Class: Ev3dev::Led

Inherits:
Device show all
Defined in:
lib/ev3dev/led.rb

Constant Summary collapse

PATH = 
"/sys/class/leds"
GREEN = 
[255,   0]
RED = 
[  0, 255]
AMBER = 
[255, 255]
MAX_BRIGHTNESS = 
255

Instance Attribute Summary collapse

Attributes inherited from Device

#device_path

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Led

Returns a new instance of Led.



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# File 'lib/ev3dev/led.rb', line 13

def initialize()
  raise "couldn't find LED attributes" unless File.exist?(PATH)

  @left_green   = set_led_path("left" , "green")
  @left_red     = set_led_path("left" , "red"  )
  @right_green  = set_led_path("right", "green")
  @right_red    = set_led_path("right", "red"  )

  @default_paths  = [@left_green, @left_red, @right_green, @right_red]
  @left_paths     = [@left_green, @left_red]
  @right_paths    = [@right_green, @right_red]

  @paths = @default_paths
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args, &block) ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 127

def method_missing(name, *args, &block)
  raise "couldn't specify the left/right green/red LED" if @paths.size != 1
  @device_path = @paths[0]

  super
end

Instance Attribute Details

#paths ⇒ Object (readonly)

Returns the value of attribute paths.



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# File 'lib/ev3dev/led.rb', line 3

def paths
  @paths
end

Instance Method Details



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# File 'lib/ev3dev/led.rb', line 70

def blink(*args)
  args = args.flatten
  args = [MAX_BRIGHTNESS, MAX_BRIGHTNESS] if args.empty?
  set_each_trigger_brightness(@paths, "timer", args)

  if args.size == 3
    if @paths.size == 1
      @paths.each do |path|
        brightness = args[0]
        next if brightness == 0

        delay_on_time  = args[1]
        delay_off_time = args[2]

        write_value_with_check(path, "delay_on" , delay_on_time)
        write_value_with_check(path, "delay_off", delay_off_time)
      end
    else
      raise "ArgumentError: wrong number of arguments (3 for 4)"
    end
  end

  if args.size == 4
    @paths.each_with_index do |path, index|
      brightness = args[index % 2]
      next if brightness == 0

      delay_on_time  = args[2]
      delay_off_time = args[3]

      write_value_with_check(path, "delay_on" , delay_on_time)
      write_value_with_check(path, "delay_off", delay_off_time)
    end
  end

  @paths = @default_paths
end

#flash ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 119

def flash()
  raise "couldn't specify the left/right green/red LED" if @paths.size != 1
  path = @paths[0]
  write_value_to_file(path, "activate", 1)

  @paths = @default_paths
end

#left ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 28

def left()
  @paths = @left_paths
  self
end

#left_green ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 38

def left_green()
  @paths = [@left_green]
  self
end

#left_red ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 43

def left_red()
  @paths = [@left_red]
  self
end

#off ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 66

def off()
  self.on(0, 0)
end

#on(*args) ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 58

def on(*args)
  args = args.flatten
  args = [MAX_BRIGHTNESS, MAX_BRIGHTNESS] if args.empty?
  set_each_trigger_brightness(@paths, "none", args)

  @paths = @default_paths
end

#right ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 33

def right()
  @paths = @right_paths
  self
end

#right_green ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 48

def right_green()
  @paths = [@right_green]
  self
end

#right_red ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 53

def right_red()
  @paths = [@right_red]
  self
end

#set_flash(duration_time = 10) ⇒ Object 



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# File 'lib/ev3dev/led.rb', line 108

def set_flash(duration_time = 10)
  raise "couldn't specify the left/right green/red LED" if @paths.size != 1
  path = @paths[0]
  write_value_to_file(path, "brightness", 0)
  write_value_to_file(path, "trigger"   , "transient")
  write_value_with_check(path, "duration" , duration_time)
  write_value_with_check(path, "state"    , 1)

  @paths = @default_paths
end