# firmware (Phase 1)

Embedded firmware for the single-device **3-in-1**: one Heltec WiFi LoRa 32 V3
(ESP32-S3 + one SX1262) time-multiplexing its single radio across the
Meshtastic / MeshCore / Reticulum PHY configs. See `../docs/ARCHITECTURE.md`
§2-§3 for why Phase 1 is a time-multiplexed single radio (Option A).

## Current increment: tri-protocol RX scanner

`src/main.cpp` is the **first** Phase 1 step. It does not bridge, decode, or
transmit yet — it rotates the SX1262 through each network's PHY preset, listens
for a fixed dwell window, and logs every raw LoRa packet it demodulates
(length, RSSI, SNR, hex). The point is to answer the project's central open
question before building any protocol stacks: *can one re-tuned radio actually
hear all three networks?*

**Validated on hardware (2026-07-01):** flashed to a Heltec V3, the scanner
`radio.begin()`'d cleanly, cycled all three presets, and received **live
Meshtastic broadcast packets** (payloads prefixed `ffffffff`) at −36 to
−41 dBm during the Meshtastic dwell. The single-radio time-multiplex premise
holds. MeshCore/Reticulum windows were silent — expected, see open items below.

## Open items baked into the config table

- **MeshCore sync word** (`src/main.cpp`, `CONFIGS[]`) is a guess (`0x12`,
  RadioLib's private default). Confirm against MeshCore `src/` — this is the
  same open item as `../docs/ARCHITECTURE.md` §1/§5.
- **Reticulum PHY** has no protocol-mandated preset; it's operator-configured.
  The entry is a placeholder — set it to your actual RNS RNode interface
  config or that window hears nothing.
- **Meshtastic frequency** is set to the documented 869.525 MHz, but Meshtastic
  hashes the channel name to a slot within the region plan, so real
  deployments may sit on a different slot.

## Build / flash / monitor

Requires PlatformIO (`pip install platformio`). Versions are pinned in
`platformio.ini` (espressif32 7.0.1, RadioLib 7.7.1) — do not float them.

```bash
pio run                                          # compile
pio run -t upload --upload-port /dev/cu.usbserial-0001   # flash (adjust port)
pio device monitor -b 115200                     # watch the scan
```

## Roadmap from here

1. **RX decode per protocol** — turn logged raw packets into `{sender, text}`
   (Meshtastic 16-byte header + AES-CTR; MeshCore framing; Reticulum via
   microReticulum). Start with Meshtastic since we already receive it.
2. **On-device bridge/dedup** — port the Phase 0 `bridge_core` relay+dedup
   logic to C++.
3. **TX** — re-originate a decoded message onto the other two networks within
   their dwell windows (queue between windows).
4. Revisit dwell timing / RAM budget with real per-protocol state (§3).