Initial implementation of midi led player

2 files changed, 137 insertions, 0 deletions

diff --git a/README.md b/README.md
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+Turris light organ
+==================
+Simple script to blink with Turris leds to music. There is for now only
+implementation using midi, but second implementation using wave and FFT is
+planned.
+
+midi
+----
+Requirements:
+
+* Python3
+* Python3-pip
+* mido (Can be installed using pip)
+
+```
+opkg update
+opkg install python3-pip
+pip3 install mido
+```
+
+Now you should be able to run `tlo-midi.py` script. Input must be midi file. If
+your midi file has more than one track, you might want to choose different one
+using `-c` option.
+
+Tested with following midi file: https://www.youtube.com/watch?v=6zCzeTUOBKg
diff --git a/tlo-midi.py b/tlo-midi.py
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+#!/usr/bin/env python3
+# This is simple script playing midi track on turris leds
+# Currently tested only with turris omnia
+
+import os
+import time
+import argparse
+import mido
+
+# Parse arguments
+parser = argparse.ArgumentParser(description='Turris leds midi track player')
+parser.add_argument('-c', nargs=1, type=int, help="Choose channel")
+parser.add_argument('-d', nargs=1, type=str, help="Color in format 0xFFF")
+parser.add_argument('-t', action='store_true',
+                    help="If it is test run (print output to console)")
+parser.add_argument('FILE', nargs=1, type=str, help="Midi audio file")
+args = parser.parse_args()
+
+midi_file = args.FILE[0]
+channel = 0
+if args.c is not None:
+    channel = args.c[0]
+test_run = False
+if args.t is not None:
+    test_run = args.t
+color = '0xF00'  # In default use red
+if args.d is not None:
+    color = args.d[0]
+
+# Load midi file
+midi = mido.MidiFile(midi_file)
+
+# Initialize data line (we have 12 leds)
+data_line = [0]*12
+# Found out cut off values (maximal and minimal note in input midi file to use
+# all leds to their fullest)
+cut_bottom = None
+cut_top = None
+for msg in midi:
+    if (msg.type == "note_on" or msg.type == "note_off") and \
+            msg.channel == channel:
+        if cut_bottom is None or msg.note < cut_bottom:
+            cut_bottom = msg.note
+        if cut_top is None or msg.note > cut_top:
+            cut_top = msg.note
+if cut_bottom is None or cut_top is None:
+    raise Exception("Midi file seems to contain no audio data")
+
+rainbow_led = (
+        'pwr',
+        'lan0',
+        'lan1',
+        'lan2',
+        'lan3',
+        'lan4',
+        'wan',
+        'pci1',
+        'pci2',
+        'pci3',
+        'usr1',
+        'usr2'
+        )
+
+
+def output_line():
+    "Function used for pushing data out"
+    if test_run:
+        line = ""
+        for i in range(0, 12):
+            # We divide velocity by 13 to ensure resolution of 0-9
+            # (velocity is 1..128)
+            line = line + str(int(data_line[i]/13))
+        print(line)
+    else:
+        cmd = "rainbow "
+        for i in range(0, 12):
+            cmd = cmd + rainbow_led[i] + " " + color + " intensity "
+            # Here range is from 0-100
+            cmd = cmd + str(int(data_line[i]/1.28)) + " "
+        os.system(cmd)
+
+
+def note_to_line(note):
+    """ This function calculates which led is for given note
+    Note is number from 0..255
+    """
+    note = note - cut_bottom
+    # Threshold between notes
+    threshold = (cut_top - cut_bottom) / 12
+    # Now divide note by threshold and shift it by 1 down for indexing
+    return int(note / threshold - 1)
+
+
+def note(note, velocity, time_suspend, off=False):
+    if off:
+        velocity = 0
+    time.sleep(time_suspend)  # Suspend for given delay
+    data_line[note_to_line(note)] = velocity
+
+
+# Now do the work
+for msg in midi:
+    if (msg.type == "note_on" or msg.type == "note_off") and \
+            msg.channel == channel:
+        note(msg.note, msg.velocity, msg.time, msg.type == "note_off")
+    else:
+        print("Ignoring message: " + str(msg))
+    output_line()
+
+# Note: We are not handling beats at all. This just waits for given time when it's
+# told to do that, but nothing special is done here with timing. This might be
+# enough for basic midi files, but problematic for slow and fast beats.