peterc · February 27, 2012 00:32 · Feb 27, 2012 · Feb 27, 2012 · Feb 27, 2012 · Feb 27, 2012
diff --git a/16step.coffee b/16step.coffee
@@ -48,7 +48,10 @@ class DrumMachine
 
   playNote: (note, velocity, duration) ->
     return unless @playing
-    console.log "#{note} : #{velocity} : #{duration}ms"
+    velocity += Math.floor(Math.random() * 20) - 10
+    velocity = 0 if velocity < 0
+    velocity = 127 if velocity > 127
+    console.log "#{note}\t#{("*" for x in [0..(velocity / 7)]).join('')}"
     @midi.sendMessage [144, @instruments[note], velocity]
     setTimeout =>
       @stopNote note
@@ -64,7 +67,7 @@ class DrumMachine
       @currentStep++
       @currentStep = 1 if @currentStep == @totalSteps + 1
       clearInterval lp unless @playing
-    , this.barDuration() / @totalSteps
+    , (this.barDuration() / @totalSteps)
 
   set: (instrument, steps, velocity = 127) ->
     @steps[step - 1].push [instrument, velocity] for step in steps

diff --git a/16step.coffee b/16step.coffee
@@ -59,11 +59,11 @@ class DrumMachine
 
   play: ->
     @playing = true
-    @loop = setInterval =>
+    lp = setInterval =>
       @playStep @currentStep - 1
       @currentStep++
       @currentStep = 1 if @currentStep == @totalSteps + 1
-      clearInterval @loop unless @playing
+      clearInterval lp unless @playing
     , this.barDuration() / @totalSteps
 
   set: (instrument, steps, velocity = 127) ->
@@ -89,7 +89,7 @@ catch error
   midiOut.openVirtualPort ''
 
 dm = new DrumMachine(midiOut)
-dm.bpm = 120
+dm.bpm = 96
 
 # dm.set <instrument>, <step nos> (, <velocity>)
 dm.set 'hihat', [1, 3, 5, 7, 9, 11, 13, 15], 100

diff --git a/16step.coffee b/16step.coffee
@@ -29,7 +29,8 @@ class DrumMachine
     @playing = false
     @bpm = 160
     @currentStep = 1
-    @steps = ([] for i in [0..15])
+    @totalSteps = 16                # changeable for different time signatures
+    @steps = ([] for i in [1..64])
 
   instruments:
     kick: 36
@@ -61,9 +62,9 @@ class DrumMachine
     @loop = setInterval =>
       @playStep @currentStep - 1
       @currentStep++
-      @currentStep = 1 if @currentStep == 17
+      @currentStep = 1 if @currentStep == @totalSteps + 1
       clearInterval @loop unless @playing
-    , this.barDuration() / 16
+    , this.barDuration() / @totalSteps
 
   set: (instrument, steps, velocity = 127) ->
     @steps[step - 1].push [instrument, velocity] for step in steps
@@ -88,7 +89,7 @@ catch error
   midiOut.openVirtualPort ''
 
 dm = new DrumMachine(midiOut)
-dm.bpm = 93
+dm.bpm = 120
 
 # dm.set <instrument>, <step nos> (, <velocity>)
 dm.set 'hihat', [1, 3, 5, 7, 9, 11, 13, 15], 100

diff --git a/watchr b/watchr
@@ -0,0 +1,16 @@
+# watchr file to live restart the drum machine when changes
+# are made to the code. Perhaps there's a better way of doing
+# this.. let me know!
+#
+# To use, you need Ruby, gem install watchr, and run 
+# watchr <filename of this>
+
+$running_pid = nil
+
+watch('.*\.coffee') do |md|
+  Process.kill("INT", $running_pid) if $running_pid
+
+  $running_pid = fork do
+    exec("coffee", md[0])
+  end
+end
diff --git a/16step.coffee b/16step.coffee
@@ -34,8 +34,10 @@ class DrumMachine
   instruments:
     kick: 36
     hihat: 42
+    clap: 39
     snare: 40
     cowbell: 56
+    crash: 49
 
