pdf-page/gpt-5.6-sol / tier-4-gp2y0a21yk

```openscad
$fn = 64;

// GP2Y0A21YK0F external model
// Units: mm
// Origin: center of the lens-case footprint
// +Z: optical/lens direction, +Y: forward

case_x            = 29.5;
case_y            = 13.0;
case_h            = 6.3;

mount_pitch       = 37.0;
mount_lobe_r      = 3.75;
mount_hole_d      = 3.2;
mount_plate_h     = 1.2;

bar_w             = 10.1;
overall_y         = 18.9;
bar_rear_y        = -(overall_y - case_y / 2);

cable_notch_w     = 5.4;
cable_notch_depth = 3.2;

emitter_x         = -case_x / 2 + 4.5;
detector_x        = emitter_x + 20.0;

lens_outer_d      = 8.4;
lens_clear_d      = 7.2;
lens_projection   = 2.0;

module rounded_rect_2d(size = [10, 10], r = 1) {
    hull() {
        for (x = [-size[0] / 2 + r, size[0] / 2 - r])
            for (y = [-size[1] / 2 + r, size[1] / 2 - r])
                translate([x, y])
                    circle(r = r);
    }
}

module rounded_box(size = [10, 10, 10], r = 1) {
    linear_extrude(height = size[2])
        rounded_rect_2d([size[0], size[1]], r);
}

module mounting_bar_2d() {
    difference() {
        union() {
            // Plate below the main lens case
            square([case_x, case_y], center = true);

            // Tapered links to the mounting-hole lobes
            polygon([
                [-case_x / 2, -3.1],
                [-mount_pitch / 2, -mount_lobe_r],
                [-mount_pitch / 2,  mount_lobe_r],
                [-case_x / 2,  3.1]
            ]);

            polygon([
                [ case_x / 2, -3.1],
                [ mount_pitch / 2, -mount_lobe_r],
                [ mount_pitch / 2,  mount_lobe_r],
                [ case_x / 2,  3.1]
            ]);

            // Two mounting-hole lobes
            translate([-mount_pitch / 2, 0])
                circle(r = mount_lobe_r);

            translate([mount_pitch / 2, 0])
                circle(r = mount_lobe_r);

            // Downward connecting bar / cable outlet
            polygon([
                [-6.2, -case_y / 2],
                [ 6.2, -case_y / 2],
                [ bar_w / 2, bar_rear_y],
                [-bar_w / 2, bar_rear_y]
            ]);
        }

        // Mounting holes, diameter 3.2
        translate([-mount_pitch / 2, 0])
            circle(d = mount_hole_d);

        translate([mount_pitch / 2, 0])
            circle(d = mount_hole_d);

        // U-shaped cable outlet notch
        translate([
            -cable_notch_w / 2,
            bar_rear_y - 0.1
        ])
            square([
                cable_notch_w,
                cable_notch_depth + 0.1
            ]);
    }
}

module mounting_bar() {
    color([0.10, 0.10, 0.11])
        linear_extrude(height = mount_plate_h)
            mounting_bar_2d();
}

module lens_case() {
    color([0.12, 0.12, 0.13])
        difference() {
            translate([0, 0, mount_plate_h - 0.02])
                rounded_box(
                    [case_x, case_y, case_h - mount_plate_h + 0.02],
                    0.7
                );

            // Shallow recess around circular emitter window
            translate([emitter_x, 0, case_h - 0.35])
                cylinder(d = lens_outer_d + 0.7, h = 0.5);

            // Shallow recess around rectangular detector window
            translate([detector_x, 0, case_h - 0.35])
                linear_extrude(height = 0.5)
                    rounded_rect_2d([9.0, 8.4], 0.8);
        }

    // Raised rim around emitter
    color([0.06, 0.06, 0.065])
        translate([emitter_x, 0, case_h - 0.05])
            difference() {
                cylinder(d = lens_outer_d, h = 0.65);
                translate([0, 0, -0.1])
                    cylinder(d = lens_clear_d, h = 0.9);
            }

    // Raised rim around detector
    color([0.06, 0.06, 0.065])
        translate([detector_x, 0, case_h - 0.05])
            linear_extrude(height = 0.65)
                difference() {
                    rounded_rect_2d([9.0, 8.4], 0.8);
                    rounded_rect_2d([7.4, 6.8], 0.65);
                }
}

module lenses() {
    // Light emitter: circular acrylic lens
    color([0.60, 0.72, 0.74, 0.82])
        translate([emitter_x, 0, case_h])
            union() {
                cylinder(
                    d1 = lens_clear_d,
                    d2 = lens_clear_d - 0.8,
                    h = lens_projection * 0.65
                );

                translate([0, 0, lens_projection * 0.65])
                    scale([1, 1, 0.35])
                        sphere(d = lens_clear_d - 0.8);
            }

    // Light detector: rectangular optical window
    color([0.27, 0.34, 0.36, 0.88])
        translate([detector_x, 0, case_h])
            union() {
                linear_extrude(height = lens_projection * 0.70)
                    rounded_rect_2d([7.4, 6.8], 0.65);

                translate([0, 0, lens_projection * 0.70])
                    scale([1, 0.85, 0.28])
                        sphere(d = 6.6);
            }
}

module cables() {
    cable_start_y = bar_rear_y + cable_notch_depth;
    cable_length  = 25;
    cable_d       = 1.1;

    cable_colors = [
        [0.72, 0.12, 0.10],
        [0.08, 0.08, 0.08],
        [0.92, 0.92, 0.90]
    ];

    for (i = [-1 : 1]) {
        color(cable_colors[i + 1])
            translate([
                i * 1.45,
                cable_start_y,
                mount_plate_h / 2
            ])
                rotate([90, 0, 0])
                    cylinder(d = cable_d, h = cable_length);
    }

    // Simple strain-relief section
    color([0.16, 0.16, 0.17])
        translate([0, cable_start_y - 1.6, mount_plate_h / 2])
            rotate([90, 0, 0])
                cylinder(d = 4.8, h = 4.0);
}

union() {
    mounting_bar();
    lens_case();
    lenses();
    cables();
}
```