rushabhcodes/ESP32-E-Reader

scripts/check-display-connection.py

"""Check the installed display GLB against routed PCB/component and case CAD.

Run after export: blender --background --python-exit-code 1 --python
scripts/check-display-connection.py -- dist/index/assembly.glb
This checks nominal meshes; the delivered flex construction remains unverified.
"""

import json
from pathlib import Path
import sys
from math import pi
import bpy
import bmesh
from mathutils import Matrix, Vector
from importlib import import_module

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT / "scripts"))
display = import_module("display-flex")
SPEC = display.SPEC
INPUT = Path(sys.argv[sys.argv.index("--") + 1])
circuit = json.loads((ROOT / "dist/index/circuit.json").read_text())
sources = {item["name"]: item["source_component_id"] for item in circuit if item["type"] == "source_component"}
j2 = next(item for item in circuit if item["type"] == "cad_component" and item.get("source_component_id") == sources["J2"])
screen = next(item for item in circuit if item["type"] == "cad_component" and item.get("source_component_id") == sources["EPD1"])
assert j2["position"] == screen["position"], "Screen must follow the actual J2 CAD anchor"
assert abs(j2["position"]["x"] - SPEC["connector"]["centerX"]) < 1e-6
assert abs(j2["position"]["y"] - SPEC["connector"]["centerY"]) < 1e-6
assert abs(j2["position"]["z"] - SPEC["connector"]["boardSurfaceZ"]) < 1e-6
assert j2["rotation"]["z"] == 0
assert screen["rotation"]["z"] == SPEC["connector"]["screenCadRotationZ"]


def intersection(a, b):
    bounds = []
    for obj in (a, b):
        points = [obj.matrix_world @ Vector(p) for p in obj.bound_box]
        bounds.append([(min(p[i] for p in points), max(p[i] for p in points)) for i in range(3)])
    if any(min(x[1], y[1]) <= max(x[0], y[0]) for x, y in zip(*bounds)):
        return 0.0
    test = a.copy()
    test.data = a.data.copy()
    bpy.context.collection.objects.link(test)
    bpy.context.view_layer.objects.active = test
    modifier = test.modifiers.new("overlap", "BOOLEAN")
    modifier.operation = "INTERSECT"
    modifier.solver = "EXACT"
    modifier.object = b
    bpy.ops.object.modifier_apply(modifier=modifier.name)
    mesh = bmesh.new()
    mesh.from_mesh(test.data)
    value = abs(mesh.calc_volume(signed=True))
    mesh.free()
    if value > 1e-5:
        points = [test.matrix_world @ v.co for v in test.data.vertices]
        print("Intersection region:", a.name, b.name,
              [[round(min(p[i] for p in points), 5), round(max(p[i] for p in points), 5)] for i in range(3)], flush=True)
    bpy.data.objects.remove(test, do_unlink=True)
    return round(value, 6)


def prism(name, points, low, high):
    n = len(points)
    verts = [(p["x"], p["y"], z) for z in (low, high) for p in points]
    faces = [tuple(reversed(range(n))), tuple(range(n, 2 * n))]
    faces += [(i, (i + 1) % n, (i + 1) % n + n, i + n) for i in range(n)]
    mesh = bpy.data.meshes.new(name)
    mesh.from_pydata(verts, [], faces)
    mesh.update()
    obj = bpy.data.objects.new(name, mesh)
    bpy.context.collection.objects.link(obj)
    bm = bmesh.new()
    bm.from_mesh(mesh)
    bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces))
    bm.to_mesh(mesh)
    bm.free()
    return obj


