#!/usr/bin/env python3
import subprocess
import sys
import math
import multiprocessing
import os
from math import *
from pathlib import Path
from itertools import cycle
from contextlib import contextmanager
from scipy.constants import mu_0
import numpy as np
import click
import matplotlib as mpl
from gerbonara.cad.kicad import pcb as kicad_pcb
from gerbonara.cad.kicad import footprints as kicad_fp
from gerbonara.cad.kicad import graphical_primitives as kicad_gr
from gerbonara.cad.kicad import primitives as kicad_pr
from gerbonara.utils import Tag
from gerbonara import graphic_primitives as gp
from gerbonara import graphic_objects as go
__version__ = '1.0.0'
def point_line_distance(p, l1, l2):
x0, y0 = p
x1, y1 = l1
x2, y2 = l2
# https://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line
return abs((x2-x1)*(y1-y0) - (x1-x0)*(y2-y1)) / sqrt((x2-x1)**2 + (y2-y1)**2)
def line_line_intersection(l1, l2):
p1, p2 = l1
p3, p4 = l2
x1, y1 = p1
x2, y2 = p2
x3, y3 = p3
x4, y4 = p4
# https://en.wikipedia.org/wiki/Line%E2%80%93line_intersection
px = ((x1*y2-y1*x2)*(x3-x4)-(x1-x2)*(x3*y4-y3*x4))/((x1-x2)*(y3-y4)-(y1-y2)*(x3-x4))
py = ((x1*y2-y1*x2)*(y3-y4)-(y1-y2)*(x3*y4-y3*x4))/((x1-x2)*(y3-y4)-(y1-y2)*(x3-x4))
return px, py
def angle_between_vectors(va, vb):
angle = atan2(vb[1], vb[0]) - atan2(va[1], va[0])
if angle < 0:
angle += 2*pi
return angle
def traces_to_gmsh(traces, mesh_out, bbox, model_name='gerbonara_board', log=True, copper_thickness=0.035, board_thickness=0.8, air_box_margin=5.0):
import gmsh
occ = gmsh.model.occ
eps = 1e-6
gmsh.initialize()
gmsh.model.add('gerbonara_board')
if log:
gmsh.logger.start()
trace_tags = {}
trace_ends = set()
render_cache = {}
for i, tr in enumerate(traces, start=1):
layer = tr[1].layer
z0 = 0 if layer == 'F.Cu' else -(board_thickness+copper_thickness)
prims = [prim
for elem in tr
for obj in elem.render(cache=render_cache)
for prim in obj.to_primitives()]
tags = []
for prim in prims:
if isinstance(prim, gp.Line):
length = dist((prim.x1, prim.y1), (prim.x2, prim.y2))
box_tag = occ.addBox(0, -prim.width/2, 0, length, prim.width, copper_thickness)
angle = atan2(prim.y2 - prim.y1, prim.x2 - prim.x1)
occ.rotate([(3, box_tag)], 0, 0, 0, 0, 0, 1, angle)
occ.translate([(3, box_tag)], prim.x1, prim.y1, z0)
tags.append(box_tag)
for x, y in ((prim.x1, prim.y1), (prim.x2, prim.y2)):
disc_id = (round(x, 3), round(y, 3), round(z0, 3), round(prim.width, 3))
if disc_id in trace_ends:
continue
trace_ends.add(disc_id)
cylinder_tag = occ.addCylinder(x, y, z0, 0, 0, copper_thickness, prim.width/2)
tags.append(cylinder_tag)
print('fusing', tags)
tags, tag_map = occ.fuse([(3, tags[0])], [(3, tag) for tag in tags[1:]])
print(tags)
assert len(tags) == 1
(_dim, tag), = tags
trace_tags[i] = tag
(x1, y1), (x2, y2) = bbox
substrate = occ.addBox(x1, y1, -board_thickness, x2-x1, y2-y1, board_thickness)
x1, y1 = x1-air_box_margin, y1-air_box_margin
x2, y2 = x2+air_box_margin, y2+air_box_margin
w, d = x2-x1, y2-y1
z0 = -board_thickness-air_box_margin
ab_h = board_thickness + 2*air_box_margin
airbox = occ.addBox(x1, y1, z0, w, d, ab_h)
print('Cutting airbox')
occ.cut([(3, airbox)], [(3, tag) for tag in trace_tags.values()], removeObject=True, removeTool=False)
print('Fragmenting')
fragment_tags, fragment_hierarchy = occ.fragment([(3, airbox)], [(3, substrate)] + [(3, tag) for tag in trace_tags.values()])
print('Synchronizing')
occ.synchronize()
substrate_physical = gmsh.model.add_physical_group(3, [substrate], name='substrate')
airbox_physical = gmsh.model.add_physical_group(3, [airbox], name='airbox')
trace_physical_surfaces = [
gmsh.model.add_physical_group(2, list(gmsh.model.getAdjacencies(3, tag)[1]), name=f'trace{i}')
for i, tag in trace_tags.items()]
airbox_adjacent = set(gmsh.model.getAdjacencies(3, airbox)[1])
in_bbox = {tag for _dim, tag in gmsh.model.getEntitiesInBoundingBox(x1+eps, y1+eps, z0+eps, x1+w-eps, y1+d-eps, z0+ab_h-eps, dim=3)}
airbox_physical_surface = gmsh.model.add_physical_group(2, list(airbox_adjacent - in_bbox), name='airbox_surface')
points_airbox_adjacent = set(gmsh.model.getAdjacencies(0, airbox)[1])
points_inside = {tag for _dim, tag in gmsh.model.getEntitiesInBoundingBox(x1+eps, y1+eps, z0+eps, x1+w-eps, y1+d-eps, z0+ab_h-eps, dim=0)}
gmsh.model.mesh.setSize([(0, tag) for tag in points_airbox_adjacent - points_inside], 10e-3)
#gmsh.option.setNumber('Mesh.MeshSizeFromCurvature', 90)
gmsh.option.setNumber('Mesh.Smoothing', 10)
gmsh.option.setNumber('Mesh.Algorithm3D', 10)
gmsh.option.setNumber('Mesh.MeshSizeMax', 1)
gmsh.option.setNumber('General.NumThreads', multiprocessing.cpu_count())
