init

Makefile

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+
+.PHONY: all
+
+all: flash
+
+flash:
+	cp code.py /Volumes/CIRCUITPY/

blinky.py

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+# import board
+# import digitalio
+# import time
+#
+# led = digitalio.DigitalInOut(board.LED)
+# led.direction = digitalio.Direction.OUTPUT
+#
+# while True:
+#     print("Hello, CircuitPython!")
+#     led.value = True
+#     time.sleep(0.1)
+#     led.value = False
+#     time.sleep(0.1)

code.py

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+# MIDI Cable
+# Black - Data
+# White - VCC 3.3v
+# Brown - GND
+
+import time
+import board
+import busio
+import adafruit_midi
+
+from adafruit_midi.control_change import ControlChange
+from adafruit_midi.note_off import NoteOff
+from adafruit_midi.note_on import NoteOn
+
+
+def init():
+    print("init")
+    global midi
+    uart = busio.UART(board.TX, board.RX, baudrate=31250, timeout=0.001)  # init UART
+    midi_in_channel = 2
+    midi_out_channel = 1
+    midi = adafruit_midi.MIDI(
+        midi_in=uart,
+        midi_out=uart,
+        in_channel=(midi_in_channel - 1),
+        out_channel=(midi_out_channel - 1),
+        debug=False,
+    )
+    print("Default output channel:", midi.out_channel + 1)
+
+
+def trig(note_nr):
+    # print("trig: " + str(note_nr))
+    midi.send(NoteOn(note_nr, 127))
+    midi.send(NoteOff(note_nr, 0))
+
+
+def subdiv(clk_bar, clk_bar_old, div, note_nr):
+    div_ns = div_to_ns(div)
+    clk_sub1_old = clk_bar_old % div_ns
+    clk_sub1 = clk_bar % div_ns
+    clk_sub1_diff = clk_sub1 - clk_sub1_old
+    if clk_sub1_diff < 0:
+        trig(note_nr)
+
+
+def div_to_ns(div) -> int:
+    clk_pulse_per_second = 1000000000
+    beat_per_bar = 4
+    bar_ns = beat_per_bar / bpm * 60 * clk_pulse_per_second
+    return bar_ns / div
+
+
+def main():
+    print("main")
+    bar_ns = div_to_ns(1)
+
+    clk_bar = time.monotonic_ns() % bar_ns
+    while True:
+        clk_bar_old = clk_bar
+        clk_bar = time.monotonic_ns() % bar_ns
+
+        # for i in range(1,4):
+        #     subdiv(clk_bar, clk_bar_old, i, 36+i)
+        subdiv(clk_bar, clk_bar_old, 1, 36)
+        subdiv(clk_bar, clk_bar_old, 2, 37)
+        subdiv(clk_bar, clk_bar_old, 4, 38)
+        subdiv(clk_bar, clk_bar_old, 8, 39)
+        subdiv(clk_bar, clk_bar_old, 16, 40)
+
+bpm = 80
+
+init()
+main()