bpy.ops.object.select_all(action="SELECT")
bpy.ops.object.delete(use_global=False)
before = set(bpy.data.objects)
bpy.ops.import_scene.gltf(filepath=str(ROOT / "assets/enclosure/display-panel.glb"))
parts = [obj for obj in set(bpy.data.objects) - before if obj.type == "MESH"]
for obj in parts:
    obj.matrix_world = Matrix.Translation(Vector(tuple(screen["position"][key] for key in ("x", "y", "z")))) @ Matrix.Rotation(screen["rotation"]["z"]*pi/180,4,"Z") @ Matrix.Rotation(-pi / 2, 4, "X") @ obj.matrix_world
panel = next(obj for obj in parts if "nominal-outline" in obj.name)
flex = next(obj for obj in parts if "flex-polyimide" in obj.name)
stiffener = next(obj for obj in parts if "stiffener" in obj.name)
contacts = [obj for obj in parts if "EPD-contact-" in obj.name]
assert len(contacts) == 24, "Missing mating contacts"
panel_points = [panel.matrix_world @ v.co for v in panel.data.vertices]
assert abs(min(p.z for p in panel_points) - SPEC["panel"]["frontZ"]) < 1e-5
assert abs(max(p.z for p in panel_points) - SPEC["panel"]["backZ"]) < 1e-5
path = display.flex_path()
from math import hypot
length = sum(hypot(b[0] - a[0], b[1] - a[1]) for a, b in zip(path, path[1:]))
assert abs(length - SPEC["flex"]["nominalTailLength"]) < SPEC["flex"]["tailLengthTolerance"]
assert abs(max((stiffener.matrix_world @ v.co).y for v in stiffener.data.vertices) - path[-1][0]) < 1e-5
assert all(max((obj.matrix_world @ v.co).z for v in obj.data.vertices) < SPEC["flex"]["entryZ"] for obj in contacts), "The installed tail exposes contacts toward -Z"
for obj in contacts:
    pin = int(obj.name.rsplit("-", 1)[1])
    source_port = next(item for item in circuit if item["type"] == "source_port" and item.get("source_component_id") == sources["J2"] and item.get("pin_number") == pin)
    pcb_port = next(item for item in circuit if item["type"] == "pcb_port" and item.get("source_port_id") == source_port["source_port_id"])
    points = [obj.matrix_world @ v.co for v in obj.data.vertices]
    assert abs((max(p.x for p in points) + min(p.x for p in points)) / 2 - pcb_port["x"]) < .02, f"Contact {pin} reversed or offset"

# Use a conservative solid FR-4 outline. Small component locator cutouts are
# filled in this ribbon test; removing them could only increase clearance.
board = next(item for item in circuit if item["type"] == "pcb_board")
pcb = prism("actual-PCB-outline", board["outline"], -board["thickness"] / 2, board["thickness"] / 2)
assert all(item.get("pcb_component_id") for item in circuit if item["type"] == "pcb_cutout"), "Edge-wrap revision must not retain a board-level display slot"
assert SPEC["route"]["bendCenterY"] < min(p["y"] for p in board["outline"]), "Bend must be outside PCB"
obstacles = [pcb]
for name in ["front-chassis", "rear-cover", "battery-envelope-DO-NOT-PRINT"]:
    bpy.ops.wm.stl_import(filepath=str(ROOT / "assets/enclosure/stl" / (name + ".stl")))
    obj = bpy.context.object
    obj.name = name
    obstacles.append(obj)

before = set(bpy.data.objects)
bpy.ops.import_scene.gltf(filepath=str(INPUT))
pcb_refs = {item["name"] for item in circuit if item["type"] == "source_component" and item["source_component_id"] in {e["source_component_id"] for e in circuit if e["type"] == "pcb_component"}}
conversion = Matrix(((-1, 0, 0, 0), (0, -1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1)))
components = []
for obj in set(bpy.data.objects) - before:
    if obj.type == "MESH" and obj.name in pcb_refs:
        obj.matrix_world = conversion @ obj.matrix_world
        components.append(obj)
connector = next(obj for obj in components if obj.name == "J2")
assert len(connector.data.vertices) > 100, "Missing real connector model"
obstacles += [obj for obj in components if obj != connector]
overlaps = {part.name: {obj.name: value for obj in obstacles if (value := intersection(part, obj)) > 1e-5} for part in (panel, flex, stiffener)}
# Insulating ribbon and stiffener must fit the modeled mating cavity. The
# exposed conductive contact faces intentionally mate with socket contacts.
connector_overlaps = {part.name: intersection(part, connector) for part in (flex, stiffener)}
report = {"nominal_installed_length_mm": round(length, 6), "nominal_tail_length_mm": SPEC["flex"]["nominalTailLength"], "bend_radius_mm": SPEC["flex"]["bendRadius"], "modeled_contacts": len(contacts), "contact_face": "bottom (-Z)", "route": SPEC["route"], "connector_center_y_mm": j2["position"]["y"], "solid_overlaps_mm3": overlaps, "connector_insulation_overlaps_mm3": connector_overlaps, "basis": SPEC["basis"]}
report["scope"] = "Nominal mesh clearance only. Run check-display-interface.py separately: CAD overlap success does not establish real panel-tail compatibility."
(ROOT / "assets/enclosure/stl/display-connection-check.json").write_text(json.dumps(report, indent=2) + "\n")
print(json.dumps(report, indent=2))
assert not any(overlaps.values()), "Display assembly collision"
assert not any(value > 1e-5 for value in connector_overlaps.values()), "Ribbon does not fit the connector cavity"