Add SPDIP-28 footprint with string aliases and SVG tests

README.md

@@ -21,6 +21,7 @@ cap0402
 res0805
 soic8_p1.27mm
 dip16
+SPDIP-28
 pinrow10
 pinrow6_rows2_cols5_p2.54mm_py5.08mm_missing(3,4,8,9)
 smdpinheader6
@@ -33,6 +34,13 @@ do219ad
 sod323he
 ```
 
+`SPDIP-28`, `spdip28`, and `fp().spdip()` generate the 28-pin skinny plastic DIP
+on a 7.62 mm row grid with 2.54 mm pin pitch. These dimensions follow the
+[Microchip C04-070 package drawing](https://ww1.microchip.com/downloads/en/PackagingSpec/00049AA.pdf#page=47).
+The existing DIP generator supplies pin-one marking, silkscreen and courtyard.
+Drill and pad diameters default to 0.8 mm and 1.6 mm; override them to suit your
+fabrication requirements, for example `SPDIP-28_id1mm_od1.8mm`.
+
 You can use these like so:
 
 ```tsx

src/fn/index.ts

@@ -1,4 +1,5 @@
 export { dip } from "./dip"
+export { spdip } from "./spdip"
 export { d2pak } from "./d2pak"
 export { dpak } from "./dpak"
 export { diode } from "./diode"

src/fn/spdip.ts

@@ -0,0 +1,12 @@
+import type { z } from "zod"
+import { dip, dip_def } from "./dip"
+
+/** Skinny plastic DIP: 300 mil row spacing, 100 mil pitch, 28 pins by default. */
+export const spdip = (raw_params: z.input<typeof dip_def>) => {
+  const parameters = dip_def.parse({
+    ...raw_params,
+    num_pins: raw_params.num_pins ?? 28,
+    w: raw_params.w ?? "300mil",
+  })
+  return dip({ ...parameters, dip: true })
+}

src/footprinter.ts

@@ -51,6 +51,9 @@ type CommonPassiveOptionKey =
   | "textbottom"
 
 export type Footprinter = {
+  spdip: (
+    num_pins?: number,
+  ) => FootprinterParamsBuilder<"w" | "p" | "id" | "od" | "nosquareplating">
   dip: (
     num_pins?: number,
   ) => FootprinterParamsBuilder<"w" | "p" | "id" | "od" | "wide" | "narrow">
@@ -633,6 +636,7 @@ export type Footprinter = {
 const normalizeDefinition = (def: string): string => {
   return def
     .trim()
+    .replace(/^spdip-(\d+)(?=_|$)/i, "spdip$1")
     .replace(/^do-219ad(?=_|$)/i, "do219ad")
     .replace(/^sod-323he(?=_|$)/i, "sod323he")
     .replace(/^pinheader(?=[\d_]|$)/i, "pinrow")

tests/spdip.test.ts

@@ -0,0 +1,70 @@
+import { expect, test } from "bun:test"
+import { convertCircuitJsonToPcbSvg } from "circuit-to-svg"
+import { fp, getFootprintNames } from "../src/footprinter"
+
+test("SPDIP-28 uses the 300 mil row spacing and 100 mil pitch", () => {
+  const holes = fp
+    .string("SPDIP-28")
+    .circuitJson()
+    .filter((element) => element.type === "pcb_plated_hole")
+  expect(holes).toHaveLength(28)
+  // Microchip C04-070, 28-lead skinny plastic DIP: 0.100 inch pitch.
+  // Through-hole rows use the 0.300 inch insertion grid, not free lead-tip span.
+  for (let index = 0; index < 28; index++) {
+    const hole = holes[index]!
+    const left = index < 14
+    const expectedY = left ? 16.51 - index * 2.54 : -16.51 + (index - 14) * 2.54
+    expect(hole.x).toBeCloseTo(left ? -3.81 : 3.81, 8)
+    expect(hole.y).toBeCloseTo(expectedY, 8)
+    expect(hole.port_hints).toContain(String(index + 1))
+  }
+  expect(holes[0]!.shape).toBe("circular_hole_with_rect_pad")
+  expect(holes.slice(1).every((hole) => hole.shape === "circle")).toBe(true)
+})
+
+test("SPDIP aliases and default builder produce the same 28-pin footprint", () => {
+  const expected = fp().spdip(28).circuitJson()
+  for (const name of ["spdip", "spdip28", "SPDIP28", "SPDIP-28", "spdip-28"]) {
+    expect(fp.string(name).circuitJson()).toEqual(expected)
+  }
+  expect(fp().spdip().circuitJson()).toEqual(expected)
+  expect(getFootprintNames()).toContain("spdip")
+})
+
+test("SPDIP preserves DIP geometry and supports explicit drill and pad sizes", () => {
+  expect(fp.string("SPDIP-28_id1mm_od1.8mm").circuitJson()).toEqual(
+    fp.string("dip28_w7.62mm_p2.54mm_id1mm_od1.8mm").circuitJson(),
+  )
+  expect(fp.string("spdip28").json()).toMatchObject({
+    fn: "spdip",
+    num_pins: 28,
+    w: 7.62,
+    p: 2.54,
+    id: 0.8,
+    od: 1.6,
+  })
+})
+
+test("SPDIP global modifiers retain pin-one relocation and omit silkscreen", () => {
+  expect(
+    fp
+      .string("SPDIP-28_pin1location(leftside,bottom)_nosilkscreen")
+      .circuitJson(),
+  ).toEqual(
+    fp.string("dip28_pin1location(leftside,bottom)_nosilkscreen").circuitJson(),
+  )
+})
+
+test("spdip28", () => {
+  expect(
+    convertCircuitJsonToPcbSvg(fp.string("SPDIP-28").circuitJson()),
+  ).toMatchSvgSnapshot(import.meta.path, "spdip28")
+})
+
+test("spdip28_custom_drill", () => {
+  expect(
+    convertCircuitJsonToPcbSvg(
+      fp.string("spdip28_id1mm_od1.8mm").circuitJson(),
+    ),
+  ).toMatchSvgSnapshot(import.meta.path, "spdip28_custom_drill")
+})