LoRa: reaching an arcade by radio

Any arcade can run a LoRa gateway: a Meshtastic radio plugged into the arcade's machine, through which arcade T-Decks (LilyGO T-Deck and T-Deck Plus running the arcade firmware) reach the arcade with no internet of their own. A T-Deck signs in with its own key, sees its coins, sends, and reads and writes sealed messages; the gateway carries each request over LoRa and talks to the arcade the way a browser does.

Everything is on Admin → Meshtastic. The gateway is off until you turn it on.

1. Plug a Meshtastic radio (a Heltec V3, or any radio on stock Meshtastic firmware) into the arcade's machine by USB. 2. If the page says the radio support is missing, press Install the radio support at the node machine. It adds two Python packages, meshtastic and coincurve, to the arcade's own Python. 3. Pick the radio's serial port (/dev/ttyUSB0, /dev/ttyACM0, ...), give the gateway a name T-Decks will show, and tick the coins the T-Decks see. 4. Press Run the gateway.

The page then shows:

• The radio: its node id, region and preset, how many nodes it hears, and frames sent, acknowledged and failed.
• The T-Decks that have said hello: who is signed in, who is online, and mail waiting to go out to each.

The beacon is off by default. T-Decks find gateways by asking, and a beacon only adds airtime on a busy channel.

If the radio is unplugged or resets, the gateway opens it again by itself and keeps every T-Deck's session.

Linked arcades see a LoRa badge beside an arcade that runs a gateway, on Admin's overview.

Admin → Meshtastic → Flash a T-Deck writes the arcade firmware from the page over USB. It needs Chrome or Edge on a computer, which have Web Serial. The arcade fetches the firmware release and checks its sha256 before your browser writes it.

For the first flash, on a T-Deck still running stock Meshtastic:

1. Switch the T-Deck on. 2. Hold the trackball down, plug in the USB cable, and let go after 2 seconds. 3. Press Install the firmware and pick the T-Deck's port. 4. When it says done, unplug the T-Deck and plug it in again.

After the first flash, the T-Deck goes into flash mode by itself. Update only writes just the app part, which is faster.

The firmware is free software (GPL-3.0), built from Meshtastic's firmware and device-ui. Its source is at dogecoinarcade/firmware and dogecoinarcade/device-ui, branch arcade. The gateway is dogecoinarcade/arcade-lora.