Add support for 4-pin range sensors, the velocity sensor, and LED status.

FossilOrigin-Name: ab34614152b3a25488aa4b55c45ec4a6f625bde42cd794209464825bb7654040

theremin/lib/fluidsynth.rb

@@ -48,11 +48,13 @@ class FluidSynth
 	end
 
 
+	### Instance a new fluidsynth interface.
+	###
 	def initialize( host=DEFAULT_HOST, port=DEFAULT_PORT )
 		@host = host
 		@port = port
 		@lastnote = nil
-		@velocity = 80
+		@velocity = 0
 	end
 
 	# The TCP socket to fluidsynth.
@@ -96,6 +98,14 @@ class FluidSynth
 	end
 
 
+	### Select a loaded soundfont and instrument by index.
+	### (Always using channel 0.)
+	###
+	def instrument( font_idx, instrument_idx )
+		self.send "select 0 #{font_idx} 0 #{instrument_idx}"
+	end
+
+
 	### Turn glide (portamento) on or off.  Val is an integer that
 	### represents 128ms.  4 == 512ms.
 	###
@@ -132,13 +142,6 @@ class FluidSynth
 	end
 
 
-	### Selects an instrument +index+ within the currently loaded sf2 for channel 0.
-	###
-	def instrument( index )
-		self.send "select 0 1 0 #{index}"
-	end
-
-
 	### Loads a resource (sf2, etc) from +path+.
 	###
 	def load( path )

theremin/lib/gpio.rb

@@ -37,7 +37,7 @@ class GPIO
 			value:     BASE + "gpio#{pin}" + "value"
 		}
 
-		self.export rescue Errno::EBUSY nil
+		self.export rescue nil
 	end
 
 	# The GPIO PIN number.

theremin/lib/theremin.rb

@@ -1,6 +1,7 @@
 # -*- ruby -*-
 # vim: set noet sta sw=4 ts=4 :
 
+require 'pathname'
 require 'forwardable'
 require 'configurability'
 require 'loggability'
@@ -17,7 +18,11 @@ class Theremin
 		Forwardable
 
 	# The speed of sound, in centmeters/sec.
-    SONICSPEED = 34300
+	SONICSPEED = 34300
+
+	# The soundfont that is loaded to index 1.
+	DEFAULT_FONT = Pathname.pwd + 'Theremin.sf2'
+
 
 	# Loggability API
 	log_as :theremin
@@ -62,6 +67,7 @@ class Theremin
 		# The soundfont to use for the synth.  Will look in the
 		# current working directory by default, but absolute paths 
 		# can be used for system sounds.
+		# The "Theremin.sf2" soundfont is always loaded into index 1!
 		setting :font, default: 'Theremin.sf2' do |val|
 			val = Pathname( val )
 			val = Pathname.pwd + val unless val.absolute?
@@ -75,7 +81,7 @@ class Theremin
 
 		##
 		# A reasonable distance in feet for the theremin to map notes.
-		setting :distance_max, default: 4
+		setting :distance_max, default: 3
 
 		##
 		# Initial synth volume.
@@ -90,7 +96,11 @@ class Theremin
 		setting :chorus, default: true
 
 		##
-		# What instrument to use from the loaded SF2.
+		# What font to initially use. 1 is the theremin. 2 is user loaded.
+		setting :font_index, default: 1
+
+		##
+		# What instrument to initially use from the loaded SF2.
 		setting :instrument_index, default: 1
 
 		##
@@ -118,16 +128,14 @@ class Theremin
 	### Instance a new Theremin daemon.
 	###
 	def initialize
-		# TODO: @pins = %i[ pitch_trigger pitch_echo velocity_trigger velocity_echo ]
-		@pins = %i[ pitch_trigger ]
-
-		self.setup_gpio
-
+		@pins    = %i[ pitch_trigger pitch_echo velocity_trigger velocity_echo ]
 		@timeout = 0
 		@synth   = FluidSynth.new( self.class.host, self.class.port )
 		@running = false
 		@threads = []
 
+		self.setup_gpio
+
 	rescue => err
 		self.log.warn( err.message )
 		self.stop rescue nil
@@ -154,12 +162,15 @@ class Theremin
 
 		self.gain( self.class.gain )
 		self.glide( self.class.glide )
-		self.load( self.class.font.to_s )
+		self.load( DEFAULT_FONT )
+		self.load( self.class.font.to_s ) unless self.class.font == DEFAULT_FONT
 		self.reverb( self.class.reverb )
 		self.chorus( self.class.chorus )
-		self.instrument( self.class.instrument_index )
+		self.instrument( self.class.font_index, self.class.instrument_index )
 
