#!/usr/bin/env ruby
# encoding: UTF-8
# tested with ruby 1.9.1 and 1.9.3
# USB IR Toy tool
# based on http://dangerousprototypes.com/docs/USB_IR_Toy:_Sampling_mode
require 'serialport'

# display debug messages
@debug = false

def help
  puts "USB IR Toy tool"
  puts ""
  puts "option:"
  puts "\t--help,-h\t\tdisplay this help"
  puts "\t--device,-d <device>\tuse this serial port"
  puts "\t--record,-r <file>\trecord IR stream into this file"
  puts "\t--play,-p <file>\tplay IR activity from this file"
  puts "\t--freq,-f\t\tdetect frequency of IR signal"
  puts "\t--laser,-l\t\tuse lasertag frequency (56kHz) when transmitting"
  puts "\t--traffic,-t\t\tshow communication traffic with USB IR toy"
  exit 0
end

device = "/dev/ttyACM0"
mode = :record
file = nil
fast = false # false = default 38.4kHz, true = 56kHz
while argument = ARGV.shift do
  case argument
  when "--help","-h"
    help
  when "--device","-d"
    raise "no device specified" unless device = ARGV.shift
  when "--record","-r"
    raise "no file specified" unless file = ARGV.shift
    file = File.open(file,"w")
    mode = :record
  when "--play","-p"
    raise "no file specified" unless file = ARGV.shift
    file = File.open(file,"r")
    mode = :play
  when "--freq","-f"
    mode = :freq
  when "--laser","-l"
    fast = true
  when "--traffic","-t"
    @debug = true
  else
    help
  end
end

# read n bytes from serial
def read(bytes)
  data = @serial.read bytes
  str = "> "
  data.bytes {|b| str += "%02x " % b}
  puts str if @debug
  return data
end

# write data to serial
def write(data)
  to_send = nil
  to_send = case data
  when Fixnum
    [data].pack "C"
  when Array
    data.pack "C*"
  when String
    data
  else
    raise "unknown data format to send"
  end
  
  str = "< "
  to_send.bytes {|b| str += "%02x " % b}
  puts str if @debug

  @serial.write to_send
end

# open serial to USB IR Toy (adapt device path. any baudrate is accepted)
print "opening serial port #{device} … "
$stdout.flush
@serial = SerialPort.new(device,115200)
@serial.read_timeout = 0
puts "✓"

print "reseting … "
$stdout.flush
# empty buffer
@serial.read_timeout = 500
loop while @serial.read(1)
@serial.read_timeout = 0
5.times do
  write [0x00]
end
puts "✓"
sleep 0.5

print "getting version … "
$stdout.flush
write 'v'
@serial.read_timeout = 500
version = read 4
@serial.read_timeout = 0
if version and version.length==4 then
  puts "HW v#{version[1,1]}, FW v#{version[2,2]}"
else
  puts "USB IR Toy is stuck. un- and re-plug it"
  exit 0
end

print "enter sampling mode … "
$stdout.flush
write 's'
protocol = nil
begin
  protocol = read 3
end until protocol and protocol.length==3
puts "protocol version: #{protocol}"

case mode
when :record
  STATES = ["–","_"]
  state = 0
  unit = 21.3333 #us
  loop do
    data = read 2
    time = data.unpack('n')[0]
    if time==0xffff then
      puts "|"
    else
      print "#{STATES[state%2]}#{(time*unit/100).round}#{STATES[state%2]}"
    end
    $stdout.flush
    state += 1
    file.write data if file
  end
when :play
  if fast then
    puts "setting transmit modulation to 56kHz used by lasertag"
    # use command http://dangerousprototypes.com/docs/USB_IR_Toy:_Sampling_mode#Setup_transmit_modulation_.280x06.29
    # use value from http://www.micro-examples.com/public/microex-navig/doc/097-pwm-calculator (55555.56kHz)
    write [0x06,0x35,0x00]
  end
  print "enter transmit mode (with handshake) … "
  $stdout.flush
  write 0x24 # enable by count report
  write 0x25 # notify on complete
  write 0x26 # handshake
  puts "✓"
  buffer = 0 # free buffer size
  burst = true # start new burst transmittion
  while data = file.read(2) do
    if burst then
      burst = false
      buffer = 0
      write 0x03 # transmit
      puts "transmitting burst"
    end
    # wait for free buffer
    if buffer<=0 then
      buffer=read(1).unpack("C")[0]
      puts "new buffer size: #{buffer}"
    end
    write data
    buffer -= data.size
    if data.unpack('n')[0]==0xffff then
      # restart transmit
      burst = true
      # last handshake(s) until count byte
      begin
        report = read(1)
        sleep 1
      end until report and report[0]=='t'
      # byte count
      count = read(2)
      puts "#{count[0,2].unpack('n')[0]} bytes processed"
      # notification
      case tmp=read(1)
      when "C"
        puts "transmission complete"
      when "F"
        puts "buffer underrun"
      else
        puts "unknown notification: #{tmp}"
      end
      sleep 1
    end
  end
when :freq
  print "waiting for a burst … "
  loop until read(2).unpack('n')[0]==0xffff
  $stdout.flush
  puts "✓"
  write 0x04
  data = read(8).unpack('n*')
  # PIC clock is 12MHz
  clock = 1.0/12E6
  freq1 = (1/(clock*(data[0])))/(1E3)
  freq2 = (1/(clock*(data[1]-data[0])))/(1E3)
  freq3 = (1/(clock*(data[2]-data[1])))/(1E3)
  puts "detected frequency: #{freq1.round(2)}kHz, #{freq2.round(2)}kHz, #{freq3.round(2)}kHz"
else
  puts "unknown mode #{mode}"
end