Class: Denko::SPI::InputRegister

Inherits:
BaseRegister show all
Includes:
Behaviors::Lifecycle
Defined in:
lib/denko/spi/input_register.rb

Constant Summary

Constants included from Behaviors::Lifecycle

Behaviors::Lifecycle::CALLBACK_METHODS

Instance Attribute Summary

Attributes inherited from BaseRegister

#bytes

Attributes included from Peripheral

#spi_bit_order, #spi_frequency, #spi_mode

Attributes included from Behaviors::State

#state

Attributes included from Behaviors::Component

#board, #params

Attributes included from Behaviors::MultiPin

#pin, #pins, #proxies

Instance Method Summary collapse

Methods included from Behaviors::Lifecycle

included

Methods inherited from BaseRegister

#is_a_register?, #platform, #state

Methods included from Behaviors::BoardProxy

#analog_read_high, #analog_write_high, #convert_pin, #high, #low, #set_pin_mode, #start_read

Methods included from Behaviors::Subcomponents

#add_component, #add_hw_i2c, #add_hw_spi, #add_single_pin, #components, #hw_i2c_comps, #hw_spi_comps, #remove_component, #remove_hw_i2c, #remove_hw_spi, #remove_single_pin, #single_pin_components

Methods included from Peripheral

#ensure_byte_array, #initialize_pins, #proxy_pin, #spi_listen, #spi_read, #spi_stop, #spi_transfer, #spi_write

Methods included from Behaviors::Callbacks

#add_callback, #callbacks, #pre_callback_filter, #remove_callback

Methods included from Behaviors::State

#update_state

Methods included from Behaviors::BusPeripheral

#atomically

Methods included from Behaviors::Component

#initialize, #micro_delay

Methods included from Behaviors::MultiPin

#convert_pins, #proxy_pin, #proxy_states, #require_pin, #require_pins

Instance Method Details

#any_listening ⇒ Object 



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# File 'lib/denko/spi/input_register.rb', line 56

def any_listening
  listening_pins.each { |p| return true if p }
  false
end

#byte_array_to_bit_array(byte_array) ⇒ Object

Convert array of bytes coming from the register into an array of bits to update self state and give to component callbacks.



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# File 'lib/denko/spi/input_register.rb', line 120

def byte_array_to_bit_array(byte_array)
  #
  # For each array element (1 byte):
  # decimal number as string -> integer -> padded string of binary digits
  # -> reverse digits from reading order to array indexing order
  # -> join digits of all bytes into one string
  #
  binary_string = byte_array.map do |byte|
    byte.to_i.to_s(2).rjust(8, "0").reverse
  end.join

  # Split the digits out of the string into individual integers.
  binary_string.split("").map { |bit| bit.to_i }
end

#digital_listen(pin, divider) ⇒ Object 



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# File 'lib/denko/spi/input_register.rb', line 46

def digital_listen(pin, divider)
  listen unless any_listening
  listening_pins[pin] = true
end

#digital_read(pin) ⇒ Object

BoardProxy interface



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# File 'lib/denko/spi/input_register.rb', line 37

def digital_read(pin)
  # Remember what pin was read and force callbacks to run next update.
  add_callback(:force_update) { Proc.new{} }
  reading_pins[pin] = true

  # Don't actually call #read if already listening.
  read unless any_listening
end

#enable_proxy ⇒ Object

Mimic Board#update, but in a callback fired through #update. This doesn’t interfere with using the register directly, and doesn’t fire if the board isn’t acting as a proxy (no components).



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# File 'lib/denko/spi/input_register.rb', line 66

def enable_proxy
  self.add_callback(:board_proxy) do |bit_array|
    bit_array.each_with_index do |value, pin|
      components.each do |part|
        update_component(part, pin, value) if pin == part.pin
      end
      reading_pins[pin] = false
    end
  end
end

#listen ⇒ Object 



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# File 'lib/denko/spi/input_register.rb', line 26

def listen
  spi_listen(bytes)
end

#listening_pins ⇒ Object 



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# File 'lib/denko/spi/input_register.rb', line 14

def listening_pins
  @listening_pins ||= Array.new(bytes*8) { false }
end

#read ⇒ Object 



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# File 'lib/denko/spi/input_register.rb', line 22

def read
  spi_read(bytes)
end

#reading_pins ⇒ Object

Keep track of whether anything is listening or reading a specific pin. This might be separate from whether a component is attached or not.



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# File 'lib/denko/spi/input_register.rb', line 10

def reading_pins
  @reading_pins ||= Array.new(bytes*8) { false }
end

#stop ⇒ Object 



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# File 'lib/denko/spi/input_register.rb', line 30

def stop
  spi_stop
end

#stop_listener(pin) ⇒ Object 



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# File 'lib/denko/spi/input_register.rb', line 51

def stop_listener(pin)
  listening_pins[pin] = false
  stop unless any_listening
end

#update(message) ⇒ Object

Override Callbacks#update to make sure we handle :force_update within the main mutex lock.



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# File 'lib/denko/spi/input_register.rb', line 81

def update(message)
  # Since overriding update, make sure this is a byte array first.
  byte_array = ensure_byte_array(message)

  bits = byte_array_to_bit_array(byte_array)

  @callback_mutex.lock
  if @callbacks && !@callbacks.empty?
    # Arduino doesn't de-duplicate state. Do it, but honor :force_update callbacks.
    if (bits != state) || @callbacks[:force_update]
      @callbacks.each_value do |array|
        array.each { |callback| callback.call(bits) }
      end
    end

    # Remove both :read and :force update while inside the lock.
    @callbacks.delete(:read)
    @callbacks.delete(:force_update)
  end
  @callback_mutex.unlock

  self.state = bits
end

#update_component(part, pin, value) ⇒ Object 



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# File 'lib/denko/spi/input_register.rb', line 105

def update_component(part, pin, value)
  # Update if component is listening and value has changed.
  if listening_pins[pin] && (value != state[pin])
    part.update(value)
  # Also update if the component forced a read.
  # Always called inside @callback_mutex, so @callbacks, not callbacks
  elsif reading_pins[pin] && @callbacks[:force_update]
    part.update(value)
  end
end