Turtle G-Code

A small library for converting python turtle commands into G-Code for use with a pen-plotter.

Simply import this library instead of the default turtle one and then add a call to turtle.write_gcode() at the end to get the G-Code of the shapes you have drawn.

Things this library doesn't support:

• Stamps
• Writing Text
• Different colours/thicknesses of pen
• Undoing actions (undo functions throw an error if called)

Have fun :)

Basic Use

The module is designed to be pretty much a drop in replacement for the normal turtle library.

If (for example) you had this python code

import turtle

turtle.pendown()
turtle.forward(50)
turtle.circle(20)

you could convert it into G-Code by changing it to

import turtle_gcode as turtle

turtle.pendown()
turtle.forward(50)
turtle.circle(20)

turtle.write_gcode(100, 100)

More options

The turtle stores an internal buffer of all the moves made that would write to the output. They can then be output to a string.

There are two functions defined

write_gcode()

Writes the current move buffer as G-Code to the output. The drawing is automatically scaled to be as large as possible within the specified bounds. If allow_rotation is True then the drawing may also be rotated if that would allow it to be larger.

All parameters:

• width -- the width of the usable area of the plotter
• height -- the height of the usable area of the plotter
• x -- the x coordinate of the bottom left corner of the usable area of the plotter (default 0)
• y -- the y coordinate of the bottom left corner of the usable area of the plotter (default 0)
• allow_rotation -- if the drawing should be automatically rotated by 90deg if that will allow it to be drawn bigger in the supplied area (default False)
• circle_mode -- either 'radius' or 'centre', which circle drawing method the G-Code should use (default 'centre')
• penup_command -- the G-Code command to send the the plotter to move the pen up, by default no command is sent and the pen is assumed to always be down
• pendown_command -- the G-Code command to send the the plotter to move the pen down, by default no command is sent and the pen is assumed to always be down

clear_gcode()

Clears all the moves from the G-Code buffer.

License

Like the original turtle code this is under a zlib license.

A small part of the original turtle code is used, again under the original zlib license.