Chapter 10

USB control plane

USB is the preferred control path for agents, scripted bring-up, and anyone who already has a cable on the bench. It does not require joining the local setup network, and it keeps working when Wi‑Fi is misconfigured or missing.

Connect the sign to a workstation with the product USB cable. The device appears as a serial control channel. Commands are short, line-oriented requests; replies begin with a clear success or error marker so automated tools can ignore interleaved status noise.

What you can do

Health and status — confirm the sign is alive, see Wi‑Fi role, addresses, and current display mode. status panic reads the last crash breadcrumb; status clear exits safe-mode intent.
Home network join — set station credentials and associate without opening the SoftAP portal.
Display mode — switch the base preference between idle clock and launch countdown. display advance jumps to the next playlist slot when rotation is paused or you want a manual step.
Launch data — queue a live fetch when online, inspect last result and backoff, or inject a short offline list.
Notifications — show a timed overlay or clear the current one.
Wall time — set or confirm time when network sync has not yet arrived.
Visual check — request a compact panel snapshot for remote or automated inspection.
Settings — get, set, and save namespaced preferences (display brightness, night dim, eco sleep, timezone offset, accessibility preset, scene timing, SoftAP appearance). Export a JSON backup of non-secret keys; import restores those keys. Factory reset clears Wi‑Fi and preferences back to SoftAP-first defaults (requires an explicit confirm).

Who this chapter is for

Power users and agents who already operate hardware from a terminal. Casual owners can ignore USB entirely and use the on-device portal after joiningB0RD-<suffix>. Developer flash tools and image builds are outside this manual; see your organization’s release process.