pygcode

GCODE Parser for Python

Currently in development, this is planned to be a pythonic interpreter and encoder for g-code. I'll be learning along the way, but the plan is to follow the lead of GRBL.

Installation

pip install pygcode

Usage

Just brainstorming here...

import pygcode
import math
import euclid

gfile_in = pygcode.Parser('part.gcode')
gfile_out = pygcode.Writer('part2.gcode')

total_travel = 0
total_time = 0

for (state, block) in gfile_in.iterstate():
    # where:
    #   state = CNC's state before the block is executed
    #   block = the gcode to be executed next

    # validation
    if isinstance(block, pygcode.GCodeArc):
        error = block.r2 - block.r1
        if error > 0.0005:
            raise pygcode.GCodeValidationError("arc points are not on the same circle")
            #block.set_precision(0.0005, method=pygcode.GCodeArc.EFFECT_ENDPOINT)
            block.set_precision(0.0005, method=pygcode.GCodeArc.EFFECT_RADIUS)

    # random metrics
    travel_vector = block.position - state.position # euclid.Vector3 instance
    distance = travel_vector.magnitude()
    travel = block.travel_distance(position=state.position) # eg: distance != travel for G02 & G03

    total_travel += travel
    #total_time += block.time(feed_rate=state.feed_rate) # doesn't consider the feedrate being changed in this block
    total_time += block.time(state=state)

    # rotate : entire file 90deg CCW
    block.rotate(euclid.Quaternion.new_rotate_axis(
        math.pi / 2, euclid.Vector3(0, 0, 1)
    ))
    # translate : entire file x += 1, y += 2 mm (after rotation)
    block.translate(euclid.Vector3(1, 2, 0), unit=pygcode.UNIT_MM)

    # TODO: then do something like write it to another file
    gfile_out.write(block)

gfile_in.close()
gfile_out.close()

Supported G-Codes

GCode support is planned to follow that of GRBL.

But anything pre v1.0 will be a sub-set, focusing on the issues I'm having... I'm selfish that way.

TBD: list of gcodes (also as a TODO list)