Panels and power

The firmware is made for the common indoor HUB75 panels with an E pin (1/32 scan). It drives one 64x64 panel, or a 128x64 display: one 128x64 panel or two 64x64 panels side by side. Other sizes, like 64x32, aren’t supported.

What the firmware expects

The display settings live in firmware/gameday-common.yaml and firmware/controllers/moonhub75.yaml:

Setting	Value
Panel size	64x64 pixels each
Chain	one row, one or two panels wide (HORIZONTAL)
Scan wiring	STANDARD_TWO_SCAN
Clock	20 MHz
Color depth	8 bits

Pixel pitch isn’t part of these settings, so a 64x64 panel is driven the same way whatever its pitch. The firmware drives a 128x64 panel the same way as two 64x64 panels in a row.

One panel or two

You have	Pick	What the board shows
One 64x64 panel	One 64x64 panel	Logos side by side, stacked scores
One 128x64 panel	One 128x64 panel	Logos at the edges, big scores, records and timeout pips in the middle
Two 64x64 panels side by side	One 128x64 panel (the same choice)	Same as one 128x64 panel

One firmware drives both layouts. You pick the layout in the DIY installer before you install, and you can change it later on the device page. See Panel sizes.

Chain two 64x64 panels

The firmware drives two panels as one chain. Wire the board to the input of the first panel, then run a ribbon cable from that panel’s output to the input of the second. Set them side by side in one row, 128 pixels wide and 64 tall.

Tip

If the two halves of the board show up in the wrong order, swap the two panels.

Change the layout

In the Setup card on the device page, click the picture that matches your panels. The panel saves the choice and restarts with the new layout. Nothing needs reflashing.

Factory Reset returns the layout to the build’s default. The one-panel build starts as one 64x64 panel. A board installed with the 128x64 choice switches to the one-panel build at its first update, so after a factory reset on that board, pick the 128x64 layout again.

Power

Power the panels from a 5 V supply rated for them. The panel’s listing gives the current it draws at full brightness; size the supply for the panel maker’s rating, and add up both panels if you chain two.

A new install starts at about half brightness (128 of 255). Change it with the Brightness setting on the device page.

Coming in the next release

A panel that restarts twice in a row because its power dipped, as on a phone charger or a supply too weak for it, holds its brightness low so it stays on. A small plug pulses in its top right corner, and every two minutes the bottom line says “Check power supply”, until you press Clear on the device page. A panel that runs hot dims itself a step at a time and says “Too warm, dimming” until it cools.

Ribbon cables and wiring checks

If part of the panel is dark or shows the wrong colors, reseat the ribbon cable at both ends first. R1, G1 and B1 carry the top half of the panel and R2, G2 and B2 the bottom half, so a problem in one half points at those three wires. If the whole panel flickers or the colors are off, try 5 V level shifters (see Boards).

To check every pixel, run the test screen described in What’s different. For other symptoms, see Troubleshooting.