C7, Db7, D7, Eb7, E7, F7, Gb7, G7, Ab7,
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A7, Bb7, B7, C8, Db8, D8, Eb8, E8, F8, Gb8, G8, Ab8,
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A8, Bb8, B8, C9, Db9, D9, Eb9, E9, F9, Gb9, G9) = note_numbers
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# arrays for note inputs that are tied to the rotary switch
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octave_8_cc = [E8, F8, Gb8, G8, Ab8, A8, Bb8, B8, C9, Db9, D9, Eb9]
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octave_7_cc = [E7, F7, Gb7, G7, Ab7, A7, Bb7, B7, C8, Db8, D8, Eb8]
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octave_6_cc = [E6, F6, Gb6, G6, Ab6, A6, Bb6, B6, C7, Db7, D7, Eb7]
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octave_5_cc = [E5, F5, Gb5, G5, Ab5, A5, Bb5, B5, C6, Db6, D6, Eb6]
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octave_4_cc = [E4, F4, Gb4, G4, Ab4, A4, Bb4, B4, C5, Db5, D5, Eb5]
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octave_3_cc = [E3, F3, Gb3, G3, Ab3, A3, Bb3, B3, C4, Db4, D4, Eb4]
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octave_2_cc = [E2, F2, Gb2, G2, Ab2, A2, Bb2, B2, C3, Db3, D3, Eb3]
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octave_1_cc = [E1, F1, Gb1, G1, Ab1, A1, Bb1, B1, C2, Db2, D2, Eb2]
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octave_select = [octave_1_cc, octave_2_cc, octave_3_cc, octave_4_cc,
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octave_5_cc, octave_6_cc, octave_7_cc, octave_8_cc]
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# function for reading analog inputs
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def val(voltage):
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return voltage.value
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# beginning script REPL printout
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print("MX MIDI Guitar")
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print("Default output MIDI channel:", midi.out_channel + 1)
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# loop
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while True:
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# values for LIS3DH
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x, y, z = [value / adafruit_lis3dh.STANDARD_GRAVITY for value in lis3dh.acceleration]
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# mapping analog values to MIDI value ranges
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# PitchBend MIDI has a range of 0 to 16383
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# all others used here are 0 to 127
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pitchbend_val1 = round(simpleio.map_range(val(pitchbend_pot), 0, 65535, 0, 16383))
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mod_val1 = round(simpleio.map_range(val(mod_pot), 0, 65535, 0, 127))
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velocity_val1 = round(simpleio.map_range(val(velocity_pot), 0, 65535, 0, 127))
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acc_pos_val1 = round(simpleio.map_range(x, 0, 0.650, 127, 0))
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acc_neg_val1 = round(simpleio.map_range(y, -0.925, 0, 127, 0))
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# checks if modulation switch is engaged
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if not mod_select.value:
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# if it is, then get modulation MIDI data from LIS3DH
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# positive and negative values for LIS3DH depending on
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# orientation of the guitar neck
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# when the guitar is held "normally" aka horizontal
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# then the modulation value is neutral aka 0
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# compares previous LIS3DH value to current value
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if abs(acc_pos_val1 - acc_pos_val2) < 50:
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# updates previous value to hold current value
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acc_pos_val2 = acc_pos_val1
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# MIDI data has to be sent as an integer
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# this converts the LIS3DH data into an int
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accelerator_pos = int(acc_pos_val2)
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# int is stored as a CC message
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accWheel_pos = ControlChange(1, accelerator_pos)
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# CC message is sent
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midi.send(accWheel_pos)
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# delay to settle MIDI data
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time.sleep(0.001)
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# same code but for negative values
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elif abs(acc_neg_val1 - acc_neg_val2) < 50:
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acc_neg_val2 = acc_neg_val1
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accelerator_neg = int(acc_neg_val2)
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accWheel_neg = ControlChange(1, accelerator_neg)
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midi.send(accWheel_neg)
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print(accelerator_neg)
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time.sleep(0.001)
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# if it isn't then get modulation MIDI data from pot
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else:
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# compares previous mod_pot value to current value
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if abs(mod_val1 - mod_val2) > 2:
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# updates previous value to hold current value
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mod_val2 = mod_val1
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# MIDI data has to be sent as an integer
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# this converts the pot data into an int
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modulation = int(mod_val2)
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# int is stored as a CC message
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modWheel = ControlChange(1, modulation)
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# CC message is sent
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midi.send(modWheel)
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# delay to settle MIDI data
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time.sleep(0.001)
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# reads analog input to send MIDI data for Velocity
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# compares previous velocity pot value to current value
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if abs(velocity_val1 - velocity_val2) > 2:
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# updates previous value to hold current value
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velocity_val2 = velocity_val1
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# MIDI data has to be sent as an integer
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# this converts the pot data into an int
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# velocity data is sent with NoteOn message
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# NoteOn is sent in the loop
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velocity = int(velocity_val2)
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# delay to settle MIDI data
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time.sleep(0.001)
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# reads analog input to send MIDI data for PitchBend
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# compares previous picthbend pot value to current value
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if abs(pitchbend_val1 - pitchbend_val2) > 75:
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# updates previous value to hold current value
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pitchbend_val2 = pitchbend_val1
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# MIDI data has to be sent as an integer
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# this converts the pot data into an int
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# int is stored as a PitchBend message
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a_pitch_bend = PitchBend(int(pitchbend_val2))
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# PitchBend message is sent
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midi.send(a_pitch_bend)
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# delay to settle MIDI data
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time.sleep(0.001)
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# checks position of the rotary switch
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# determines which notes are mapped to the cherry mx switches
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for s in octave_selector:
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if not s.value:
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o = octave_selector.index(s)