print('Meshing')
gmsh.model.mesh.generate(dim=3)
print('Writing')
gmsh.write(str(mesh_out))
@contextmanager
def model_delta():
import gmsh
gmsh.model.occ.synchronize()
entities = {i: set() for i in range(4)}
for dim, tag in gmsh.model.getEntities():
entities[dim].add(tag)
yield
gmsh.model.occ.synchronize()
new_entities = {i: set() for i in range(4)}
for dim, tag in gmsh.model.getEntities():
new_entities[dim].add(tag)
for i, dimtype in enumerate(['points', 'lines', 'surfaces', 'volumes']):
delta = entities[i] - new_entities[i]
print(f'Removed {dimtype} [{len(delta)}]: {", ".join(map(str, delta))[:180]}')
delta = new_entities[i] - entities[i]
print(f'New {dimtype} [{len(delta)}]: {", ".join(map(str, delta))[:180]}')
def _gmsh_coil_inductance_geometry(traces, mesh_out, bbox, copper_thickness, board_thickness, air_box_margin_h):
import gmsh
occ = gmsh.model.occ
trace_tags = []
trace_ends = set()
render_cache = {}
first_disk, last_disk = None, None
for i, tr in enumerate(traces, start=1):
layer = tr[1].layer
z0 = 0 if layer == 'F.Cu' else -(board_thickness+copper_thickness)
objs = [obj
for elem in tr
for obj in elem.render(cache=render_cache)]
tags = []
for ob in objs:
if isinstance(ob, go.Line):
length = dist((ob.x1, ob.y1), (ob.x2, ob.y2))
w = ob.aperture.equivalent_width('mm')
box_tag = occ.addBox(0, -w/2, 0, length, w, copper_thickness)
angle = atan2(ob.y2 - ob.y1, ob.x2 - ob.x1)
occ.rotate([(3, box_tag)], 0, 0, 0, 0, 0, 1, angle)
occ.translate([(3, box_tag)], ob.x1, ob.y1, z0)
tags.append(box_tag)
for x, y in ((ob.x1, ob.y1), (ob.x2, ob.y2)):
disc_id = (round(x, 3), round(y, 3), round(z0, 3), round(w, 3))
if disc_id in trace_ends:
continue
trace_ends.add(disc_id)
cylinder_tag = occ.addCylinder(x, y, z0, 0, 0, copper_thickness, w/2)
tags.append(cylinder_tag)
if first_disk is None:
occ.synchronize()
adjacent = gmsh.model.getAdjacencies(3, cylinder_tag)
first_disk = adjacent
elif i == len(traces) and last_disk is None:
occ.synchronize()
adjacent = gmsh.model.getAdjacencies(3, cylinder_tag)
last_disk = adjacent
for elem in tr:
if isinstance(elem, kicad_pcb.Via):
cylinder_tag = occ.addCylinder(elem.at.x, elem.at.y, 0, 0, 0, -board_thickness, elem.drill)
tags.append(cylinder_tag)
occ.synchronize()
print('fusing', tags)
tags, tag_map = occ.fuse([(3, tags[0])], [(3, tag) for tag in tags[1:]])
print(tags)
assert len(tags) == 1
(_dim, tag), = tags
trace_tags.append(tag)
print('fusing top-level', trace_tags)
tags, tag_map = occ.fuse([(3, trace_tags[0])], [(3, tag) for tag in trace_tags[1:]])
print(tags)
assert len(tags) == 1
(_dim, toplevel_tag), = tags
(x1, y1), (x2, y2) = bbox
first_geom = traces[0][0]
with model_delta():
print('Fragmenting disks')
interface_tag_top = occ.addDisk(first_geom.start.x, first_geom.start.y, 0, first_geom.width/2, first_geom.width/2)
interface_tag_bottom = occ.addDisk(first_geom.start.x, first_geom.start.y, -board_thickness, first_geom.width/2, first_geom.width/2)
occ.fragment([(3, toplevel_tag)], [(2, interface_tag_top), (2, interface_tag_bottom)], removeObject=True, removeTool=True)
substrate = occ.addBox(x1, y1, -board_thickness, x2-x1, y2-y1, board_thickness)
print('cut')
with model_delta():
print(occ.cut([(3, substrate)], [(3, toplevel_tag)], removeObject=True, removeTool=False))
return toplevel_tag, interface_tag_top, interface_tag_bottom, substrate
def traces_to_gmsh_mag(traces, mesh_out, bbox, model_name='gerbonara_board', log=True, copper_thickness=0.035, board_thickness=0.8, air_box_margin_h=30.0, air_box_margin_v=80.0):
import gmsh
occ = gmsh.model.occ
eps = 1e-6
gmsh.initialize()
gmsh.model.add('gerbonara_board')
if log:
gmsh.logger.start()
toplevel_tag, interface_tag_top, interface_tag_bottom, substrate = _gmsh_coil_inductance_geometry(traces, mesh_out, bbox, copper_thickness, board_thickness, air_box_margin_h)
(x1, y1), (x2, y2) = bbox
x1, y1 = x1-air_box_margin_h, y1-air_box_margin_h
x2, y2 = x2+air_box_margin_h, y2+air_box_margin_h
w, d = x2-x1, y2-y1
z0 = -2*copper_thickness-board_thickness-air_box_margin_v
ab_h = 2*copper_thickness + board_thickness + 2*air_box_margin_v
airbox = occ.addBox(x1, y1, z0, w, d, ab_h)
print('cut')
with model_delta():
print(occ.cut([(3, airbox)], [(3, toplevel_tag), (3, substrate)], removeObject=True, removeTool=False))
print(f'Fragmenting airbox ({airbox}) with {toplevel_tag=} {substrate=}')
with model_delta():
print(occ.fragment([(3, airbox)], [(3, toplevel_tag), (3, substrate)], removeObject=True, removeTool=False))
print('Synchronizing')
occ.synchronize()
first_geom = traces[0][0]
pcx, pcy = first_geom.start.x, first_geom.start.y
pcr = first_geom.width/2