   barDuration: ->
     60000 / @bpm * 4
@@ -93,8 +95,13 @@ dm.set 'hihat', [1, 3, 5, 7, 9, 11, 13, 15], 100
 dm.set 'hihat', [2, 4, 6, 8, 10, 12, 14, 16], 39
 dm.set 'kick', [1, 4, 7, 11]
 dm.set 'snare', [5, 13]
+
+# extra bits added for fun
 dm.set 'cowbell', [2, 4, 7, 12], 20
 dm.set 'cowbell', [3, 5, 8, 13], 80
+dm.set 'crash', [15], 20
+dm.set 'clap', [5, 13], 80
+dm.set 'clap', [16], 50
 
 dm.play()
 

diff --git a/16step.coffee b/16step.coffee
@@ -35,6 +35,7 @@ class DrumMachine
     kick: 36
     hihat: 42
     snare: 40
+    cowbell: 56
 
   barDuration: ->
     60000 / @bpm * 4
@@ -92,6 +93,8 @@ dm.set 'hihat', [1, 3, 5, 7, 9, 11, 13, 15], 100
 dm.set 'hihat', [2, 4, 6, 8, 10, 12, 14, 16], 39
 dm.set 'kick', [1, 4, 7, 11]
 dm.set 'snare', [5, 13]
+dm.set 'cowbell', [2, 4, 7, 12], 20
+dm.set 'cowbell', [3, 5, 8, 13], 80
 
 dm.play()
 

diff --git a/16step.coffee b/16step.coffee
@@ -19,6 +19,10 @@
 #
 #   Yeah, not great OOD for real, but just a fun Sunday night
 #   project for now :-)
+#
+#   P.S. This is my first CoffeeScript in > 1 year so I have NO IDEA
+#   if I'm even vaguely doing it right. But it works. Please leave
+#   comments with code improvements to help me learn!
 
 class DrumMachine
   constructor: (@midi) ->

diff --git a/16step.coffee b/16step.coffee
@@ -4,6 +4,8 @@
 #   Inspired by Giles Bowkett's screencast at
 #   http://gilesbowkett.blogspot.com/2012/02/making-music-with-javascript-is-easy.html
 #
+#   Screencast demo of this code at http://www.youtube.com/watch?v=qWKkEaKL6DQ
+#
 # Required:
 #   node, npm and coffee-script installed
 #

diff --git a/16beat.coffee → 16step.coffee b/16beat.coffee → 16step.coffee
diff --git a/16beat.coffee b/16beat.coffee
@@ -1,4 +1,4 @@
-# Simple 16 beat drum machine experiment with Node and CoffeeScript
+# Simple 16 step drum machine experiment with Node and CoffeeScript
 #   by Peter Cooper - @peterc
 #
 #   Inspired by Giles Bowkett's screencast at
@@ -13,7 +13,7 @@
 #   create a software instrument (ideally a "drum kit")
 #   run this script with "coffee [filename]"
 #   ctrl+c to exit
-#   customize the drum beat at the footer of this file
+#   customize the drum steps at the footer of this file
 #
 #   Yeah, not great OOD for real, but just a fun Sunday night
 #   project for now :-)
@@ -22,8 +22,8 @@ class DrumMachine
   constructor: (@midi) ->
     @playing = false
     @bpm = 160
-    @currentBeat = 1
-    @beats = ([] for i in [0..15])
+    @currentStep = 1
+    @steps = ([] for i in [0..15])
 
   instruments:
     kick: 36
@@ -44,27 +44,27 @@ class DrumMachine
       @stopNote note
     , duration
 
-  playBeat: (beat) ->
-    @playNote(note[0], note[1], 40) for note in @beats[beat]
+  playStep: (step) ->
+    @playNote(note[0], note[1], 40) for note in @steps[step]
 
   play: ->
     @playing = true
     @loop = setInterval =>
-      @playBeat @currentBeat - 1
-      @currentBeat++
-      @currentBeat = 1 if @currentBeat == 17
+      @playStep @currentStep - 1
+      @currentStep++
+      @currentStep = 1 if @currentStep == 17
       clearInterval @loop unless @playing
     , this.barDuration() / 16
 
