Class: SimpleRaspberryPi

Inherits:
Object
  • Object
show all
Defined in:
lib/simple_raspberrypi.rb

Defined Under Namespace

Classes: PinX, Void

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(x = []) ⇒ SimpleRaspberryPi

Returns a new instance of SimpleRaspberryPi.



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# File 'lib/simple_raspberrypi.rb', line 92

def initialize(x=[])
  
  RPi::GPIO.set_numbering :bcm  
  
  a = case x
  when Fixnum
    [x]
  when String
    [x]
  when Array
    x
  end

  unexport_all a
  
  @pins = a.map {|pin| PinX.new pin }
  
  def @pins.[](i)

    if i.to_i >= self.length then
      puts "RPi warning: PinX instance #{i.inspect} not found"
      Void.new
    else
      self.at(i)
    end 
  end    
  
  at_exit do
    
    # to avoid "Device or resource busy @ fptr_finalize - /sys/class/gpio/export"
    # we unexport the pins we used
    
    unexport_all a
  end    
end

Class Method Details

.[](i) ⇒ Object 



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# File 'lib/simple_raspberrypi.rb', line 109

def @pins.[](i)

  if i.to_i >= self.length then
    puts "RPi warning: PinX instance #{i.inspect} not found"
    Void.new
  else
    self.at(i)
  end 
end

.unexport(a) ⇒ Object 



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# File 'lib/simple_raspberrypi.rb', line 147

def self.unexport(a)
  a.each {|pin| File.write "/sys/class/gpio/unexport", pin }
end

Instance Method Details

#on_exit ⇒ Object 



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# File 'lib/simple_raspberrypi.rb', line 143

def on_exit
  unexport_all @pins
end

#pin ⇒ Object 



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# File 'lib/simple_raspberrypi.rb', line 128

def pin()   @pins.first  end

#pins ⇒ Object 



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# File 'lib/simple_raspberrypi.rb', line 129

def pins()  @pins        end

#unexport_all(pins) ⇒ Object 



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# File 'lib/simple_raspberrypi.rb', line 131

def unexport_all(pins)
  
  pins.each do |pin|
    
    next unless File.exists? '/sys/class/gpio/gpio' + pin.to_s

    File.write "/sys/class/gpio/unexport", pin

  end
  
end