(_dim, plane_top), = gmsh.model.getEntitiesInBoundingBox(pcx-pcr-eps, pcy-pcr-eps, -eps, pcx+pcr+eps, pcy+pcr+eps, eps, 2)
(_dim, plane_bottom), = gmsh.model.getEntitiesInBoundingBox(pcx-pcr-eps, pcy-pcr-eps, -board_thickness-eps, pcx+pcr+eps, pcy+pcr+eps, -board_thickness+eps, 2)
substrate_physical = gmsh.model.add_physical_group(3, [substrate], name='substrate')
airbox_physical = gmsh.model.add_physical_group(3, [airbox], name='airbox')
trace_physical = gmsh.model.add_physical_group(3, [toplevel_tag], name='trace')
gmsh.model.mesh.setSize([(0, tag) for dim, tag in gmsh.model.getBoundary([(3, toplevel_tag)], recursive=True) if dim == 0], 0.300)
#interface_tags_top = gmsh.model.getBoundary([(3, contact_tag_top)], oriented=False)
#interface_tags_bottom = gmsh.model.getBoundary([(3, contact_tag_bottom)], oriented=False)
interface_top_physical = gmsh.model.add_physical_group(2, [plane_top], name='interface_top')
interface_bottom_physical = gmsh.model.add_physical_group(2, [plane_bottom], name='interface_bottom')
airbox_adjacent = set(gmsh.model.getAdjacencies(3, airbox)[1])
in_bbox = {tag for _dim, tag in gmsh.model.getEntitiesInBoundingBox(x1+eps, y1+eps, z0+eps, x2-eps, y2-eps, z0+ab_h-eps, dim=2)}
airbox_physical_surface = gmsh.model.add_physical_group(2, list(airbox_adjacent - in_bbox), name='airbox_surface')
points_airbox_adjacent = {tag for _dim, tag in gmsh.model.getBoundary([(3, airbox)], recursive=True, oriented=False)}
print(f'{points_airbox_adjacent=}')
points_inside = {tag for _dim, tag in gmsh.model.getEntitiesInBoundingBox(x1+eps, y1+eps, z0+eps, x1+w-eps, y1+d-eps, z0+ab_h-eps, dim=0)}
#gmsh.model.mesh.setSize([(0, tag) for tag in points_airbox_adjacent - points_inside], 300e-3)
gmsh.option.setNumber('Mesh.MeshSizeFromCurvature', 32)
gmsh.option.setNumber('Mesh.Smoothing', 10)
gmsh.option.setNumber('Mesh.Algorithm3D', 10)
gmsh.option.setNumber('Mesh.MeshSizeMax', 10)
gmsh.option.setNumber('Mesh.MeshSizeMin', 0.08)
gmsh.option.setNumber('General.NumThreads', multiprocessing.cpu_count())
print('Meshing')
gmsh.model.mesh.generate(dim=3)
print('Writing to', str(mesh_out))
gmsh.write(str(mesh_out))
def traces_to_gmsh_mag_mutual(traces, mesh_out, bbox, model_name='gerbonara_board', log=True, copper_thickness=0.035, board_thickness=0.8, air_box_margin_h=30.0, air_box_margin_v=80.0, mutual_offset=(0, 0, 5), mutual_rotation=(0, 0, 0)):
import gmsh
occ = gmsh.model.occ
eps = 1e-6
gmsh.initialize()
gmsh.model.add('gerbonara_board')
if log:
gmsh.logger.start()
m_dx, m_dy, m_dz = mutual_offset
m_ax, m_ay, m_az = mutual_rotation
m_dz += 2*copper_thickness + board_thickness
toplevel_tag1, interface_tag_top1, interface_tag_bottom1, substrate1 = _gmsh_coil_inductance_geometry(traces, mesh_out, bbox, copper_thickness, board_thickness, air_box_margin_h)
upper_coil = [(3, toplevel_tag1), (3, substrate1)]
occ.translate(upper_coil, m_dx, m_dy, m_dz)
print('rotate')
with model_delta():
occ.rotate(upper_coil, 0, 0, 0, 0, 0, 1, m_az)
toplevel_tag2, interface_tag_top2, interface_tag_bottom2, substrate2 = _gmsh_coil_inductance_geometry(traces, mesh_out, bbox, copper_thickness, board_thickness, air_box_margin_h)
(x1, y1), (x2, y2) = bbox
x1, y1 = x1-air_box_margin_h, y1-air_box_margin_h
x2, y2 = x2+air_box_margin_h, y2+air_box_margin_h
w, d = x2-x1, y2-y1
z0 = -2*copper_thickness-board_thickness-air_box_margin_v
ab_h = 4*copper_thickness + 2*board_thickness + 2*air_box_margin_v + m_dz
airbox = occ.addBox(x1, y1, z0, w, d, ab_h)
print('cut')
with model_delta():
print(occ.cut([(3, airbox)], [(3, toplevel_tag1), (3, toplevel_tag2), (3, substrate1), (3, substrate2)], removeObject=True, removeTool=False))
print(f'Fragmenting airbox ({airbox}) with {toplevel_tag1=} {substrate1=} {toplevel_tag2=} {substrate2=}')
with model_delta():
print(occ.fragment([(3, airbox)], [(3, toplevel_tag1), (3, toplevel_tag2), (3, substrate1), (3, substrate2)], removeObject=True, removeTool=False))
print('Synchronizing')
occ.synchronize()
first_geom = traces[0][0]
pcx, pcy = first_geom.start.x + m_dx, first_geom.start.y + m_dy
pcx, pcy = math.cos(m_az) * pcx - math.sin(m_az) * pcy, math.sin(m_az) * pcx + math.cos(m_az) * pcy
pcr = first_geom.width/2
(_dim, plane_top1), = gmsh.model.getEntitiesInBoundingBox(pcx-pcr-eps, pcy-pcr-eps, m_dz-eps, pcx+pcr+eps, pcy+pcr+eps, m_dz+eps, 2)
(_dim, plane_bottom1), = gmsh.model.getEntitiesInBoundingBox(pcx-pcr-eps, pcy-pcr-eps, m_dz-board_thickness-eps, pcx+pcr+eps, pcy+pcr+eps, m_dz-board_thickness+eps, 2)
pcx, pcy = first_geom.start.x, first_geom.start.y
(_dim, plane_top2), = gmsh.model.getEntitiesInBoundingBox(pcx-pcr-eps, pcy-pcr-eps, -eps, pcx+pcr+eps, pcy+pcr+eps, eps, 2)
