class RubyHid::Device

The main interface for the Buzz controllers. Primarily used to monitor key pushes and trigger events. Keep a single instance of the class:

‘RubyHid::Device.new`

The ‘each` method exposes events directly as they come in

‘device.each { |event| puts event }`

The ‘start_watching` method starts a background job which runs the events bound to each button via the RubyHid::Button class. You can end this worker with `stop_watching`.

Constants

ALLOWED_EVENT_TYPES
AXIS_TYPE
BUTTON_TYPE

Event types we’re interested in, used to filter out meta-data.

1 - button (0, 1) 3 - axis (usually 0 - 255, centred on 128)

Event

Attributes

worker[RW]

The worker is a thread which is watching the device

Public Class Methods

list(search_term=nil) click to toggle source

List possible devices from /dev/input/by-id/

Or, list devices containing a string with search_term argument

# File lib/ruby_hid/device.rb, line 47
def Device.list(search_term=nil)
  if search_term
    Dir["/dev/input/by-id/*#{search_term}*event-joystick*"]
  else
    Dir['/dev/input/by-id/*event-joystick*']
  end
end
new(filename=nil, block_size=24) click to toggle source

Initialise device, getting event file from /dev/input/by-id/

# File lib/ruby_hid/device.rb, line 80
def initialize(filename=nil, block_size=24)
  raise NoFileSpecifiedError if filename.nil?
  @dev = File.open(filename)
  @block_size = block_size
rescue NoFileSpecifiedError, Errno::ENOENT => er
  puts "Could not find device: are your controllers plugged in?"
  raise er
end

Public Instance Methods

each() { |event| ... } click to toggle source

Expose each event to a block of code as it comes in.

# File lib/ruby_hid/device.rb, line 112
def each
  begin
    loop do
      event = read
      if event
        next unless ALLOWED_EVENT_TYPES.include?(event.type)
        yield event
      end
    end
  rescue Errno::ENODEV
  end
end
force_rights() click to toggle source
# File lib/ruby_hid/device.rb, line 37
def force_rights
  `sudo chmod 777 /sys/class/leds/*/brightness`
  `sudo chmod 777 /dev/input/event*`
end
format() click to toggle source

The format string which RubyHid uses to decode raw data.

# File lib/ruby_hid/device.rb, line 92
def format
  @format ||= case @block_size
                when 16
                  'llSSl'
                when 24
                  'qqSSl'
              end
end
read() click to toggle source

Read a single block.

# File lib/ruby_hid/device.rb, line 104
def read
  bin = @dev.read @block_size
  Event.new *bin.unpack(format)
end
start_watching() click to toggle source

Start a background worker which scans input file and triggers any events bound to each one.

# File lib/ruby_hid/device.rb, line 129
def start_watching
  return if @worker
  @worker = Thread.new do
    loop do
      event = read
      next unless ALLOWED_EVENT_TYPES.include?(event.type)
      case event.type
        when BUTTON_TYPE
          RubyHid::Button.trigger_event(event.code, event.value)
        when AXIS_TYPE
          RubyHid::Axis.trigger_event(event.code, event.value)
      end
    end
  end
end
stop_watching() click to toggle source

Stop the background worker, release it’s resources.

# File lib/ruby_hid/device.rb, line 148
def stop_watching
  @worker.kill
  @worker = nil
end