MeshCore/docs/carrier_wave_validation.md

CW and CW2 validation

Tested on the MercerWoodMesh lab Pi on September 14, 2026 (Pacific), using base commit 9241ccc253ad2f8ac2c9a2fe756f59ba2f52505d plus the CW changes. Test images are marked v1.17.1.6-cw-test-9241ccc2; they are development images.

A separate RAK4631 sampled instantaneous RSSI every approximately 10 ms. The transmitting boards ran the Full V4 repeater and Full T1000-E Companion builds. Both were configured for −9 dBm chip TX power, with profiles at 909.5 and 919.5 MHz, BW125, SF7, CR5, and 32-symbol preambles.

Check	V4 / SX1262	T1000-E / LR1110
cw on 0.25 measured duration	0.25 s	0.25 s
cw on 1.25 measured duration	1.25 s	1.25 s
Manual stop approximately 1 s into a 5 s request	1.01 s	1.01 s
cw on 1.25 after enabling RXPS	1.26 s	1.25 s
cw2 on 1.25 on the second frequency	1.25 s	1.25 s
Primary-frequency RSSI change while CW2 transmits	0 dB	0 dB
Paired RX and TX recovery checks	5/5 passed	5/5 passed

The observer saw roughly −56 to −57 dBm during V4 carriers and −67 to −71 dBm during T1000-E carriers, against a −112 to −113 dBm baseline. Readings returned to baseline after timeout and manual stop. These are received signal readings, not calibrated transmitter output measurements.

RX recovery used CRC-valid LoRa test payloads and the DUT's receive counter. TX recovery used each DUT's MeshCore advertisement, received with valid CRC by the observer. Both DUTs finished in RX, with CW and radio2 disabled and no outbound packet pending. The observer has no autonomous transmission.

Software checks

• 1,436 native tests passed, including new checks that CW holds queued packets, services its deadline, and prevents transmission in the same loop where a received command starts CW.
• Compiled production-method tests cover fractional input, malformed durations, bounds, timer rollover, busy/IRQ rejection, RXPS cleanup, board TX/RX callbacks, profile selection and replacement, failed TX entry, stop retries, and failed RX restart. An ESP32 sleep test covers a carrier with USB disconnected.
• Full V4 repeater, Full T1000-E Companion, and ordinary STM32 RAK_3x72_companion_radio_usb builds passed. The STM32 build is a compilation check, not an RF test of that board.
• An additional existing OTA sleep test still expects the old ota::ota_ctx().apply_pending spelling. It fails against unchanged HEAD src/Mesh.cpp and test-file contents; the actual implementation uses ota_context_if_active(). This is separate from the CW changes.

Bench qualifications

The first CW2 request arrived before radio2's existing delayed activation. The harness now polls get radio2.status for the active mode before testing.

An initial V4 dual-profile packet probe used a 120-symbol preamble against 32-symbol profiles. A comparison around another CW2 burst received 0/8 before and 1/8 afterward with that mismatched probe, versus 8/8 before and 8/8 afterward with a matching 32-symbol probe. The configured preamble also sets the driver's preamble-detection hold timeout, so a much longer incoming preamble can outlast that hold and be interrupted by scanning. The final dual-profile recovery checks use matched preambles. This finding does not establish general packet-loss performance for every scan combination.

These checks establish RF activity, selected-frequency behavior, and recovery on the tested boards. They do not measure spectral purity, frequency error, SWR, calibrated power, or months of uptime. Carrier timeouts are serviced by the main loop and depend on that loop remaining responsive.

Reproduction

Append tools/hil/cw_observer.ini to extra_configs in platformio.local.ini, preserving existing entries, and build pio run -e cw_observer_rak4631. Flash that application onto a separate lab RAK4631. Do not run PlatformIO concurrently with another build or upload in the checkout.

Configure the lab DUT's primary profile as above, disable radio2, set TX power to −9 dBm, and reboot to apply saved primary settings. Then run:

python3 tools/hil/carrier_wave.py --dut /dev/serial/by-id/DUT \
  --observer /dev/serial/by-id/OBSERVER --role repeater --output cw-results.json

Use --role companion for the T1000-E. The harness changes lab radio2/RXPS settings and emits short RF bursts and packet probes. It is for test boards.

Compact evidence: carrier_wave_results.json. Command guide: carrier-wave RF checks.