qr2gcode.rb

#
# QR2GCODE
# A QR Code to CNC (GRBL/GCODE) converter and generator
# January 2018 // Roman Mittermayr // mittermayr.com
#
# Enjoyed this? Drop me a Satoshi if you like:
# 1CJPbRRRAuxJ1m3SuR3u6NAntzrc5EP5py
#
#
# Note for really, ridiculously good programmers:
# This code is kept simple to make it easy to get a quick
# overview and allow for changes easily, by anyone.
# It could of course be optimised, severely.
#

require 'rqrcode'

# Settings
x_home = 10 #mm
y_home = 10 #mm
spacing = 1 #mm
feed_rate = 600
z_depth = -0.3 #mm
z_hover = 5 #mm
z_safe = 20 #mm
EOL = "\r\n"

vertical_refining = true
add_border = true

$gcode = ""

def add(code)
  $gcode += code + EOL
end

unless ARGV.count.eql? 1
  puts "\r\nSyntax: ruby qr2gcode.rb <string>\r\n\r\n"
  abort
end

data = ARGV.first
# TODO check for input validity

qr = RQRCode::QRCode.new(data, :level => :h)

#png = qr.as_png(file: "qrcode.png")

add("%")
add("(Header)")
add("(Generated by QR2GCode)")
add("(Header end.)")
add("G21") # units in mm
add("G00 G90 G80 G40 G49")
add("G1 Z#{z_safe} F#{feed_rate}")

x = 0
y = 0

is_drilling = false

# Create a clean QR matrix
matrix = []
qr.modules.each do |row|
    r = []
    row.each do |col|
      r << col
    end
    matrix.unshift(r) # reverse columns (0 origin is top/left on computer, but bottom/left on machine)
end
row_length = matrix[0].length

# Start with the horizontal paths
matrix.each do |row|
  row.each_with_index do |col, col_index|
    # Check if the next is also active, this means we can
    # leave the drill down, and carve a line
    is_next_active = false
    if col_index < (row_length-1)
      next_item = row[col_index+1]
      is_next_active = true if next_item
    end

    if col # active dot? Then drill!
      _x = x_home + x
      _y = y_home + y

      # Part 1: Move to the place we want to drill
      if is_drilling # Could be already drilling, don't go any lower then!!
        add("G1 X#{_x} Y#{_y}")
      else # Not drilling? Stay above ground while moving, until it's time to drill
        add("G1 X#{_x} Y#{_y} Z#{z_hover}")
      end
      # Okay, we're positioned - if we're not yet drilling, drill now.
      add("G1 Z#{z_depth} F#{feed_rate}") unless is_drilling
      is_drilling = true # Now we're definitely drilling
      unless is_next_active # If this was just a single dot, then lift the drill
        add("G1 Z#{z_hover} F#{feed_rate}")
        is_drilling = false
      end
    end
    x += spacing
  end

  # End of line: Lift up here, if drilling
  add("G1 Z#{z_hover} F#{feed_rate}") if is_drilling
  is_drilling = false
  y += spacing
  x = 0
end

# "Vertically-focused" QR matrix
if vertical_refining

  # All horizontal lines are done, let's transpose so we can go vertically now
  matrix = matrix.transpose

  # Return to start, then do the same but with vertifal refinements
  add("G1 Z#{z_safe} F#{feed_rate}")
  add("G00 X0 Y0")

  x = 0
  y = 0
  is_drilling = false

  matrix.each do |col|

    col.each_with_index do |row_item,row_index|
      # Only check whether or not we're part of a line if we are an active dot
      part_of_line = false
      is_next_active = false
      if row_item # is active dot?
        if row_index == 0 # First dot
          # Only check if next dot is active
          part_of_line = true if col[row_index+1]
          is_next_active = true
        elsif row_index == (row_length-1) # Last dot
          # Only check if previous dot is active
          part_of_line = true if col[row_index-1]
        else # Middle dot
          # Check if EITHER previous or next is active
          part_of_line = true if col[row_index-1]
          part_of_line = true if col[row_index+1]
          is_next_active = true if col[row_index+1]
        end
      end

      # If this is a 'single dot', then skip here
      # We are only refining lines, no point in working on that dot again
      if part_of_line
        _x = x_home + x
        _y = y_home + y
        if is_drilling # drilling already, keep on carvin'
          add("G1 X#{_x} Y#{_y}")
        else # Not drilling, so stay above ground until we're there
          add("G1 X#{_x} Y#{_y} Z#{z_hover}")
        end
        add("G1 Z#{z_depth} F#{feed_rate}") unless is_drilling
        is_drilling = true # Now we're definitely drilling
        unless is_next_active
          add("G1 Z#{z_hover} F#{feed_rate}") # Lift up, if we're done drilling
          is_drilling = false
        end
      end # part of a line?

      y += spacing
    end # end of column

    # Lift up here, if drilling
    add("G1 Z#{z_hover} F#{feed_rate}") if is_drilling
    is_drilling = false
    x += spacing # Move to next column
    y = 0 # Start back at the top
  end
end # of vertical_refining


if add_border
  padding = 5
  add("G1 X#{x_home-padding} Y#{y_home-padding} Z#{z_safe}")
  add("G1 Z#{z_depth}")
  add("G1 X#{x_home-padding} Y#{y_home+padding+(spacing*row_length)}")
  add("G1 X#{x_home+padding+(spacing*row_length)} Y#{y_home+padding+(spacing*row_length)}")
  add("G1 X#{x_home+padding+(spacing*row_length)} Y#{y_home-padding}")
  add("G1 X#{x_home-padding} Y#{y_home-padding}")
  add("G1 Z#{z_safe}")
end


add("G1 Z#{z_safe} F#{feed_rate}")
add("G00 X0 Y0")
add("M30")
add("%")

File.open("qrcode.ngc", "w") { |f| f.write($gcode) }