Multilayer coil WIP

1 files changed, 294 insertions, 0 deletions

diff --git a/twisted_coil_gen_twolayer.py b/twisted_coil_gen_twolayer.py
new file mode 100644
index 0000000..574b8b8
--- /dev/null
+++ b/twisted_coil_gen_twolayer.py
@@ -0,0 +1,294 @@
+#!/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'<path {attrs} d="{self.d.rstrip()}"/>'
+
+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'<circle {attrs} r="{self.r}" cx="{self.cx}" cy="{self.cy}"/>'
+
+def svg_file(fn, stuff, vbw, vbh, vbx=0, vby=0):
+    with open(fn, 'w') as f:
+        f.write('<?xml version="1.0" standalone="no"?>\n')
+        f.write('<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">\n')
+        f.write(f'<svg version="1.1" width="{vbw*4}mm" height="{vbh*4}mm" viewBox="{vbx} {vby} {vbw} {vbh}" style="background-color: #333" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">>\n')
+
+        for foo in stuff:
+            f.write(str(foo))
+
+        f.write('</svg>\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()