-  set: (instrument, beats, velocity = 127) ->
-    @beats[beat - 1].push [instrument, velocity] for beat in beats
+  set: (instrument, steps, velocity = 127) ->
+    @steps[step - 1].push [instrument, velocity] for step in steps
 
   pause: ->
     @playing = false
 
   stop: ->
     @pause()
-    @currentBeat = 1
+    @currentStep = 1
     @midi.sendMessage [252, 0, 0]
     @midi.sendMessage [176, 123, 0]
 
@@ -79,13 +79,13 @@ catch error
   midiOut.openVirtualPort ''
 
 dm = new DrumMachine(midiOut)
-dm.bpm = 240
+dm.bpm = 93
 
-# dm.set <instrument>, <beat nos> (, <velocity>)
+# dm.set <instrument>, <step nos> (, <velocity>)
 dm.set 'hihat', [1, 3, 5, 7, 9, 11, 13, 15], 100
 dm.set 'hihat', [2, 4, 6, 8, 10, 12, 14, 16], 39
 dm.set 'kick', [1, 4, 7, 11]
-dm.set 'snare', [5, 13, 7, 9, 14, 15]
+dm.set 'snare', [5, 13]
 
 dm.play()
 

diff --git a/16beat.coffee b/16beat.coffee
@@ -79,13 +79,13 @@ catch error
   midiOut.openVirtualPort ''
 
 dm = new DrumMachine(midiOut)
-dm.bpm = 93
+dm.bpm = 240
 
 # dm.set <instrument>, <beat nos> (, <velocity>)
-dm.set 'kick', [1, 4, 7, 11]
-dm.set 'snare', [5, 13]
 dm.set 'hihat', [1, 3, 5, 7, 9, 11, 13, 15], 100
 dm.set 'hihat', [2, 4, 6, 8, 10, 12, 14, 16], 39
+dm.set 'kick', [1, 4, 7, 11]
+dm.set 'snare', [5, 13, 7, 9, 14, 15]
 
 dm.play()
 

diff --git a/16beat.coffee b/16beat.coffee
@@ -1,22 +1,22 @@
 # Simple 16 beat drum machine experiment with Node and CoffeeScript
 #   by Peter Cooper - @peterc
 #
-# Inspired by Giles Bowkett's screencast at
-# http://gilesbowkett.blogspot.com/2012/02/making-music-with-javascript-is-easy.html
+#   Inspired by Giles Bowkett's screencast at
+#   http://gilesbowkett.blogspot.com/2012/02/making-music-with-javascript-is-easy.html
 #
 # Required:
 #   node, npm and coffee-script installed
 #
-# To use:
+# To run:
 #   npm install midi
 #   run up Garageband
-#   create a software instrument (ideally a drum kit)
+#   create a software instrument (ideally a "drum kit")
 #   run this script with "coffee [filename]"
 #   ctrl+c to exit
 #   customize the drum beat at the footer of this file
 #
-# Yeah, not great OOD for real, but just a fun Sunday night
-# project for now :-)
+#   Yeah, not great OOD for real, but just a fun Sunday night
+#   project for now :-)
 
 class DrumMachine
   constructor: (@midi) ->

diff --git a/16beat.coffee b/16beat.coffee
@@ -14,6 +14,9 @@
 #   run this script with "coffee [filename]"
 #   ctrl+c to exit
 #   customize the drum beat at the footer of this file
+#
+# Yeah, not great OOD for real, but just a fun Sunday night
+# project for now :-)
 
 class DrumMachine
   constructor: (@midi) ->

diff --git a/16beat.coffee b/16beat.coffee
@@ -15,16 +15,6 @@
 #   ctrl+c to exit
 #   customize the drum beat at the footer of this file
 
-midi = require 'midi'
-midiOut = new midi.output
-
-try
-  midiOut.openPort(0)
-catch error
-  midiOut.openVirtualPort ''
-
-# -----
-
 class DrumMachine
   constructor: (@midi) ->
     @playing = false
@@ -77,6 +67,14 @@ class DrumMachine
 
