Class: Artoo::Adaptors::IO::DigitalPin

Inherits:
Object
  • Object
show all
Defined in:
lib/artoo/adaptors/io/digital_pin.rb

Constant Summary collapse

GPIO_PATH = 
"/sys/class/gpio"
GPIO_DIRECTION_READ = 
"in"
GPIO_DIRECTION_WRITE = 
"out"
HIGH = 
1
LOW = 
0

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(pin_num, mode) ⇒ DigitalPin

Returns a new instance of DigitalPin.



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 13

def initialize(pin_num, mode)
  @pin_num = pin_num

  File.open("#{ GPIO_PATH }/export", "w") { |f| f.write("#{ pin_num }") }
  File.close
  # Sets the pin for read or write
  set_mode(mode)
end

Instance Attribute Details

#mode ⇒ Object (readonly)

Returns the value of attribute mode.



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 5

def mode
  @mode
end

#pin_file ⇒ Object (readonly)

Returns the value of attribute pin_file.



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 5

def pin_file
  @pin_file
end

#pin_num ⇒ Object (readonly)

Returns the value of attribute pin_num.



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 5

def pin_num
  @pin_num
end

#status ⇒ Object (readonly)

Returns the value of attribute status.



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 5

def status
  @status
end

Instance Method Details

#close ⇒ Object

Unexports the pin in GPIO to leave it free



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 86

def close
  off! if @mode == 'w'
  File.open("#{ GPIO_PATH }/unexport", "w") { |f| f.write("#{pin_num}") }
  File.close
  @pin_file.close
end

#digital_read ⇒ Object

Reads digitally from the specified pin on initialize



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 42

def digital_read
  set_mode('r') unless @mode == 'r'

  @pin_file.read
end

#digital_write(value) ⇒ Object

Writes to the specified pin Digitally accepts values :high or :low, 1 or 0, "1" or "0"

Raises:

  • (StandardError) 


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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 24

def digital_write(value)
  set_mode('w') unless @mode == 'w'

  if value.is_a? Symbol
    value = (value == :high) ? 1 : 0
  end

  value = value.to_i

  raise StandardError unless ([HIGH, LOW].include? value)

  @status = (value == 1) ? 'high' : 'low'

  @pin_file.write(value)
  @pin_file.flush
end

#off! ⇒ Object

Sets digital write for the pin to LOW



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 81

def off!
  digital_write(:off)
end

#off? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 71

def off?
  !self.on?
end

#on! ⇒ Object

Sets digital write for the pin to HIGH



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 76

def on!
  digital_write(:high)
end

#on? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 67

def on?
  (@status == 'high') ? true : false
end

#set_mode(mode) ⇒ Object

Sets the pin in GPIO for read or write.



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 49

def set_mode(mode)
  @mode = mode

  if mode == 'w'
    set_pin(mode: 'w', direction: GPIO_DIRECTION_WRITE)
  elsif mode =='r'
    set_pin(mode: 'r', direction: GPIO_DIRECTION_READ)
  end
end

#set_pin(settings) ⇒ Object 



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# File 'lib/artoo/adaptors/io/digital_pin.rb', line 59

def set_pin(settings)
  mode = settings[:mode]
  direction = settings[:direction]
  File.open("#{ GPIO_PATH }/gpio#{ pin_num }/direction", "w") { |f| f.write(direction) }
  File.close
  @pin_file = File.open("#{ GPIO_PATH }/gpio#{ pin_num }/value", mode)
end