commit 59261205579ab88730f8b297e44d48304b408e05
Author: Chris Greening <chris@cmgresearch.com>
Date:   Wed Sep 28 10:20:08 2022 +0100

    Working coil

diff --git a/coil_plugin.py b/coil_plugin.py
new file mode 100644
index 0000000..efee2f8
--- /dev/null
+++ b/coil_plugin.py
@@ -0,0 +1,88 @@
+import pcbnew
+import numpy as np
+
+VIA_DIAM = 0.8
+VIA_DRILL = 0.4
+TRACK_THICKNESS = 0.2
+TRACK_SPACING = 0.2
+SEGMENT_LENGTH = 2 * 2*np.pi/360.0
+STATOR_RADIUS = 20
+STATOR_HOLE_RADIUS = 4
+INNER_RADIUS = 1
+# each coil is in the middle of the stator radius
+OUTER_RADIUS = (0.5 * STATOR_RADIUS * np.pi) / 6 - TRACK_SPACING
+
+
+def spiral(angle, distance, inner_radius, outer_radius, track_width, track_spacing, direction=1):
+    thickness = track_width + track_spacing
+    number_turns = (outer_radius - inner_radius)//thickness
+    # create a starting point in the center
+    yield distance * np.cos(angle), distance * np.sin(angle)
+    for theta in np.arange(0, number_turns * 2*np.pi, 0.1):
+        radius = inner_radius + thickness * theta/(2*np.pi)
+        if direction == -1:
+            x = radius*np.cos(direction * (theta + np.pi))
+            y = radius*np.sin(direction * (theta + np.pi))
+        else:
+            x = radius*np.cos(direction * (theta))
+            y = radius*np.sin(direction * (theta))
+        # rotate by angle
+        x, y = x*np.cos(angle) - y*np.sin(angle), x*np.sin(angle) + y*np.cos(angle)
+        # translate by distance
+        x, y = x + distance * np.cos(angle), y + distance * np.sin(angle)
+        yield x, y
+
+
+def create_tracks(board, group, coords, layer):
+    last_x = None
+    last_y = None
+    for x, y in coords:
+        track = pcbnew.PCB_TRACK(board)
+        if last_x is not None:
+            track.SetStart(pcbnew.wxPointMM(float(last_x), float(last_y)))
+            track.SetEnd(pcbnew.wxPointMM(float(x), float(y)))
+            track.SetWidth(int(TRACK_THICKNESS * 1e6))
+            track.SetLayer(layer)
+            board.Add(track)
+            group.AddItem(track)
+        last_x = x
+        last_y = y
+
+
+class CoilPlugin(pcbnew.ActionPlugin):
+    def defaults(self):
+        self.name = "Create coil 2"
+        self.category = "Coils"
+        self.description = "Creates a coil"
+        # self.show_toolbar_button = False # Optional, defaults to False
+        # self.icon_file_name = os.path.join(os.path.dirname(__file__), 'simple_plugin.png') # Optional, defaults to ""
+
+    def Run(self):
+        board = pcbnew.GetBoard()
+        # create the center hole
+        arc = pcbnew.PCB_SHAPE(board)
+        arc.SetShape(pcbnew.SHAPE_T_ARC)
+        arc.SetStart(pcbnew.wxPointMM(STATOR_HOLE_RADIUS, 0))
+        arc.SetCenter(pcbnew.wxPointMM(0, 0))
+        arc.SetArcAngleAndEnd(0, False)
+        arc.SetLayer(pcbnew.Edge_Cuts)
+        arc.SetWidth(int(0.1 * pcbnew.IU_PER_MM))
+        board.Add(arc)
+        # create six coils equally spaced around the origin
+        for angle in np.arange(0, 2*np.pi, 2*np.pi/6):
+            group = pcbnew.PCB_GROUP(board)
+            board.Add(group)
+
+            coords = spiral(angle, STATOR_RADIUS/2, INNER_RADIUS, OUTER_RADIUS, TRACK_THICKNESS, TRACK_SPACING, 1)
+            create_tracks(board, group, coords, pcbnew.F_Cu)
+            coords = spiral(angle, STATOR_RADIUS/2, INNER_RADIUS, OUTER_RADIUS, TRACK_THICKNESS, TRACK_SPACING, -1)
+            create_tracks(board, group, coords, pcbnew.B_Cu)
+            via = pcbnew.PCB_VIA(board)
+            via.SetPosition(pcbnew.wxPointMM(float(STATOR_RADIUS/2 * np.cos(angle)), float(STATOR_RADIUS/2 * np.sin(angle))))
+            via.SetWidth(int(VIA_DIAM * 1e6))
+            via.SetDrill(int(VIA_DRILL * 1e6))
+            board.Add(via)
+            group.AddItem(via)
+
+
+CoilPlugin().register()  # Instantiate and register to Pcbnew