Update PulseIO examples

examples/pulse_io/buzzer.rb

@@ -4,8 +4,10 @@
 require 'bundler/setup'
 require 'denko'
 
-board = Denko::Board.new(Denko::Connection::Serial.new)
-buzzer = Denko::PulseIO::Buzzer.new(board: board, pin: 9)
+PIN    = 9
+
+board  = Denko::Board.new(Denko::Connection::Serial.new)
+buzzer = Denko::PulseIO::Buzzer.new(board: board, pin: PIN)
 
 C4 = 262
 D4 = 294
@@ -17,13 +19,16 @@
         [E4, 1], [D4, 1], [C4, 1], [D4, 1], [E4, 1], [E4, 1], [E4, 1], [E4, 1],
         [D4, 1], [D4, 1], [E4, 1], [D4, 1], [C4, 4],
         ]
-        
+
 bpm = 240
 beat_time = 60.to_f / bpm
 
 notes.each do |note|
   buzzer.tone(note[0])
   sleep note[1] * beat_time
+
+  # Stop for a bit so notes are properly defined.
+  buzzer.stop; sleep 0.010
 end
 
 buzzer.stop

examples/pulse_io/ir_output.rb

@@ -18,6 +18,8 @@
 require 'bundler/setup'
 require 'denko'
 
+PIN = 4
+
 # Note: If testing with 2 boards on one computer, be explicit about which serial device
 # runs denko. Use the second Serial.new call below and modify device: as needed.
 # Monitor the receiver board in the Arduino (or some other) serial monitor.
@@ -31,7 +33,7 @@
 # with other hardware or libraries. Try different pins. For more info:
 # https://github.com/Arduino-IRremote/Arduino-IRremote?#timer-and-pin-usage
 #
-ir = Denko::PulseIO::IROutput.new(board: board, pin: 4)
+ir = Denko::PulseIO::IROutput.new(board: board, pin: PIN)
 
 # NEC Raw-Data=0xF708FB04. LSBFIRST, so the binary for each hex digit below is backward.
 code =  [ 9000, 4500,                                 # Start bit

examples/pulse_io/pwm_output.rb

@@ -1,12 +1,15 @@
 #
-# Example configuring PWM frequency and resolution. Only on ESP32 for now.
+# PWM (pulse width modulation) output demo.
+# Frequency and resolution are configurable (only on ESP32 and PiBoard/Linux for now).
 # Capture output with logic analyzer or oscilloscope to verify accuracy.
 #
 require 'bundler/setup'
 require 'denko'
 
+PIN = 2
+
 board = Denko::Board.new(Denko::Connection::Serial.new)
-pwm = Denko::PulseIO::PWMOutput.new(board: board, pin: 2)
+pwm = Denko::PulseIO::PWMOutput.new(board: board, pin: PIN)
 
 # Resolution test: ~1% duty at 1 kHz / 10-bit.
 # On and off approx. 10us and 990us respectively.