#!/usr/bin/env python3 import subprocess import sys import os from math import * from pathlib import Path from itertools import cycle from scipy.constants import mu_0 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 import click __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 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') for foo in stuff: f.write(str(foo)) f.write('\n') @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('--target-layer', default='F.Cu', help="Target KiCad layer for the generated footprint. Default: F.Cu.") @click.option('--jumper-layer', default='B.Cu', help="KiCad layer for jumper connections. Default: B.Cu.") @click.option('--turns', type=int, default=5, help='Number of turns') @click.option('--diameter', type=float, default=50, help='Outer diameter [mm]') @click.option('--trace-width', type=float, default=0.15) @click.option('--via-diameter', type=float, default=0.6) @click.option('--via-drill', type=float, default=0.3) @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('--twist-width', type=float, default=20, help='Width of twist versus straight coil in percent (0-100, default: 20)') @click.option('--num-twists', type=int, default=1, help='Number of twists per revolution (default: 1)') @click.option('--clearance', type=float, default=0.15) @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.') def generate(outfile, turns, diameter, via_diameter, via_drill, trace_width, clearance, footprint_name, target_layer, jumper_layer, twist_width, num_twists, clipboard, counter_clockwise, keepout_zone, keepout_margin): 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' out_path = SVGPath(fill='none', stroke='black', stroke_width=trace_width, stroke_linejoin='round', stroke_linecap='round') jumper_path = SVGPath(fill='none', stroke='gray', stroke_width=trace_width, stroke_linejoin='round', stroke_linecap='round') svg_stuff = [jumper_path, out_path] pitch = clearance + trace_width twist_angle = 2*pi / (turns * num_twists - 1) twist_width = twist_angle * twist_width/100 via_diameter = max(trace_width, via_diameter) # See https://coil32.net/pcb-coil.html for details d_inside = diameter - 2*(pitch*turns - clearance) d_avg = (diameter + d_inside)/2 phi = (diameter - d_inside) / (diameter + d_inside) 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: {diameter:g} mm') print(f'Average diameter: {d_avg:g} mm') print(f'Inner diameter: {d_inside:g} mm') print(f'Fill factor: {phi:g}') print(f'Approximate inductance: {L:g} µH') make_pad = lambda num, 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=[target_layer], clearance=clearance, zone_connect=0) make_line = lambda x1, y1, x2, y2, layer=target_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, xc, yc, layer=target_layer: kicad_fp.Arc( start=kicad_fp.XYCoord(x=x1, y=y1), mid=kicad_fp.XYCoord(x=xc, y=yc), end=kicad_fp.XYCoord(x=x2, y=y2), layer=layer, stroke=kicad_fp.Stroke(width=trace_width)) make_via = lambda x, y: 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=[target_layer, jumper_layer], clearance=clearance, zone_connect=0) pads = [] lines = [] arcs = [] for n in range(turns * num_twists - 1): for k in range(turns): r = diameter/2 - trace_width/2 - k*pitch a1 = n*twist_angle + twist_width/2 a2 = a1 + twist_angle - twist_width x1, y1 = r*cos(a1), r*sin(a1) out_path.move(x1, y1) x2, y2 = r*cos(a2), r*sin(a2) out_path.line(x2, y2) a3 = (a1 + a2) / 2 xm, ym = r*cos(a3), r*sin(a3) arcs.append(make_arc(x2, y2, x1, y1, xm, ym)) for k in range(turns-1): r1 = diameter/2 - trace_width/2 - (k+1)*pitch r2 = diameter/2 - trace_width/2 - k*pitch a1 = n*twist_angle - twist_width/2 a2 = a1 + twist_width x1, y1 = r1*cos(a1), r1*sin(a1) out_path.move(x1, y1) x2, y2 = r2*cos(a2), r2*sin(a2) out_path.line(x2, y2) a3 = (a1 + a2) / 2 r3 = (r1 + r2) / 2 xm, ym = r3*cos(a3), r3*sin(a3) arcs.append(make_arc(x2, y2, x1, y1, xm, ym)) rs = diameter/2 - trace_width/2 rv = rs - trace_width/2 + via_diameter/2 a = n*twist_angle - twist_width/2 x1, y1 = rs*cos(a), rs*sin(a) out_path.move(x1, y1) xv1, yv1 = rv*cos(a), rv*sin(a) out_path.line(xv1, yv1) svg_stuff.append(SVGCircle(via_diameter/2, xv1, yv1, fill='red')) pads.append(make_via(xv1, yv1)) jumper_path.move(xv1, yv1) lines.append(make_line(x1, y1, xv1, yv1)) a += twist_width rs = diameter/2 - trace_width/2 - (turns-1)*pitch rv = rs + trace_width/2 - via_diameter/2 x1, y1 = rs*cos(a), rs*sin(a) out_path.move(x1, y1) xv2, yv2 = rv*cos(a), rv*sin(a) out_path.line(xv2, yv2) svg_stuff.append(SVGCircle(via_diameter/2, xv2, yv2, fill='red')) pads.append(make_via(xv2, yv2)) lines.append(make_line(x1, y1, xv2, yv2)) if n > 0: jumper_path.line(xv2, yv2) lines.append(make_line(xv1, yv1, xv2, yv2, jumper_layer)) else: pads.append(make_pad(1, xv1, yv1)) pads.append(make_pad(2, xv2, yv2)) svg_file('/tmp/test.svg', svg_stuff, 100, 100, -50, -50) if counter_clockwise: for p in pads: p.at.y = -p.at.y for l in lines: l.start.y = -l.start.y l.end.y = -l.end.y for a in arcs: a.start.y = -a.start.y a.end.y = -a.end.y if footprint_name: name = footprint_name elif outfile: name = outfile.stem, else: name = 'generated_coil' if keepout_zone: r = 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 = [] fp = kicad_fp.Footprint( name=name, generator=kicad_fp.Atom('GerbonaraTwistedCoilGenV1'), layer='F.Cu', descr=f"{turns} turn {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: print(f'Running {copy[0]}.') proc = subprocess.Popen(copy, stdin=subprocess.PIPE, text=True) proc.communicate(fp.serialize()) 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(fp.serialize()) else: fp.write(outfile) if __name__ == '__main__': generate()