(_dim, plane_bottom2), = gmsh.model.getEntitiesInBoundingBox(pcx-pcr-eps, pcy-pcr-eps, -board_thickness-eps, pcx+pcr+eps, pcy+pcr+eps, -board_thickness+eps, 2)
substrate1_physical = gmsh.model.add_physical_group(3, [substrate1], name='substrate1')
trace1_physical = gmsh.model.add_physical_group(3, [toplevel_tag1], name='trace1')
substrate2_physical = gmsh.model.add_physical_group(3, [substrate2], name='substrate2')
trace2_physical = gmsh.model.add_physical_group(3, [toplevel_tag2], name='trace2')
airbox_physical = gmsh.model.add_physical_group(3, [airbox], name='airbox')
interface_top1_physical = gmsh.model.add_physical_group(2, [plane_top1], name='interface_top1')
interface_bottom1_physical = gmsh.model.add_physical_group(2, [plane_bottom1], name='interface_bottom1')
interface_top2_physical = gmsh.model.add_physical_group(2, [plane_top2], name='interface_top2')
interface_bottom2_physical = gmsh.model.add_physical_group(2, [plane_bottom2], name='interface_bottom2')
airbox_adjacent = set(gmsh.model.getAdjacencies(3, airbox)[1])
in_bbox = {tag for _dim, tag in gmsh.model.getEntitiesInBoundingBox(x1+eps, y1+eps, z0+eps, x2-eps, y2-eps, z0+ab_h-eps, dim=2)}
airbox_physical_surface = gmsh.model.add_physical_group(2, list(airbox_adjacent - in_bbox), name='airbox_surface')
points_airbox_adjacent = {tag for _dim, tag in gmsh.model.getBoundary([(3, airbox)], recursive=True, oriented=False)}
print(f'{points_airbox_adjacent=}')
points_inside = {tag for _dim, tag in gmsh.model.getEntitiesInBoundingBox(x1+eps, y1+eps, z0+eps, x1+w-eps, y1+d-eps, z0+ab_h-eps, dim=0)}
#gmsh.model.mesh.setSize([(0, tag) for tag in points_airbox_adjacent - points_inside], 300e-3)
gmsh.option.setNumber('Mesh.MeshSizeFromCurvature', 32)
gmsh.option.setNumber('Mesh.Smoothing', 10)
gmsh.option.setNumber('Mesh.Algorithm3D', 10)
gmsh.option.setNumber('Mesh.MeshSizeMax', 10)
gmsh.option.setNumber('Mesh.MeshSizeMin', 0.08)
gmsh.option.setNumber('General.NumThreads', multiprocessing.cpu_count())
print('Meshing')
gmsh.model.mesh.generate(dim=3)
print('Writing to', str(mesh_out))
gmsh.write(str(mesh_out))
def traces_to_magneticalc(traces, out, pcb_thickness=0.8):
coords = []
last_x, last_y, last_z = None, None, None
def coord(x, y, z):
nonlocal coords, last_x, last_y, last_z
if (x, y, z) != (last_x, last_y, last_z):
coords.append((x, y, z))
render_cache = {}
for tr in traces:
z = pcb_thickness if tr[1].layer == 'F.Cu' else 0
objs = [obj
for elem in tr
for obj in elem.render(cache=render_cache)
if isinstance(elem, (kicad_pcb.TrackSegment, kicad_pcb.TrackArc))]
# start / switch layer
coord(objs[0].x1, objs[0].y1, z)
for ob in objs:
coord(ob.x2, ob.y2, z)
np.savetxt(out, np.array(coords) / 10) # magneticalc expects centimeters, not millimeters.
class SVGPath:
def __init__(self, **attrs):
self.d = ''
self.attrs = attrs
def line(self, x, y):
self.d += f'L {x} {y} '
def move(self, x, y):
self.d += f'M {x} {y} '
def arc(self, x, y, r, large, sweep):
self.d += f'A {r} {r} 0 {int(large)} {int(sweep)} {x} {y} '
def close(self):
self.d += 'Z '
def __str__(self):
attrs = ' '.join(f'{key.replace("_", "-")}="{value}"' for key, value in self.attrs.items())
return f''
class SVGCircle:
def __init__(self, r, cx, cy, **attrs):
self.r = r
self.cx, self.cy = cx, cy
self.attrs = attrs
def __str__(self):
attrs = ' '.join(f'{key.replace("_", "-")}="{value}"' for key, value in self.attrs.items())
return f''
def svg_file(fn, stuff, vbw, vbh, vbx=0, vby=0):
with open(fn, 'w') as f:
f.write('\n')
f.write('\n')
f.write(f'\n')
# https://en.wikipedia.org/wiki/Farey_sequence#Next_term
def farey_sequence(n: int, descending: bool = False) -> None:
"""Print the n'th Farey sequence. Allow for either ascending or descending."""
a, b, c, d = 0, 1, 1, n
if descending:
a, c = 1, n - 1
#print(f"{a}/{b}")
yield a, b
while c <= n and not descending or a > 0 and descending:
k = (n + b) // d
a, b, c, d = c, d, k * c - a, k * d - b
#print(f"{a}/{b}")
yield a, b
def divisors(n, max_b=10):
for a, b in farey_sequence(n):
if a == n and b < max_b:
yield b
if b == n and a < max_b:
yield a
def print_valid_twists(ctx, param, value):
if not value or ctx.resilient_parsing:
return
print(f'Valid twist counts for {value} turns:', file=sys.stderr)
for d in divisors(value, value):
print(f' {d}', file=sys.stderr)
click.echo()
ctx.exit()
@click.command()
@click.argument('outfile', required=False, type=click.Path(writable=True, dir_okay=False, path_type=Path))
@click.option('--footprint-name', help="Name for the generated footprint. Default: Output file name sans extension.")
