A ruby implementation of ESC/POS (thermal) printer command specification.
Add this line to your application's Gemfile:
gem 'escpos'
# see https://github.com/escpos/escpos-image
gem 'escpos-image' # add this if you want to print images
And then execute:
$ bundle
Or install it yourself as:
$ gem install escpos
To keep this gem lightweight and modular image support was implemented in another gem:
https://github.com/escpos/escpos-image
# 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'
Or install it yourself as:
gem install escpos-image
# and then depending on your image processor of choice
gem install mini_magick
# or
gem install chunky_png
For more information about image processors, their options and supported formats please see https://github.com/escpos/escpos-image readme file.
@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
<% # my_report.erb: %>
<%= big "Order number #{order[:number]}" %>
<%= item "First item" %>
<%= item "Second item" %>
<%= item "Third item" %>
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
Method name | Description |
---|---|
text | Normal text formatting |
encoding, set_encoding, set_printer_encoding | Set printer encoding (see example below) |
encode | Encode text for the printer (see example below) |
double_height | Double height text |
quad_text, big, title, header, double_width_double_height, double_height_double_width | Double width & Double height text |
double_width | Double width text |
underline, u | Underlined text |
underline2, u2 | Stronger underlined text |
bold, b | Bold text |
left | Align to left |
right | Align to right |
center | Align to center |
invert, inverted | Color inverted text |
black, default_color, color_black, black_color | Default Color (Usually black) |
red, alt_color, alternative_color, color_red, red_color | Alternative Color (Usually Red) |
barcode | Print barcode (see example below) |
partial_cut | Partially cut the paper (may not be available on all devices) |
cut | Fully cut the paper (may not be available on all devices) |
To print diacritics (accented characters) with ESC/POS two things have to be done. First the desired code page must be set on the printer (can be done using an ESC/POS command) and the desired text has to be encoded to the code page set on the printer.
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")
- List of available code pages for
set_printer_encoding
: https://github.com/escpos/escpos/blob/master/lib/escpos.rb#L30 - Options for
encoding
inencode
helper: Anything listed inEncoding.constants
Some printers (e.g. Epson TM line) allow setting a default code page in printer setup, then the set_printer_encoding
call can be omitted.
The barcode helper accepts barcode data as first argument and an options hash as second.
Possible options:
Option | Possible values | Description |
---|---|---|
format | Escpos::BARCODE_UPC_A: Barcode type UPC-A Escpos::BARCODE_UPC_E: Barcode type UPC-E Escpos::BARCODE_EAN13: Barcode type EAN13 Escpos::BARCODE_EAN8: Barcode type EAN8 Escpos::BARCODE_CODE39: Barcode type CODE39 Escpos::BARCODE_ITF: Barcode type ITF Escpos::BARCODE_NW7: Barcode type NW7 |
Type of barcode |
text_position | Escpos::BARCODE_TXT_OFF: no text, only barcode Escpos::BARCODE_TXT_ABV: text positioned above the barcode Escpos::BARCODE_TXT_BLW: text positioned below the barcode Escpos::BARCODE_TXT_BTH: text positioned both above and below the barcode |
Text position |
height | 1 to 255 | Barcode height |
width | 2 to 6 | Barcode width |
barcode_data = Escpos::Helpers.barcode("12345678", {
format: Escpos::BARCODE_CODE39,
text_position: Escpos::BARCODE_TXT_BLW,
height: 50,
width: 3
})
Bug reports and pull requests are welcome on GitHub at https://github.com/escpos/escpos.
- Fork it ( https://github.com/escpos/escpos/fork )
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create a new Pull Request