#!/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 from gerbonara.utils import Tag 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-layers', default='F.Cu,B.Cu', help="Target KiCad layers for the generated footprint. Default: F.Cu,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('--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_layers, 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' pitch = clearance + trace_width target_layers = [name.strip() for name in target_layers.split(',')] via_diameter = max(trace_width, via_diameter) rainbow = '#817 #a35 #c66 #e94 #ed0 #9d5 #4d8 #2cb #0bc #09c #36b #639'.split() rainbow = rainbow[2::3] + rainbow[1::3] + rainbow[0::3] out_paths = [SVGPath(fill='none', stroke=rainbow[i%len(rainbow)], stroke_width=trace_width, stroke_linejoin='round', stroke_linecap='round') for i in range(len(target_layers))] svg_stuff = [*out_paths] # 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', file=sys.stderr) print(f'Average diameter: {d_avg:g} mm', file=sys.stderr) print(f'Inner diameter: {d_inside: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, 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: 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: 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, 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 = [] turns_per_layer = ceil((turns-1) / len(target_layers)) print(f'Splitting {turns} turns into {len(target_layers)} layers using {turns_per_layer} turns per layer plus one weaving turn.', file=sys.stderr) sector_angle = 2*pi / turns_per_layer ### DELETE THIS: d_inside = diameter/2 # FIXME DEBUG ### def do_spiral(path, r1, r2, a1, a2, layer, fn=64): x0, y0 = cos(a1)*r1, sin(a1)*r1 path.move(x0, y0) 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), style=f'font: 1px bold sans-serif; fill: {path.attrs["stroke"]}')) for i in range(fn+1): r = r1 + i*(r2-r1)/fn a = a1 + i*(a2-a1)/fn xn, yn = cos(a)*r, sin(a)*r path.line(xn, yn) svg_stuff.append(Tag('text', [label], x=str(xn + cos(a2)*-dr), y=str(yn + sin(a2)*-dr + 1.2), style=f'font: 1px bold sans-serif; fill: {path.attrs["stroke"]}')) print(f'{turns=} {turns_per_layer=} {len(target_layers)=}', file=sys.stderr) start_radius = d_inside/2 end_radius = diameter/2 inner_via_ring_radius = start_radius - via_diameter/2 inner_via_angle = 2*asin(via_diameter/2 / inner_via_ring_radius) outer_via_ring_radius = end_radius + via_diameter/2 outer_via_angle = 2*asin(via_diameter/2 / outer_via_ring_radius) print(f'inner via ring @ {inner_via_ring_radius:.2f} mm (from {start_radius:.2f} mm)', file=sys.stderr) print(f' {degrees(inner_via_angle):.1f} deg / via', file=sys.stderr) print(f'outer via ring @ {outer_via_ring_radius:.2f} mm (from {end_radius:.2f} mm)', file=sys.stderr) print(f' {degrees(outer_via_angle):.1f} deg / via', file=sys.stderr) for n in range(turns-1): layer_n = n % len(target_layers) layer = target_layers[layer_n] layer_turn = floor(n / len(target_layers)) print(f' {layer_n=} {layer_turn=}', file=sys.stderr) start_angle = sector_angle * (layer_turn - layer_n / len(target_layers)) end_angle = start_angle + (turns_per_layer + 1/len(target_layers)) * sector_angle if layer_n % 2 == 1: start_radius, end_radius = end_radius, start_radius do_spiral(out_paths[layer_n], start_radius, end_radius, start_angle, end_angle, layer_n) 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]}.', file=sys.stderr) 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()