@click.option('--layer-pair', default='F.Cu,B.Cu', help="Target KiCad layer pair for the generated footprint, comma-separated. Default: F.Cu/B.Cu.")
@click.option('--turns', type=int, default=5, help='Number of turns')
@click.option('--pcb/--footprint', default=False, help='Generate a KiCad PCB instead of a footprint')
@click.option('--outer-diameter', type=float, default=50, help='Outer diameter [mm]')
@click.option('--inner-diameter', type=float, default=25, help='Inner diameter [mm]')
@click.option('--trace-width', type=float, default=None)
@click.option('--via-diameter', type=float, default=0.6)
@click.option('--two-layer/--single-layer', default=True)
@click.option('--via-drill', type=float, default=0.3)
@click.option('--via-offset', type=float, default=None, help='Radially offset vias from trace endpoints [mm]')
@click.option('--keepout-zone/--no-keepout-zone', default=True, help='Add a keepout are to the footprint (default: yes)')
@click.option('--keepout-margin', type=float, default=5, help='Margin between outside of coil and keepout area (mm, default: 5)')
@click.option('--copper-thickness', type=float, default=0.035, help='Copper thickness for resistance calculation and mesh generation in mm. Default: 0.035mm ^= 1 Oz')
@click.option('--board-thickness', type=float, default=1.53, help='Board substrate thickness for mesh generation in mm. Default: 1.53mm')
@click.option('--twists', type=int, default=1, help='Number of twists per revolution. Note that this number must be co-prime to the number of turns. Run with --show-twists to list valid values. (default: 1)')
@click.option('--circle-segments', type=int, default=64, help='When not using arcs, the number of points to use for arc interpolation per 360 degrees.')
@click.option('--show-twists', callback=print_valid_twists, expose_value=False, type=int, is_eager=True, help='Calculate and show valid --twists counts for the given number of turns. Takes the number of turns as a value.')
@click.option('--clearance', type=float, default=None)
@click.option('--arc-tolerance', type=float, default=0.02)
@click.option('--mesh-out', type=click.Path(writable=True, dir_okay=False, path_type=Path))
@click.option('--mag-mesh-out', type=click.Path(writable=True, dir_okay=False, path_type=Path))
@click.option('--mag-mesh-mutual-out', type=click.Path(writable=True, dir_okay=False, path_type=Path))
@click.option('--mutual-offset-x', type=float, default=0)
@click.option('--mutual-offset-y', type=float, default=0)
@click.option('--mutual-offset-z', type=float, default=5)
@click.option('--mutual-rotation-z', type=float, default=0)
@click.option('--magneticalc-out', type=click.Path(writable=True, dir_okay=False, path_type=Path))
@click.option('--clipboard/--no-clipboard', help='Use clipboard integration (requires wl-clipboard)')
@click.option('--counter-clockwise/--clockwise', help='Direction of generated spiral. Default: clockwise when wound from the inside.')
@click.version_option()
def generate(outfile, turns, outer_diameter, inner_diameter, via_diameter, via_drill, via_offset, trace_width, clearance,
footprint_name, layer_pair, twists, clipboard, counter_clockwise, keepout_zone, keepout_margin,
arc_tolerance, pcb, mesh_out, magneticalc_out, circle_segments, mag_mesh_out, copper_thickness,
board_thickness, mag_mesh_mutual_out, mutual_offset_x, mutual_offset_y, mutual_offset_z, mutual_rotation_z,
two_layer):
if 'WAYLAND_DISPLAY' in os.environ:
copy, paste, cliputil = ['wl-copy'], ['wl-paste'], 'xclip'
else:
copy, paste, cliputil = ['xclip', '-i', '-sel', 'clipboard'], ['xclip', '-o', '-sel' 'clipboard'], 'wl-clipboard'
if gcd(twists, turns) != 1:
raise click.ClickException('For the geometry to work out, the --twists parameter must be co-prime to --turns, i.e. the two must have 1 as their greatest common divisor. You can print valid values for --twists by running this command with --show-twists [turns number].')
if mesh_out and not pcb:
raise click.ClickException('--pcb is required when --mesh-out is used.')
if magneticalc_out and not pcb:
raise click.ClickException('--pcb is required when --magneticalc-out is used.')
outer_radius = outer_diameter/2
inner_radius = inner_diameter/2
turns_per_layer = turns/2 if two_layer else turns
sweeping_angle = 2*pi * turns_per_layer / twists
spiral_pitch = (outer_radius-inner_radius) / turns_per_layer
c1 = inner_radius
c2 = inner_radius + spiral_pitch
alpha1 = atan((outer_radius - inner_radius) / sweeping_angle / c1)
alpha2 = atan((outer_radius - inner_radius) / sweeping_angle / c2)
alpha = (alpha1+alpha2)/2
projected_spiral_pitch = spiral_pitch*cos(alpha)
if trace_width is None and clearance is None:
trace_width = 0.15
print(f'Warning: Defaulting to {trace_width:.2f} mm trace width.', file=sys.stderr)
if trace_width is None:
if clearance > projected_spiral_pitch:
raise click.ClickException(f'Error: Given clearance of {clearance:.2f} mm is larger than the projected spiral pitch of {projected_spiral_pitch:.2f} mm. Reduce clearance or increase the size of the coil.')
trace_width = projected_spiral_pitch - clearance
print(f'Calculated trace width for {clearance:.2f} mm clearance is {trace_width:.2f} mm.', file=sys.stderr)
elif clearance is None:
if trace_width > projected_spiral_pitch:
raise click.ClickException(f'Error: Given trace width of {trace_width:.2f} mm is larger than the projected spiral pitch of {projected_spiral_pitch:.2f} mm. Reduce clearance or increase the size of the coil.')
clearance = projected_spiral_pitch - trace_width
print(f'Calculated clearance for {trace_width:.2f} mm trace width is {clearance:.2f} mm.', file=sys.stderr)
else:
if trace_width > projected_spiral_pitch:
raise click.ClickException(f'Error: Given trace width of {trace_width:.2f} mm is larger than the projected spiral pitch of {projected_spiral_pitch:.2f} mm. Reduce clearance or increase the size of the coil.')
