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BENCH-CAMC2 — end-to-end LoRaCam C2 round-trip (two boards)

Goal: prove a real encrypted, signed, whitelisted command goes from a commander board to the cam board over LoRa, the cam acts on it, and ACKs back — on your bench.

What you need

  • Board A = the cam — the XIAO ESP32-S3 Sense + the Wio you already wired. On COM14.
  • Board B = the commander — a SECOND XIAO + a Wio, wired the SAME way (SPI on D8/D9/D10, NSS→D4 / BUSY→D3 / RST→D2 / DIO1→D1, 3V3, GND). A repeater board works as-is (its R2 is that exact radio). No camera needed on board B.

Both boards already share a throwaway bench key and fixed IDs (cam = 0xCA00, commander = 0xC0DE), baked into the build flags — so they whitelist each other with no manual key entry.

Steps (one at a time)

1. Flash the cam (board A, COM14) — already done for you:

pio run -e bench_camc2 -t erase  --upload-port COM14
pio run -e bench_camc2 -t upload --upload-port COM14

Boot log should show: [CamC2Config] bench-seeded peer 0x0000c0de and [Radio2-Edge] ready ... sync 0x33.

2. Flash the commander (board B). Find its port (e.g. COM13), then:

pio run -e bench_camc2_cmdr -t erase  --upload-port COM13
pio run -e bench_camc2_cmdr -t upload --upload-port COM13

3. Open BOTH serial monitors (two terminals):

pio device monitor --port COM14      ← the cam
pio device monitor --port COM13      ← the commander

4. Wait ~6 seconds after the commander boots (it has a 5 s "press BOOT for portal" window first).

5. In the COMMANDER monitor, type one key (just press the letter — no Enter needed):

  • g = get status · s = snap photo · r = record 30 s · x = stop

6. What you should see — the round-trip:

Commander:

evt=C2TX radio=1 to=0x0000ca00 cmd=6 seq=1
evt=C2RX radio=1 from=0x0000ca00 type=2 seq=1 len=9      ← the cam's signed ACK

Cam (COM14):

evt=C2CMD radio=1 from=0x0000c0de cmd=6 seq=1 res=0      ← authenticated + executed (res=0 = OK)
[CamC2] (stub) ...                                       ← Phase-1 stub; real camera lands in Phase 2

res=0 = the command was accepted (valid signature, in-whitelist, fresh seq) and run. The camera actions are stubs for now (stub.jpg) — Phase 2 wires the real OV2640/SD.

Quick checks it's really secure (optional)

  • Wrong key rejected: flash board B with a different BRIDGE_C2_PEER_KEY (edit the env) → the cam logs [CamC2] drop ... reason=bad-mic and does NOT execute.
  • Replay rejected: every command uses a new seq, so re-sends are new. To force a replay, capture a frame and resend it (see the offline tool) → cam logs evt=C2DROP ... reason=replay.

Offline frame tool (no hardware)

tools/cam-c2.py builds/verifies frames with the same crypto as the firmware:

python tools/cam-c2.py selftest                                  # crypto KAT
python tools/cam-c2.py gen 000102030405060708090a0b0c0d0e0f 1 0000C0DE 0000CA00 1 06   # a GET_STATUS cmd
python tools/cam-c2.py verify <frame-hex> 000102030405060708090a0b0c0d0e0f             # decode/verify

Use verify on a frame captured by a sniffer to confirm what's on air, byte-for-byte.

Notes

  • Both boards are on the same C2 channel: Custom sync 0x33, 906.875 MHz, BW250, SF9 (build defaults).
  • The bench key/IDs are throwaway — never a real deployment key.
  • These are bench envs (BRIDGE_BENCH_AUTOSAVE, fixed IDs, build-flag key); the shipping xiao_loracam build uses MAC-derived IDs and portal/serial provisioning (Phase 3), and stays do-no-harm.