 # -----
 
+midi = require 'midi'
+midiOut = new midi.output
+
+try
+  midiOut.openPort(0)
+catch error
+  midiOut.openVirtualPort ''
+
 dm = new DrumMachine(midiOut)
 dm.bpm = 93
 

diff --git a/16beat.coffee b/16beat.coffee
@@ -14,16 +14,14 @@
 #   run this script with "coffee [filename]"
 #   ctrl+c to exit
 #   customize the drum beat at the footer of this file
-#
-# Troubleshooter:
-#   No sound? Switch the comments around on the midiOut.openVirtualPort lines below.
-#   You probably don't have IAC enabled. (Or use Audio MIDI Setup to enable it..)
 
 midi = require 'midi'
 midiOut = new midi.output
 
-#midiOut.openVirtualPort ''  # use this line if you have problems
-midiOut.openPort(0)          # if you have IAC turned on in Audio Midi Setup, this is nicer
+try
+  midiOut.openPort(0)
+catch error
+  midiOut.openVirtualPort ''
 
 # -----
 

diff --git a/16beat.coffee b/16beat.coffee
@@ -18,10 +18,14 @@
 # Troubleshooter:
 #   No sound? Switch the comments around on the midiOut.openVirtualPort lines below.
 #   You probably don't have IAC enabled. (Or use Audio MIDI Setup to enable it..)
-#
-# Notes:
-#   Yep, this is scrappy and unstructured. Just a bit of fun on a
-#   Sunday night :-)
+
+midi = require 'midi'
+midiOut = new midi.output
+
+#midiOut.openVirtualPort ''  # use this line if you have problems
+midiOut.openPort(0)          # if you have IAC turned on in Audio Midi Setup, this is nicer
+
+# -----
 
 class DrumMachine
   constructor: (@midi) ->
@@ -43,7 +47,7 @@ class DrumMachine
 
   playNote: (note, velocity, duration) ->
     return unless @playing
-    console.log "Playing note #{note} at #{velocity} for #{duration}ms"
+    console.log "#{note} : #{velocity} : #{duration}ms"
     @midi.sendMessage [144, @instruments[note], velocity]
     setTimeout =>
       @stopNote note
@@ -73,13 +77,7 @@ class DrumMachine
     @midi.sendMessage [252, 0, 0]
     @midi.sendMessage [176, 123, 0]
 
-# ----------------------------------------------
-
-midi = require 'midi'
-midiOut = new midi.output
-
-#midiOut.openVirtualPort ''  # use this line if you have problems
-midiOut.openPort(0)          # if you have IAC turned on in Audio Midi Setup, this is nicer
+# -----
 
 dm = new DrumMachine(midiOut)
 dm.bpm = 93

diff --git a/16beat.coffee b/16beat.coffee
@@ -27,6 +27,7 @@ class DrumMachine
   constructor: (@midi) ->
     @playing = false
     @bpm = 160
+    @currentBeat = 1
     @beats = ([] for i in [0..15])
 
   instruments:
@@ -48,24 +49,27 @@ class DrumMachine
       @stopNote note
     , duration
 
-  playBeat: ->
-    @playNote(note[0], note[1], 40) for note in @beats[@currentBeat - 1]
+  playBeat: (beat) ->
+    @playNote(note[0], note[1], 40) for note in @beats[beat]
 
   play: ->
     @playing = true
-    @currentBeat = 1
-    setInterval =>
-      @playBeat()
+    @loop = setInterval =>
+      @playBeat @currentBeat - 1
       @currentBeat++
       @currentBeat = 1 if @currentBeat == 17
+      clearInterval @loop unless @playing
     , this.barDuration() / 16
 
-
-  set: (instrument, beat, velocity = 127) ->
-    @beats[beat - 1].push [instrument, velocity]
+  set: (instrument, beats, velocity = 127) ->
+    @beats[beat - 1].push [instrument, velocity] for beat in beats
+
+  pause: ->
+    @playing = false
 
   stop: ->
-    @playing = false
+    @pause()
+    @currentBeat = 1
     @midi.sendMessage [252, 0, 0]
     @midi.sendMessage [176, 123, 0]
 