clearance_actual = projected_spiral_pitch - trace_width
if clearance_actual < clearance:
raise click.ClickException(f'Error: Actual clearance for {trace_width:.2f} mm trace is {clearance_actual:.2f} mm, which is lower than the given clearance of {clearance:.2f} mm.')
if via_diameter < trace_width:
print(f'Clipping via diameter from {via_diameter:.2f} mm to trace width of {trace_width:.2f} mm.', file=sys.stderr)
via_diameter = trace_width
if via_offset is None:
via_offset = max(0, (via_diameter-trace_width)/2)
print(f'Autocalculated via offset {via_offset:.2f} mm', file=sys.stderr)
inner_via_ring_radius = inner_radius - via_offset
#print(f'{inner_radius=} {via_offset=} {via_diameter=}', file=sys.stderr)
inner_via_angle = 2*asin((via_diameter + clearance)/2 / inner_via_ring_radius)
outer_via_ring_radius = outer_radius + via_offset
outer_via_angle = 2*asin((via_diameter + clearance)/2 / outer_via_ring_radius)
print(f'Inner via ring @r={inner_via_ring_radius:.2f} mm (from {inner_radius:.2f} mm)', file=sys.stderr)
print(f' {degrees(inner_via_angle):.1f} deg / via', file=sys.stderr)
print(f'Outer via ring @r={outer_via_ring_radius:.2f} mm (from {outer_radius:.2f} mm)', file=sys.stderr)
print(f' {degrees(outer_via_angle):.1f} deg / via', file=sys.stderr)
# Check if the vias of the inner ring are so large that they would overlap
if inner_via_angle*twists > 2*pi:
min_dia = 2*((via_diameter + clearance) / (2*sin(pi / twists)) + via_offset)
raise click.ClickException(f'Error: Overlapping vias in inner via ring. Calculated minimum inner diameter is {min_dia:.2f} mm.')
pitch = clearance + trace_width
t, _, b = layer_pair.partition(',')
layer_pair = (t.strip(), b.strip())
rainbow = '#817 #a35 #c66 #e94 #ed0 #9d5 #4d8 #2cb #0bc #09c #36b #639'.split()
rainbow = rainbow[2::3] + rainbow[1::3] + rainbow[0::3]
n = 5
rainbow = rainbow[n:] + rainbow[:n]
out_paths = []
svg_stuff = [*out_paths]
# For fill factor & inductance formulas, See https://coil32.net/pcb-coil.html for details
d_avg = (outer_diameter + inner_diameter)/2
phi = (outer_diameter - inner_diameter) / (outer_diameter + inner_diameter)
c1, c2, c3, c4 = 1.00, 2.46, 0.00, 0.20
L = mu_0 * turns**2 * d_avg*1e3 * c1 / 2 * (log(c2/phi) + c3*phi + c4*phi**2)
print(f'Outer diameter: {outer_diameter:g} mm', file=sys.stderr)
print(f'Average diameter: {d_avg:g} mm', file=sys.stderr)
print(f'Inner diameter: {inner_diameter:g} mm', file=sys.stderr)
print(f'Fill factor: {phi:g}', file=sys.stderr)
print(f'Approximate inductance: {L:g} µH', file=sys.stderr)
make_pad = lambda num, layer, x, y: kicad_fp.Pad(
number=str(num),
type=kicad_fp.Atom.smd,
shape=kicad_fp.Atom.circle,
at=kicad_fp.AtPos(x=x, y=y),
size=kicad_fp.XYCoord(x=trace_width, y=trace_width),
layers=layer,
clearance=clearance,
zone_connect=0)
make_line = lambda x1, y1, x2, y2, layer: kicad_fp.Line(
start=kicad_fp.XYCoord(x=x1, y=y1),
end=kicad_fp.XYCoord(x=x2, y=y2),
layer=layer,
stroke=kicad_fp.Stroke(width=trace_width))
make_arc = lambda x1, y1, x2, y2, xm, ym, layer: kicad_fp.Arc(
start=kicad_fp.XYCoord(x=x1, y=y1),
mid=kicad_fp.XYCoord(x=xm, y=ym),
end=kicad_fp.XYCoord(x=x2, y=y2),
layer=layer,
stroke=kicad_fp.Stroke(width=trace_width))
make_via = lambda x, y, layers: kicad_fp.Pad(number="NC",
type=kicad_fp.Atom.thru_hole,
shape=kicad_fp.Atom.circle,
at=kicad_fp.AtPos(x=x, y=y),
size=kicad_fp.XYCoord(x=via_diameter, y=via_diameter),
drill=kicad_fp.Drill(diameter=via_drill),
layers=layers,
clearance=clearance,
zone_connect=0)
pads = []
lines = []
arcs = []
def arc_approximate(points, layer, tolerance=0.02, level=0):
indent = ' ' * level
#print(f'{indent}arc_approximate {len(points)=}', file=sys.stderr)
if len(points) < 3:
raise ValueError()
i_mid = len(points)//2
x0, y0 = points[0]
x1, y1 = points[i_mid]
x2, y2 = points[-1]
if len(points) < 5:
#print(f'{indent} -> interp last points', file=sys.stderr)
yield make_arc(x0, y0, x2, y2, x1, y1, layer)
# https://stackoverflow.com/questions/56224824/how-do-i-find-the-circumcenter-of-the-triangle-using-python-without-external-lib
d = 2 * (x0 * (y2 - y1) + x2 * (y1 - y0) + x1 * (y0 - y2))
cx = ((x0 * x0 + y0 * y0) * (y2 - y1) + (x2 * x2 + y2 * y2) * (y1 - y0) + (x1 * x1 + y1 * y1) * (y0 - y2)) / d
cy = ((x0 * x0 + y0 * y0) * (x1 - x2) + (x2 * x2 + y2 * y2) * (x0 - x1) + (x1 * x1 + y1 * y1) * (x2 - x0)) / d
r = dist((cx, cy), (x1, y1))
if any(abs(dist((px, py), (cx, cy)) - r) > tolerance for px, py in points):
#print(f'{indent} -> split', file=sys.stderr)
