Module: BrotherEscp::Sequence

Defined in:
lib/brother_escp/sequence.rb

Overview

This module take care of the commands and various esc sequences to send meta data to the printer

Constant Summary collapse

SEQUENCES =

predefined sequence of commands for the printer

{

  # Printer hardware
  HW_INIT:                  [0x1b, 0x40], # Clear data in buffer and reset modes
  HW_SET_ESCP_MODE:         [0x1B, 0x69, 0x61, 0x00], # Sets the command mode to ESC/P

  # Select landscape orientation
  LANDSCAPE_ON:             [0x1b, 0x69, 0x4c, 1],
  LANDSCAPE_OFF:            [0x1b, 0x69, 0x4c, 0],

  # Line feed commands
  LINE_FEED:                [0x1b, 0x33],

  # Specify page length
  PAGE_LENGTH:              [0x1b, 0x28, 0x43, 2, 0],

  # Feed control sequences
  CTL_LF:                   [0x0a],                               # Print and line feed
  CTL_FF:                   [0x0c],                               # Form feed
  CTL_CR:                   [0x0d],                               # Carriage return
  CTL_HT:                   [0x09],                               # Horizontal tab
  CTL_VT:                   [0x0b],                               # Vertical tab
}.freeze

Class Method Summary collapse

Class Method Details

.crlf ⇒ Object

helper method to issue a carriage return / line feed sequence (go to the next line)



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# File 'lib/brother_escp/sequence.rb', line 41

def crlf
  sequence [0x0d, 0x0a]
end

.line_feed_size(n) ⇒ Object

Helper method to set the line feed size

Parameters:

  • n (Integer) —

    line feed size in dots



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# File 'lib/brother_escp/sequence.rb', line 47

def line_feed_size(n)
  sequence(:LINE_FEED) + sequence(n)
end

.page_length(n) ⇒ Object

Helper method to set the page length

Parameters:

  • n (Integer) —

    page length size in dots



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# File 'lib/brother_escp/sequence.rb', line 53

def page_length(n)
  sequence(:PAGE_LENGTH) + sequence([n % 256, n / 256])
end

.sequence(value) ⇒ Object

Format a sequence to the raw data needed by the printer

Parameters:

  • value (Symbol, Integer, Array) —

    Symbol will take the references from the SEQUENCES, Integer or Array will be packed as a simple ASCII string



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# File 'lib/brother_escp/sequence.rb', line 34

def sequence(value)
  val = value.is_a?(Symbol) ? SEQUENCES[value] : value

  Array(val).pack('C*')
end