feat: implement PDIP footprint (Plastic DIP)

src/fn/index.ts

@@ -1,4 +1,5 @@
 export { dip } from "./dip"
+export { pdip } from "./pdip"
 export { diode } from "./diode"
 export { cap } from "./cap"
 export { led } from "./led"

src/fn/pdip.ts

@@ -0,0 +1,133 @@
+import type {
+  AnyCircuitElement,
+  PcbFabricationNoteText,
+  PcbSilkscreenPath,
+} from "circuit-json"
+import { type SilkscreenRef, silkscreenRef } from "src/helpers/silkscreenRef"
+import { platedHolePill } from "../helpers/platedHolePill"
+import { platedHoleWithRectPad } from "../helpers/platedHoleWithRectPad"
+import { u_curve } from "../helpers/u-curve"
+import { getCcwDipCoords, extendDipDef } from "./dip"
+
+/**
+ * PDIP (Plastic Dual In-line Package) footprint.
+ *
+ * PDIP differs from standard DIP by using oblong/oval pads instead of
+ * circular pads. Typical PDIP-8 dimensions (matching KiCad DIP-8_W7.62mm_LongPads):
+ *   - Row spacing (w): 7.62mm (300mil)
+ *   - Pin pitch (p): 2.54mm (100mil)
+ *   - Hole diameter (id): 0.8mm
+ *   - Pad width (ow): 2.4mm (horizontal, along row direction)
+ *   - Pad height (oh): 1.6mm (vertical, along pitch direction)
+ *
+ * Supports any even pin count (e.g. pdip4, pdip8, pdip14, pdip16, pdip20, pdip28).
+ */
+
+export const pdip_def = extendDipDef({})
+
+export const pdip = (
+  raw_params: Record<string, any>,
+): { circuitJson: AnyCircuitElement[]; parameters: any } => {
+  const params = { ...raw_params, fn: "pdip" }
+  delete params.pdip
+  const parameters = pdip_def.parse(params)
+
+  // PDIP uses oblong pads: wider horizontally than vertically
+  // Default outer width is 1.5x the outer diameter (od)
+  const padWidth = parameters.od * 1.5 // 2.4mm for default od=1.6mm
+  const padHeight = parameters.od // 1.6mm
+
+  const platedHoles: AnyCircuitElement[] = []
+  for (let i = 0; i < parameters.num_pins; i++) {
+    const { x, y } = getCcwDipCoords(
+      parameters.num_pins,
+      i + 1,
+      parameters.w,
+      parameters.p ?? 2.54,
+      parameters.nosquareplating,
+    )
+    if (i === 0 && !parameters.nosquareplating) {
+      // Pin 1 uses a rectangular pad (same oblong dimensions)
+      platedHoles.push(
+        platedHoleWithRectPad({
+          pn: i + 1,
+          x,
+          y,
+          holeDiameter: parameters.id ?? "0.8mm",
+          rectPadWidth: padWidth,
+          rectPadHeight: padHeight,
+        }),
+      )
+      continue
+    }
+    // Non-pin-1 pads use pill (oblong) shape
+    platedHoles.push(
+      platedHolePill(i + 1, x, y, parameters.id ?? 0.8, padWidth, padHeight),
+    )
+  }
+
+  // Silkscreen uses the wider pad dimension for clearance
+  const innerGap = parameters.w - padWidth
+  const sw = innerGap - 1
+
+  const sh = (parameters.num_pins / 2 - 1) * parameters.p + padHeight + 0.4
+
+  const silkscreenBorder: PcbSilkscreenPath = {
+    layer: "top",
+    pcb_component_id: "",
+    pcb_silkscreen_path_id: "silkscreen_path_1",
+    route: [
+      { x: -sw / 2, y: -sh / 2 },
+      { x: -sw / 2, y: sh / 2 },
+      ...u_curve.map(({ x, y }) => ({
+        x: (x * sw) / 6,
+        y: (y * sw) / 6 + sh / 2,
+      })),
+      { x: sw / 2, y: sh / 2 },
+      { x: sw / 2, y: -sh / 2 },
+      { x: -sw / 2, y: -sh / 2 },
+    ],
+    type: "pcb_silkscreen_path",
+    stroke_width: 0.1,
+  }
+
+  const silkscreenPins: PcbFabricationNoteText[] = []
+  for (let i = 0; i < parameters.num_pins; i++) {
+    const isLeft = i < parameters.num_pins / 2
+    const clearance = 0.6
+    const { y: pinCenterY } = getCcwDipCoords(
+      parameters.num_pins,
+      i + 1,
+      parameters.w,
+      parameters.p ?? 2.54,
+      parameters.nosquareplating,
+    )
+    const pinLabelX = isLeft
+      ? -parameters.w / 2 - padWidth / 2 - clearance
+      : parameters.w / 2 + padWidth / 2 + clearance
+    const pinLabelY = pinCenterY
+    silkscreenPins.push({
+      type: "pcb_fabrication_note_text",
+      pcb_fabrication_note_text_id: `pin_${i + 1}`,
+      layer: "top",
+      pcb_component_id: `pin_${i + 1}`,
+      text: `{pin${i + 1}}`,
+      anchor_position: { x: pinLabelX, y: pinLabelY },
+      font_size: 0.3,
+      font: "tscircuit2024",
+      anchor_alignment: "top_left",
+    })
+  }
+
+  const silkscreenRefText: SilkscreenRef = silkscreenRef(0, sh / 2 + 0.5, 0.4)
+
+  return {
+    circuitJson: [
+      ...platedHoles,
+      silkscreenBorder,
+      silkscreenRefText,
+      ...silkscreenPins,
+    ],
+    parameters,
+  }
+}

src/footprinter.ts

@@ -39,6 +39,9 @@ export type Footprinter = {
   dip: (
     num_pins?: number,
   ) => FootprinterParamsBuilder<"w" | "p" | "id" | "od" | "wide" | "narrow">
+  pdip: (
+    num_pins?: number,
+  ) => FootprinterParamsBuilder<"w" | "p" | "id" | "od" | "wide" | "narrow">
   cap: () => FootprinterParamsBuilder<CommonPassiveOptionKey>
   res: () => FootprinterParamsBuilder<CommonPassiveOptionKey>
   diode: () => FootprinterParamsBuilder<CommonPassiveOptionKey>