ESP32 gateway, LoRa nodes and industrial motor control
The hardware direction converges on an ESP32-based gateway/controller family, LoRa for farm-wide communication, and integration with existing motor starter infrastructure rather than replacing it.
One coordinator per farm or logical farm cluster
Central farm controller: LoRa coordination, cellular/cloud bridge and local fallback.
- ESP32/ESP32-S3 class MCU as the main embedded compute platform
- LoRa transceiver for farm-wide field communications
- 4G/cellular modem for cloud backhaul where available
- Optional GPS where farm/device location is required
- Local non-volatile configuration and offline command/event buffering
- Secure device identity, provisioning and firmware-update mechanism
- Watchdog, brownout handling and deterministic recovery
- Maintains enough local state for safe operation during internet outages
Nodes at each motor/aerator control panel
Secondary devices operate the motor/aerator control interface and report status back to the gateway.
- Microcontroller board with LoRa connectivity
- Digital output/control interface suitable for the existing starter/contactor arrangement
- Input/status interface for commanded/observed state, subject to final electrical sensing design
- Local fail-safe: communication loss must never create an unsafe motor state
- Unique device identity and pairing credentials
- 01New secondary controller enters provisioning mode
- 02Gateway authorises a pairing session
- 03Secondary sends its unique device identity
- 04Gateway assigns farm/network/node identity and credentials
- 05Both sides persist the pairing record
- 06After reboot or power loss the device reconnects using stored credentials
- 07Invalid credentials or farm transfer requires controlled re-provisioning
Long-range field communication, deliberately scheduled
433 MHz and higher-frequency options were considered. The final frequency must be selected according to deployment-country spectrum rules, antenna design, required range, interference environment and radio certification.
- One primary gateway per farm or logical farm cluster
- Multiple secondary nodes distributed around ponds and motor panels
- Unique node IDs and network/application keys
- Explicit acknowledgements for critical control commands
- Sequence numbers or message IDs to prevent duplicate execution
- Retry/backoff with bounded retries; heartbeat at a controlled interval
Long range does not eliminate collisions. Multiple devices on the same LoRa network require a deliberate MAC/application strategy.
- Controlled transmissions rather than free-running chatter
- Randomised backoff for asynchronous events
- Compact payloads and acknowledgement only where needed
- Gateway-side de-duplication and replay protection
- Offline queueing when the uplink is unavailable
Command the industrial power stage — never replace it
The secondary controller should not directly switch a large motor load.
The DOL starter/contactor, overload protection and associated electrical protection remain responsible for the motor power circuit. For farms that need all aerators to operate together, a group ON/OFF strategy can be implemented, but the exact contactor and protection arrangement must be validated against actual motor ratings and site wiring.
An ON command is not proof that the motor is actually running. Future electrical telemetry closes that observability gap; until then the backend distinguishes commanded state from measured state.