A script to export support items from KiCAD to JSON

Kicad-Keyboard-Support-Exporter.py

# Board Importer

# ABOUT
# The board has the following Edge Cuts:
# - Circles:  These are for support screws
# - Polygon:  This is the outside shape type


import pcbnew
import logging
import re
import pprint
from typing import Tuple, List

logger = logging.getLogger(__name__)

# Type alias
MM = int
X = MM
Y = MM
Width = MM
Height = MM
Rotation = int

# Board Dimensions
pcb_width = None
pcb_height = None
pcb_center_x = None
pcb_center_y = None

# Support Items to Generate
support_stems: List[Tuple[X, Y]] = []
switches: List[Tuple[X, Y]] = []
diodes: List[Tuple[X, Y, Rotation]] = []
smd_cutouts: List[Tuple[X, Y, Width, Height]] = []

board = pcbnew.GetBoard()

# Helper Functions
def ToFreecadCord(cord: pcbnew.VECTOR2I) -> Tuple[X, Y]:
	"""
	Converts the coordinate systems from KiCAD's internal measurement
	system to mm around origin, that FreeCAD will use
	"""
	x, y = tuple(pcbnew.pcbIUScale.IUTomm(i) for i in cord)
	x -= pcb_center_x
	y -= pcb_center_y
	return round(x, 2), -1 * round(y, 2)


# Populate the board dimensions
for drawing in board.GetDrawings():
	if not drawing.GetLayerName() == 'Edge.Cuts' or drawing.GetShape() != pcbnew.S_POLYGON:
		continue
	outline = drawing
	box = outline.GetBoundingBox()
	pcb_width = pcbnew.pcbIUScale.IUTomm(box.GetWidth())
	pcb_height = pcbnew.pcbIUScale.IUTomm(box.GetHeight())
	pcb_center = box.Centre()
	pcb_center_x = pcbnew.pcbIUScale.IUTomm(box.Centre()[0])
	pcb_center_y = pcbnew.pcbIUScale.IUTomm(box.Centre()[1])


# Generate the locations of the support stems, and the 
for drawing in board.GetDrawings():

	# We're only interested in Edge cuts
	if not drawing.GetLayerName() == 'Edge.Cuts' or drawing.GetShape() != pcbnew.S_CIRCLE:
		continue

	support_stems.append(ToFreecadCord(drawing.GetCenter()))


# Generate cutout positions for both switches, and any surface mount component we have
for footprint in board.GetFootprints():
	reference = footprint.GetReferenceAsString()
	location = ToFreecadCord(footprint.GetPosition())

	if re.fullmatch(r'S\d+', reference):
		# This is a switch
		switches.append(location)
	elif re.fullmatch(r'D\d+', reference):
		x, y = location
		diodes.append((x, y, footprint.GetOrientationDegrees()))

# SMD Component cutouts
for drawing in board.GetDrawings():
	if not drawing.GetLayerName() == 'User.4':
		continue

	x, y = ToFreecadCord(drawing.GetCenter())
	width = pcbnew.pcbIUScale.IUTomm(drawing.GetRectangleWidth())
	height = pcbnew.pcbIUScale.IUTomm(drawing.GetRectangleHeight())
	smd_cutouts.append((x, y, width, height))


# Update the grid origin
board.GetDesignSettings().SetGridOrigin(pcb_center)
pcbnew.Refresh()


print("Board Supports:\n\n")
print(json.dumps({
	"width": pcb_width,
	"height": pcb_height,
	"support_stems": support_stems,
	"switches": switches,
	"diodes": diodes,
	"smd_cutouts": smd_cutouts
}))