 		@threads << self.note_thread
+		@threads << self.velocity_thread
+		self.led( :green )
 		self.log.warn "Waiting for interaction, or ctrl-c to exit."
 		@threads.map( &:join )
 	end
@@ -171,6 +182,7 @@ class Theremin
 		@running = false
 		self.pins.each {|pin| self.class.send( pin ).unexport rescue nil }
 		self.synth.socket.close
+		self.led( :red )
 	end
 
     
@@ -187,12 +199,12 @@ class Theremin
 		]
 
 		return self.running_thread do
-			distance = self.distance
+			distance = self.distance( :pitch )
 			note = self.distance_to_note( distance )
 
 			# Only play if within maximum distance.
 			#
-			if distance <= self.class.distance_max
+			if distance > 0 && distance <= self.class.distance_max
 				self.log.debug "Pitch distance %0.2f (note %s)" % [ distance, note ]
 
 				# Hold the note if it is unchanged within slew amount.
@@ -218,6 +230,32 @@ class Theremin
 	end
 
 
+	### Measure velocity distance, convert for synth notes.
+	###
+	def velocity_thread
+		self.log.info "Starting velocity measurements (every %s/sec) within %d feet." % [
+			self.class.sample_interval,
+			self.class.distance_max
+		]
+
+		return self.running_thread do
+			distance = self.distance( :velocity )
+			velocity = self.distance_to_velocity( distance )
+
+			# Only set if within maximum distance.
+			#
+			if distance > 0 && distance <= self.class.distance_max
+				self.log.debug "Velocity distance %0.2f (velocity %s)" % [ distance, velocity ]
+				synth.velocity = velocity
+			else
+				synth.velocity = 0
+			end
+
+			sleep self.class.sample_interval
+		end
+	end
+
+
 	### Create a new thread loop that returns when @running is false.
 	###
 	def running_thread( &block )
@@ -239,9 +277,12 @@ class Theremin
 			raise "GPIO pins are required configuration options: %p" % [ self.pins ]
 		end
 
-		self.class.pitch_trigger.edge( :both )
-		# self.class.pitch_echo.edge( :both )
-		# TODO: self.class.velocity_echo.edge( :both )
+		self.class.pitch_trigger.mode( :out )
+		self.class.velocity_trigger.mode( :out )
+		self.class.pitch_echo.mode( :in )
+		self.class.pitch_echo.edge( :both )
+		self.class.velocity_echo.mode( :in )
+		self.class.velocity_echo.edge( :both )
 	end
 
 
@@ -258,22 +299,35 @@ class Theremin
 	end
 
 
-	### TODO: make generic for a trigger/echo pin pair
-	### Returns detected distance in feet.
+	### For a given +distance+ in feet, convert into a velocity range (0-127).
 	###
-	def distance
-		self.class.pitch_trigger.mode( :out )
-		self.class.pitch_trigger.write( 1 )
+	def distance_to_velocity( distance )
+		velocity_start = 127
+		velocity_end   = 1
+		distance_min   = 0
+
+		slope = 1.0 * ( velocity_end - velocity_start ) / ( self.class.distance_max - distance_min )
+		return velocity_start + ( slope * ( distance - distance_min ) ).round
+	end
+
+
+
+	### Returns detected distance in feet for a given +device+.
+	###
+	def distance( device )
+		device_trigger = self.class.send( "#{device}_trigger".to_sym )
+		device_echo    = self.class.send( "#{device}_echo".to_sym )
+
+		device_trigger.write( 1 )
 		sleep 0.00001
-		self.class.pitch_trigger.write( 0 )
-		self.class.pitch_trigger.mode( :in )
+		device_trigger.write( 0 )
 
 		duration = Time.now
-		while self.class.pitch_trigger.read == 0
+		while device_echo.read == 0
 			starttime = Time.now
 			break if starttime - duration > GPIO::TIMEOUT
 		end
-		while self.class.pitch_trigger.read == 1
+		while device_echo.read == 1
 			stoptime = Time.now
 			break if stoptime - duration > GPIO::TIMEOUT
 		end
@@ -289,5 +343,20 @@ class Theremin
 	rescue
 		return 0
 	end
-end
+
+
+	### Set the LED.  Maybe it'll be visible.
+	###
+	def led( color )
+		case color
+		when :red
+			File.open( '/sys/class/leds/led0/brightness', 'w' ){|l| l.puts(0) }
+			File.open( '/sys/class/leds/led1/brightness', 'w' ){|l| l.puts(1) }
+		when :green
+			File.open( '/sys/class/leds/led0/brightness', 'w' ){|l| l.puts(1) }
+			File.open( '/sys/class/leds/led1/brightness', 'w' ){|l| l.puts(0) }
+		end
+	end
+
+end # class Theremin