@@ -78,19 +82,13 @@ midiOut = new midi.output
 midiOut.openPort(0)          # if you have IAC turned on in Audio Midi Setup, this is nicer
 
 dm = new DrumMachine(midiOut)
-
 dm.bpm = 93
 
-dm.set 'kick', 1
-dm.set 'kick', 4
-dm.set 'kick', 7
-dm.set 'kick', 11
-
-dm.set 'snare', 5
-dm.set 'snare', 13
-
-dm.set 'hihat', beat, 100 for beat in [1, 3, 5, 7, 9, 11, 13, 15]
-dm.set 'hihat', beat, 39 for beat in [2, 4, 6, 8, 10, 12, 14, 16]
+# dm.set <instrument>, <beat nos> (, <velocity>)
+dm.set 'kick', [1, 4, 7, 11]
+dm.set 'snare', [5, 13]
+dm.set 'hihat', [1, 3, 5, 7, 9, 11, 13, 15], 100
+dm.set 'hihat', [2, 4, 6, 8, 10, 12, 14, 16], 39
 
 dm.play()
 

diff --git a/16beat.coffee b/16beat.coffee
@@ -0,0 +1,99 @@
+# Simple 16 beat drum machine experiment with Node and CoffeeScript
+#   by Peter Cooper - @peterc
+#
+# Inspired by Giles Bowkett's screencast at
+# http://gilesbowkett.blogspot.com/2012/02/making-music-with-javascript-is-easy.html
+#
+# Required:
+#   node, npm and coffee-script installed
+#
+# To use:
+#   npm install midi
+#   run up Garageband
+#   create a software instrument (ideally a drum kit)
+#   run this script with "coffee [filename]"
+#   ctrl+c to exit
+#   customize the drum beat at the footer of this file
+#
+# Troubleshooter:
+#   No sound? Switch the comments around on the midiOut.openVirtualPort lines below.
+#   You probably don't have IAC enabled. (Or use Audio MIDI Setup to enable it..)
+#
+# Notes:
+#   Yep, this is scrappy and unstructured. Just a bit of fun on a
+#   Sunday night :-)
+
+class DrumMachine
+  constructor: (@midi) ->
+    @playing = false
+    @bpm = 160
+    @beats = ([] for i in [0..15])
+
+  instruments:
+    kick: 36
+    hihat: 42
+    snare: 40
+
+  barDuration: ->
+    60000 / @bpm * 4
+
+  stopNote: (note) ->
+    @midi.sendMessage [128, note, 0]
+
+  playNote: (note, velocity, duration) ->
+    return unless @playing
+    console.log "Playing note #{note} at #{velocity} for #{duration}ms"
+    @midi.sendMessage [144, @instruments[note], velocity]
+    setTimeout =>
+      @stopNote note
+    , duration
+
+  playBeat: ->
+    @playNote(note[0], note[1], 40) for note in @beats[@currentBeat - 1]
+
+  play: ->
+    @playing = true
+    @currentBeat = 1
+    setInterval =>
+      @playBeat()
+      @currentBeat++
+      @currentBeat = 1 if @currentBeat == 17
+    , this.barDuration() / 16
+
+
+  set: (instrument, beat, velocity = 127) ->
+    @beats[beat - 1].push [instrument, velocity]
+
+  stop: ->
+    @playing = false
+    @midi.sendMessage [252, 0, 0]
+    @midi.sendMessage [176, 123, 0]
+
+# ----------------------------------------------
+
+midi = require 'midi'
+midiOut = new midi.output
+
+#midiOut.openVirtualPort ''  # use this line if you have problems
+midiOut.openPort(0)          # if you have IAC turned on in Audio Midi Setup, this is nicer
+
+dm = new DrumMachine(midiOut)
+
+dm.bpm = 93
+
+dm.set 'kick', 1
+dm.set 'kick', 4
+dm.set 'kick', 7
+dm.set 'kick', 11
+
+dm.set 'snare', 5
+dm.set 'snare', 13
+
+dm.set 'hihat', beat, 100 for beat in [1, 3, 5, 7, 9, 11, 13, 15]
+dm.set 'hihat', beat, 39 for beat in [2, 4, 6, 8, 10, 12, 14, 16]
+
+dm.play()
+
+process.addListener "SIGTERM", ->
+  dm.stop
+  midiOut.closePort()