masterETH firmware

Firmware for masterETH — the expanseElectronics network management box. A small ESP-07-based device that lives on the lighting LAN, automatically discovers expanseElectronics nodes (currently dualETH-PixelControl Gen5, firmware v7.3+), and exposes a single web UI for managing all of them in one place.

Hardware

Same dualETH PCB without the DMX driver IC / DMX connectors. ESP-07, W5500 Ethernet, single WS2812 status LED on GPIO 4. The DMX driver pins (GPIO 1, 2, 16) are unused on this variant.

Build / flash

PlatformIO project, single environment esp07:

pio run                     # compile
pio run -t upload           # serial upload
pio device monitor          # serial monitor at 115200

Same hard constraints as dualeth-pixelcontrol/ (160 MHz CPU, no <ESP8266WiFi.h>, no Ethernet.linkStatus() from inside an HTTP handler, web UI in PROGMEM rather than LittleFS). See dualeth-pixelcontrol/CLAUDE.md for the full rationale on each.

masterETH bumps MAX_SOCK_NUM in vendored lib/EthernetLarge from the upstream default of 2 to 4 — webServer + discovery UDP occupy 2 sockets continuously, and the outgoing identify probes need at least one more.

How discovery works

1. masterETH broadcasts an Art-Net ArtPoll (UDP 6454) every 5 s.
2. Each ArtPollReply is parsed for IP + MAC → registry entry (32-cap).
3. For each new IP, masterETH probes GET http://<ip>/api/identify. vendor: "expanseElectronics" → cache identity, mark compatible. 404 / wrong vendor / non-JSON → mark incompatible. Connect failure / timeout → leave as unknown (third-party Art-Net device or PC sender).
4. SPA polls /api/nodes every 5 s and re-renders.

REST API

See include/api.h.