Waleed — Adom Molecule LED Nameplate

{
  "_meta": {
    "circuit_json_sha256": "2b311b2f9345267b08c2bef868389c9bcdca4695be70328781f1252c6a3a549e",
    "do_not_edit_by_hand": "steps are authored in scripts/gen-walkthrough.py; _meta (incl. circuit_json_sha256) comes from `adom-tsci walkthrough-gen` so staleness detection still works. Re-run scripts/gen-walkthrough.py after changing the board.",
    "generated_at": "2026-08-07T12:47:19.298746478+00:00",
    "generated_by": "adom-tsci walkthrough-gen",
    "package_name": "waleed-nameplate",
    "project_name": "waleed-nameplate",
    "steps_authored_by": "scripts/gen-walkthrough.py"
  },
  "steps": [
    {
      "id": "intro",
      "minMs": 7000,
      "title": "Waleed: the name is the ground plane",
      "focus": {
        "kind": "all"
      },
      "highlight": [],
      "text": "A 236 x 76 mm Adom molecule. The gold letters are not silkscreen and not letter-shaped copper: they are 390 openings in the soldermask over one solid rectangular ground pour, so what you are looking at is bare plated copper at the bottom of a 194 x 40 mm window."
    },
    {
      "id": "ground-path",
      "minMs": 8000,
      "title": "Every LED returns through the letters",
      "focus": {
        "kind": "all"
      },
      "highlight": [],
      "text": "The top layer carries exactly one ground pour and there is no ground pour on the bottom, so there is no second return path. Current leaves an LED cathode, crosses the copper the name is cut into, and only then reaches the connector. The claim that the name is part of the circuit is enforced by geometry, not by wiring convention."
    },
    {
      "id": "machine-pins",
      "minMs": 8000,
      "title": "Corner machine pins on the 32 mm scaffold grid",
      "focus": {
        "kind": "component",
        "name": "MP1",
        "zoomTight": true
      },
      "highlight": [
        "MP1",
        "MP2",
        "MP3",
        "MP4"
      ],
      "text": "Four large machine pins, one per corner, spanning 224 x 64 mm. Both spans are exact multiples of 32 mm, the base scaffold's large-contact pitch, so this drops straight onto the 18 x 18 contact field. A 3.6 mm pin body presses into a 3.45 mm plated hole: 0.15 mm of interference, solderless. The workcell pincers grip these to pick the molecule up. MP1 and MP4 are ground, MP2 and MP3 are +5 V, so the plate can also run off a control panel."
    },
    {
      "id": "leds",
      "minMs": 8000,
      "title": "14 side-view LEDs, firing inward",
      "focus": {
        "kind": "component",
        "name": "D1",
        "zoomTight": true
      },
      "highlight": [
        "D1",
        "D2",
        "D3",
        "D4",
        "D5",
        "D6",
        "D7",
        "D8",
        "D9",
        "D10",
        "D11",
        "D12",
        "D13",
        "D14"
      ],
      "text": "These are side-view parts, not ordinary chip LEDs. The die sits on its side behind a window in the long face of the package, so the beam leaves parallel to the board about 0.5 mm above the soldermask. Ringed around the edge facing inward, the light rakes across the plate at a grazing angle and washes the letters instead of escaping upward. A top-view LED here would light nothing."
    },
    {
      "id": "usbc",
      "minMs": 7000,
      "title": "USB-C power input",
      "focus": {
        "kind": "component",
        "name": "J1",
        "zoomTight": true
      },
      "highlight": [
        "J1"
      ],
      "text": "TYPE-C-31-M-12 on the east edge, shell just proud of the board edge so a plug can seat, with all four plated anchors under the shell rather than behind it. R_CC1 and R_CC2 are the Rd pulldowns on CC1 and CC2: without them a charger never enables VBUS and the board stays dark."
    },
    {
      "id": "current",
      "minMs": 7000,
      "title": "Each string: 150 R, then a via to the back",
      "focus": {
        "kind": "component",
        "name": "R1",
        "zoomTight": true
      },
      "highlight": [
        "R1",
        "R2",
        "R3"
      ],
      "text": "Everything is on the top side because the line does single-sided placement. 5 V through 150 R into a 3.2 V LED gives 12 mA each, 168 mA for the board, which any phone charger supplies. The +5 V plane is on the bottom, so each resistor hands off to a via whose ring laps onto its pad."
    },
    {
      "id": "nets",
      "minMs": 8000,
      "title": "X-ray the copper",
      "focus": {
        "kind": "netsMode"
      },
      "highlight": [],
      "text": "Press T or use the Nets toolbar button. The substrate fades and the routed copper lifts out. The ground net is the interesting one: it is almost entirely pour rather than traces, which is the point. Ground pads bond to the plate by sitting inside it, so the autorouter never gets the chance to route a shortcut around the letters."
    },
    {
      "id": "outro",
      "minMs": 6000,
      "title": "Fabrication note",
      "focus": {
        "kind": "netsModeOff"
      },
      "highlight": [],
      "text": "Specify ENIG rather than HASL. The letters are a large area of deliberately bare copper and are the whole point of the board; HASL leaves that area lumpy and uneven, ENIG leaves it flat and mirror gold. A dark soldermask maximises the contrast."
    }
  ]
}