LED Matrix Panel, 2U

A 2U panel for our 10-inch rack carrying one or two 8x8 WS2812 LED matrices behind a translucent diffuser. Two units because the module is 65 mm square and a rack unit is 44.45.

Held by its envelope, not its holes. The cheap 8x8 matrices everybody actually buys either have no mounting holes at all or put them within a millimetre of the lit field — we measured it: a clearance hole at the module’s own corner would overlap the window, so there is no panel that both shows the LEDs and bolts to the PCB. Instead a retainer frame behind the panel captures the module by its edges. Anything 65 mm square fits, whatever its board is drilled for.

The diffuser is the point. Bare WS2812s are point sources and read as 64 dazzling dots rather than a picture. Ours prints in translucent filament and is trapped between the panel and the module — wider than the window so it cannot fall through, narrower than the module so the module holds it in. No fixings of its own. Pick its colour, or leave it off.

Prints in two tiles. A 254 x 88.9 mm face needs 242.5 mm of a 224 mm bed, so it is cut and lapped like our 2U fan panel, with a pair of M3 bolts clamping the joint through a solid rib. With two matrices the seam runs between them; with one, the matrix takes the middle and the seam moves aside.

In the box: both tiles, a retainer frame and diffuser per module, and every M3 screw and nut — for the modules and for the seam. You supply the matrices: a dozen makes, all cheaper than this panel.

Choose: one or two matrices, diffuser and its colour, and how much the unused face is lightened.