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octave = octave_select[o]
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# checks if strum select switch is engaged
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if not strum_select.value:
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# if it is, then:
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# setup states for both strummer switches
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if strumUP.value and up_pick is None:
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up_pick = "strummed"
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pick = time.monotonic()
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if strumDOWN.value and down_pick is None:
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down_pick = "strummed"
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pick = time.monotonic()
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# bug fix using time.monotonic(): if you hit the strummer, but don't hit a note
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# the state of the strummer switch is reset
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if (not pick) or ((time.monotonic() - pick) > 0.5 and
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(down_pick or up_pick == "strummed")):
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up_pick = None
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down_pick = None
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# if either strummer switch is hit
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if (not strumUP.value and up_pick == "strummed") or (not strumDOWN.value
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and down_pick == "strummed"):
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# indexes the cherry mx switch array
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for i in range(12):
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buttons = note_buttons[i]
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# if any of the mx cherry switches are pressed
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# and they weren't previously pressed (checking note_states[i])
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# where i is the matching index from the note_buttons array
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if not buttons.value and not note_states[i]:
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# send the NoteOn message that matches with the octave[i] array
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# along with the velocity value
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midi.send(NoteOn(octave[i], velocity))
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# note state is updated
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note_states[i] = True
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# updates strummer switch states
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up_pick = None
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down_pick = None
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# delay to settle MIDI data
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time.sleep(0.001)
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# the next if statement allows for you to strum notes multiple times without
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# having to release the note
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# if either strummer switch is hit
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if (not strumUP.value and up_pick == "strummed") or (not strumDOWN.value
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and down_pick == "strummed"):
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# indexes the cherry mx switch array
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for i in range(12):
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buttons = note_buttons[i]
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# if any of the cherry mx switches are pressed
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# and they *were* previously pressed (checking note_states[i])
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# where i is the matching index from the note_buttons array
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if not buttons.value and note_states[i]:
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# send the NoteOn message that matches with the octave[i] array
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# along with the velocity value
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midi.send(NoteOn(octave[i], velocity))
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# note state is updated
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note_states[i] = True
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# updates strummer switch states
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up_pick = None
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down_pick = None
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# sends a NoteOff message to prevent notes from
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# staying on forever aka preventing glitches
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midi.send(NoteOff(octave[i], velocity))
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# delay to settle MIDI data
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time.sleep(0.001)
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# the next for statement sends NoteOff when the cherry mx switches
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# are released
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# indexes the cherry mx switch array
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for i in range(12):
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buttons = note_buttons[i]
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# if any of the cherry mx switches are released
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# and they *were* previously pressed (checking note_states[i])
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# where i is the matching index from the note_buttons array
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if buttons.value and note_states[i]:
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# send the NoteOff message that matches with the octave[i] array
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# along with the velocity value
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midi.send(NoteOff(octave[i], velocity))
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# note state is updated
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note_states[i] = False
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# updates strummer switch states
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down_pick = None
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up_pick = None
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# delay to settle MIDI data
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time.sleep(0.001)
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# if strum select switch is not engaged
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else:
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# indexes the cherry mx switch array
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for i in range(12):
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buttons = note_buttons[i]
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# if any of the mx cherry switches are pressed
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# and they weren't previously pressed (checking note_states[i])
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# where i is the matching index from the note_buttons array
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if not buttons.value and not note_states[i]:
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# send the NoteOn message that matches with the octave[i] array
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# along with the velocity value
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midi.send(NoteOn(octave[i], velocity))
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# note state is updated
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note_states[i] = True
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# delay to settle MIDI data
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time.sleep(0.001)
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# if any of the cherry mx switches are released
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# and they *were* previously pressed (checking note_states[i])
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# where i is the matching index from the note_buttons array
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if (buttons.value and note_states[i]):
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# send the NoteOff message that matches with the octave[i] array
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# along with the velocity value
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midi.send(NoteOff(octave[i], velocity))
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# note state is updated
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note_states[i] = False
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# delay to settle MIDI data
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time.sleep(0.001)
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# delay to settle MIDI data
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time.sleep(0.005)

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