yield from arc_approximate(points[:i_mid+1], layer, tolerance, level+1)
yield from arc_approximate(points[i_mid:], layer, tolerance, level+1)
else:
yield make_arc(x0, y0, x2, y2, x1, y1, layer)
#print(f'{indent} -> good fit', file=sys.stderr)
def do_spiral(layer, r1, r2, a1, a2, start_frac, end_frac, fn=64):
use_arcs = not pcb
fn = ceil(fn * (a2-a1)/(2*pi))
x0, y0 = cos(a1)*r1, sin(a1)*r1
direction = '↓' if r2 < r1 else '↑'
dr = 3 if r2 < r1 else -3
label = f'{direction} {degrees(a1):.0f}'
svg_stuff.append(Tag('text',
[label],
x=str(x0 + cos(a1)*dr),
y=str(y0 + sin(a1)*dr),
text_anchor='middle',
style=f'font: 1px bold sans-serif; fill: {rainbow[layer%len(rainbow)]}'))
xn, yn = x0, y0
points = [(x0, y0)]
dists = []
for i in range(fn):
r, g, b, _a = mpl.cm.plasma(start_frac + (end_frac - start_frac)/fn * (i + 0.5))
path = SVGPath(fill='none', stroke=f'#{round(r*255):02x}{round(g*255):02x}{round(b*255):02x}', stroke_width=trace_width, stroke_linejoin='round', stroke_linecap='round')
svg_stuff.append(path)
xp, yp = xn, yn
r = r1 + (i+1)*(r2-r1)/fn
a = a1 + (i+1)*(a2-a1)/fn
xn, yn = cos(a)*r, sin(a)*r
path.move(xp, yp)
path.line(xn, yn)
points.append((xn, yn))
dists.append(dist((xp, yp), (xn, yn)))
if not use_arcs:
lines.append(make_line(xp, yp, xn, yn, layer_pair[layer]))
if use_arcs:
arcs.extend(arc_approximate(points, layer_pair[layer], arc_tolerance))
svg_stuff.append(Tag('text',
[label],
x=str(xn + cos(a2)*-dr),
y=str(yn + sin(a2)*-dr + 1.2),
text_anchor='middle',
style=f'font: 1px bold sans-serif; fill: {rainbow[layer%len(rainbow)]}'))
return (x0, y0), (xn, yn), sum(dists)
sector_angle = 2*pi / twists
total_angle = twists*2*sweeping_angle if two_layer else twists*sweeping_angle
inverse = {}
for i in range(twists):
inverse[i*turns%twists] = i
svg_vias = []
for i in range(twists):
start_angle = i*sector_angle
fold_angle = start_angle + sweeping_angle
end_angle = fold_angle + sweeping_angle
x = inverse[i]*floor(2*sweeping_angle / (2*pi)) * 2*pi
(x0, y0), (xn, yn), clen = do_spiral(0, outer_radius, inner_radius, start_angle, fold_angle, (x + start_angle)/total_angle, (x + fold_angle)/total_angle, circle_segments)
if two_layer:
do_spiral(1, inner_radius, outer_radius, fold_angle, end_angle, (x + fold_angle)/total_angle, (x + end_angle)/total_angle)
else:
dr = outer_radius - inner_radius
xq = xn + cos(fold_angle) * dr
yq = yn - sin(fold_angle) * dr
lines.append(make_line(xn, yn, xq, yq, layer_pair[1]))
r, g, b, _a = mpl.cm.plasma((x + fold_angle)/total_angle)
path = SVGPath(fill='none', stroke=f'#{round(r*255):02x}{round(g*255):02x}{round(b*255):02x}', stroke_width=trace_width, stroke_linejoin='round', stroke_linecap='round')
svg_stuff.append(path)
path.move(xn, yn)
path.line(xq, yq)
xv, yv = inner_via_ring_radius*cos(fold_angle), inner_via_ring_radius*sin(fold_angle)
pads.append(make_via(xv, yv, layer_pair))
if not isclose(via_offset, 0, abs_tol=1e-6):
lines.append(make_line(xn, yn, xv, yv, layer_pair[0]))
lines.append(make_line(xn, yn, xv, yv, layer_pair[1]))
svg_vias.append(Tag('circle', cx=xv, cy=yv, r=via_diameter/2, stroke='none', fill='white'))
svg_vias.append(Tag('circle', cx=xv, cy=yv, r=via_drill/2, stroke='none', fill='black'))
if i > 0:
xv, yv = outer_via_ring_radius*cos(start_angle), outer_via_ring_radius*sin(start_angle)
pads.append(make_via(xv, yv, layer_pair))
if not isclose(via_offset, 0, abs_tol=1e-6):
lines.append(make_line(x0, y0, xv, yv, layer_pair[0]))
lines.append(make_line(x0, y0, xv, yv, layer_pair[1]))
svg_vias.append(Tag('circle', cx=xv, cy=yv, r=via_diameter/2, stroke='none', fill='white'))
svg_vias.append(Tag('circle', cx=xv, cy=yv, r=via_drill/2, stroke='none', fill='black'))
l_total = clen*twists*2
print(f'Approximate track length: {l_total:.2f} mm', file=sys.stderr)
A = copper_thickness/1e3 * trace_width/1e3
rho = 1.68e-8
R = l_total/1e3 * rho / A
print(f'Approximate resistance: {R:g} Ω', file=sys.stderr)
top_pad = make_pad(1, [layer_pair[0]], outer_radius, 0)
pads.append(top_pad)
bottom_pad = make_pad(2, [layer_pair[1]], outer_radius, 0)
pads.append(bottom_pad)
svg_stuff += svg_vias
svg_stuff.append(Tag('path', d=f'M {inner_radius} 0 L {outer_radius} 0', stroke=rainbow[n+1], fill='none',
stroke_width='0.05mm', stroke_linecap='round'))
ntraces = int(turns_per_layer)+1
alpha = [0] * ntraces
for i in range(ntraces):
c = inner_radius + (outer_radius-inner_radius) / turns_per_layer * i
#dalpha = dy / c
#dx / dalpha = (outer_radius - inner_radius) / sweeping_angle
