Gateways overview
A gateway is the thing in your building that reads local sensors (RS485/Modbus, GPIO, I²C, SPI, UART, CAN, M-Bus) and forwards their readings to Synacl over MQTT.
Two kinds of gateway:
- An ESP32 running the Synacl gateway firmware — flashed from the browser, updated over the air, no code to write.
- A software gateway — anything you build yourself that speaks the public gateway protocol: a Raspberry Pi, a PC, a PLC, a container. See connect your own gateway.
Lifecycle of an ESP32 gateway:
- Flash firmware onto the board (flash an ESP32).
- Provision it with Wi-Fi so it registers itself (provision Wi-Fi).
- Add devices under it and pick sensors/pins (sensor pick & pin validation).
- Maintain it — OTA updates, restart, reset config, or view its console log over USB.
Each gateway reports online, signal strength (rssi), and its last local IP.
Its status dot reflects only the gateway's own connection — two states: green (online) and red/grey (offline). An unreachable device does not turn the gateway amber: the gateway stays green and the unreachable device is flagged at the device level — an amber device-count on the gateway card, a "N device(s) unreachable" badge on the gateway page, and an amber dot on the device itself. This keeps a down gateway and a misbehaving device clearly distinct. See device & gateway status.