DEVLOG #25

I measured and optimized the mmWave UDP transport, but the radar path still fails the lossless-transmission test (image 1).

The new firmware and server path use one UDP copy without artificial delay, disable Wi-Fi power saving on the mains-powered node, persist the collector target and CAD transform, and separate socket reads from processing. Reordering, sequence validation, deduplication, and rolling metrics expose failures instead of hiding them. Across three 60-second runs, unique arrivals improved by 11.2%, sequence loss fell from 20.6% to 13.1%, duplicates dropped to zero, and arrival P95 improved by 27.8%. Two copies did not reduce loss and only added duplicates, so one copy remains the default.

The transport is better, but not lossless: 13.1% sequence loss still blocks the radar preflight. The 50 ms interval is not the bottleneck; LD2450 frames arrive in bursts and the bridge emits about 2.64 measurements per second, not 20 independent frames per second. Next I will investigate RSSI and channel conditions, ARP and startup behaviour, Wi-Fi retries and airtime, and packet scheduling. RX/CSI stayed offline, so this is not a full Wi-Fi validation.

The server refactor from DEVLOG #24 is now integrated: routes, state, runtime, calibration, recording, model, and system responsibilities moved out of main.rs, with active, legacy, and unavailable-training contracts separated.

Desktop-interface removal remains in progress. Hardware-control modules are moving to a standalone control crate, while loopback-only browser server controls with origin checks are being added. Phase 1 calibration is also getting a longer measurement window and persisted evidence. RX3 currently lands roughly two to three metres from its expected fixed point. I will not consider the calibration valid until the transform, profile binding, or target association causing this offset is understood and corrected.

Next: resolve the RX3 Phase 1 offset (seen in image 2), then repeat the full fixed-point calibration and re-verify the radar preflight.