gem 'escpos'

# see https://github.com/escpos/escpos-image
gem 'escpos-image' # add this if you want to print images

# Add this line to your application's Gemfile if you want to print images
gem 'escpos-image'
# And depending on your image processor of choice
gem 'mini_magick'
# or
gem 'chunky_png'

@printer = Escpos::Printer.new
@printer << "Some text"
@printer << Escpos::Helpers.big "Big text"

@printer.to_escpos # returns ESC/POS data ready to be sent to printer
# on linux this can be piped directly to /dev/usb/lp0
# with network printer sent directly to printer socket (see example below)
# with serial port printer it can be sent directly to the serial port

@printer.to_base64 # returns base64 encoded ESC/POS data

# my_report.rb:

class MyReport < Escpos::Report
  def item(text)
    @count ||= 0
    @count += 1
    bold "#{@count}. #{text}"
  end

  def order
    options[:order]
  end
end

report = MyReport.new 'path/to/my_report.erb', {
  order: { number: 123 }
}
@printer << report.render
@printer.cut!

@printer.to_escpos # returns ESC/POS data ready to be sent to printer
# - on linux this can be piped directly to /dev/usb/lp0
# - with network printer sent directly to printer socket
# - with serial port printer it can be sent directly to the serial port
# see example below

@printer.to_base64 # returns base64 encoded ESC/POS data

printer = Escpos::Printer.new
printer << "Some text"

# change /dev/usb/lp0 to match the printer device
# e.g. on Linux this may be /dev/ttyS0 for serial port
File.open("/dev/usb/lp0", "w") { |f| f.write printer.to_escpos }

require "socket"

printer = Escpos::Printer.new
printer << "Some text"

# change 192.168.2.7 and 9100 to match the IP or host and port of the printer
socket = TCPSocket.new "192.168.2.7", 9100

socket.write printer.to_escpos
socket.close

printer = Escpos::Printer.new
printer << Escpos::Helpers.set_printer_encoding(Escpos::CP_ISO8859_2)
printer << Escpos::Helpers.encode("This is UTF-8 to ISO-8859-2 text: ěščřžýáíéúů", encoding: "ISO-8859-2")

barcode_data = Escpos::Helpers.barcode("12345678", {
  format: Escpos::BARCODE_CODE39,
  text_position: Escpos::BARCODE_TXT_BLW,
  height: 50,
  width: 3
})