#c * (dx / dy) = (outer_radius - inner_radius) / sweeping_angle
#dx / dy = (outer_radius - inner_radius) / sweeping_angle / c
dx = (outer_radius - inner_radius) / sweeping_angle / c
alpha[i] = atan(dx)
dy = 0.3
dx *= dy
r = trace_width/2 / cos(alpha[i])
svg_stuff.append(Tag('path', d=f'M {c-r+dx} {-dy} L {c-r-dx} {dy}', stroke=rainbow[n+1], fill='none',
stroke_width='0.05mm', stroke_linecap='round'))
svg_stuff.append(Tag('path', d=f'M {c+r+dx} {-dy} L {c+r-dx} {dy}', stroke=rainbow[n+1], fill='none',
stroke_width='0.05mm', stroke_linecap='round'))
#print(f'spiral angle {degrees(alpha[i]):.2f}', file=sys.stderr)
for i, (a1, a2) in enumerate(zip(alpha[::-1], alpha[1::])):
amean = (a2+a1)/2
pitch = (outer_radius - inner_radius) / turns_per_layer
clearance = pitch - trace_width
clearance *= cos(amean)
x, y = inner_radius + (i + 1/2)*pitch, -0.5
svg_stuff.append(Tag('text',
[f'{clearance:.5f}mm'],
x=x,
y=y,
text_anchor='start',
transform=f'rotate(-45 {x} {y})',
style=f'font: 1px bold sans-serif; fill: {rainbow[n+1]}'))
svg_file('/tmp/test.svg', svg_stuff, 100, 100, -50, -50)
if footprint_name:
name = footprint_name
elif outfile:
name = outfile.stem,
else:
name = 'generated_coil'
if keepout_zone:
r = outer_diameter/2 + keepout_margin
tol = 0.05 # mm
n = ceil(pi / acos(1 - tol/r))
pts = [(r*cos(a*2*pi/n), r*sin(a*2*pi/n)) for a in range(n)]
zones = [kicad_pr.Zone(layers=['*.Cu'],
hatch=kicad_pr.Hatch(),
filled_areas_thickness=False,
keepout=kicad_pr.ZoneKeepout(copperpour_allowed=False),
polygon=kicad_pr.ZonePolygon(pts=kicad_pr.PointList(xy=[kicad_pr.XYCoord(x=x, y=y) for x, y in pts])))]
else:
zones = []
if pcb:
obj = kicad_pcb.Board.empty_board(
zones=zones,
track_segments=[kicad_pcb.TrackSegment.from_footprint_line(line) for line in lines],
vias=[kicad_pcb.Via.from_pad(pad) for pad in pads if pad.type == kicad_pcb.Atom.thru_hole])
obj.rebuild_trace_index()
seg = obj.track_segments[-1]
traces = []
end = top_pad
layer = 'F.Cu'
while True:
tr = list(obj.find_connected_traces(end, layers=[layer]))
traces.append(tr)
if not isinstance(tr[-1], kicad_pcb.Via):
break
layer = 'B.Cu' if layer == 'F.Cu' else 'F.Cu'
end = tr[-1]
# remove start pad
traces[0] = traces[0][1:]
r = outer_diameter/2 + 20
if mesh_out:
traces_to_gmsh(traces, mesh_out, ((-r, -r), (r, r)), copper_thickness=copper_thickness, board_thickness=board_thickness)
if mag_mesh_out:
traces_to_gmsh_mag(traces, mag_mesh_out, ((-r, -r), (r, r)), copper_thickness=copper_thickness, board_thickness=board_thickness)
if mag_mesh_mutual_out:
m_dx, m_dy, m_dz = mutual_offset_x, mutual_offset_y, mutual_offset_z
mutual_rotation_z = math.radians(mutual_rotation_z)
traces_to_gmsh_mag_mutual(traces, mag_mesh_mutual_out, ((-r, -r), (r, r)),
copper_thickness=copper_thickness, board_thickness=board_thickness,
mutual_offset=(m_dx, m_dy, m_dz), mutual_rotation=(0, 0, mutual_rotation_z))
if magneticalc_out:
traces_to_magneticalc(traces, magneticalc_out)
# for trace in traces:
# print(f'Trace {i}', file=sys.stderr)
# print(f' Length: {len(trace)}', file=sys.stderr)
# print(f' Start: {trace[0]}', file=sys.stderr)
# print(f' End: {trace[-1]}', file=sys.stderr)
# print(f' Layer: {trace[1].layer}', file=sys.stderr)
#for e in obj.find_connected_traces(seg, layers=seg.layer_mask):
# print(getattr(e, 'layer', ''), str(e)[:80], file=sys.stderr)
#nodes, edges = obj.track_skeleton(pads[-1])
#for node, node_edges in edges.items():
# print(f'Node {node} with {len(node_edges)} edges', file=sys.stderr)
# for i, e in enumerate(node_edges):
# print(f' Edge {i}', file=sys.stderr)
# for elem in e:
# print(' ', elem, file=sys.stderr)
else:
obj = kicad_fp.Footprint(
name=name,
generator=kicad_fp.Atom('GerbonaraTwistedCoilGenV1'),
layer='F.Cu',
descr=f"{turns} turn {outer_diameter:.2f} mm diameter twisted coil footprint, inductance approximately {L:.6f} µH. Generated by gerbonara'c Twisted Coil generator, version {__version__}.",
clearance=clearance,
zone_connect=0,
lines=lines,
arcs=arcs,
pads=pads,
zones=zones,
)
if clipboard:
try:
data = obj.serialize()
print(f'Running {copy[0]}.', file=sys.stderr)
proc = subprocess.Popen(copy, stdin=subprocess.PIPE, text=True)
proc.communicate(data)
print('passed to wl-clip:', data)
except FileNotFoundError:
print(f'Error: --clipboard requires the {copy[0]} and {paste[0]} utilities from {cliputil} to be installed.', file=sys.stderr)
elif not outfile:
print(obj.serialize())
else:
obj.write(outfile)
if __name__ == '__main__':
generate()