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How Wi-Fi Works for Agri Sensors
HPzenAi AGRI-SOIL-8F sensors communicate with the HPzenAi IoT gateway over RS485 Modbus RTU — a wired protocol designed for long field cable runs. The gateway handles the Wi-Fi connection to your router or mobile hotspot and forwards all soil data to the HPzenAi cloud. The sensor itself has no Wi-Fi radio; it relies entirely on the gateway for cloud connectivity. Complete the gateway Wi-Fi setup before commissioning any soil sensors on the RS485 bus.
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Step 1 — Complete Gateway Wi-Fi Setup
- 1Set up the gateway Wi-Fi first — see IoT Gateway → Wi-Fi Setup Guide for the full walkthrough.
- 2Confirm the gateway LED is solid green, indicating a stable Wi-Fi and cloud connection.
- 3Open the HPzenAi app and verify the gateway shows Online status before proceeding.
- 4For remote or off-grid field sites, choose a gateway model with SIM/4G connectivity instead of Wi-Fi.
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Step 2 — Wire the Sensor to the Gateway
- 1Connect the sensor junction box RS485 A terminal to the gateway RS485 A terminal using shielded cable.
- 2Connect the sensor junction box RS485 B terminal to the gateway RS485 B terminal.
- 3Apply 12V DC power to the sensor junction box.
- 4The gateway will auto-discover the sensor within 60 seconds of power-on if RS485 wiring is correct.
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Step 3 — Link the Sensor in the App
- 1Open the HPzenAi app and navigate to Gateway → RS485 Scan.
- 2Wait for the scan to complete — the soil sensor will appear with its Modbus address.
- 3Tap the detected sensor and select Link to add it to your device list.
- 4The sensor tile will display live soil parameters: moisture, temperature, EC, pH, N, P, K, and salinity.
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Step 4 — Configure Irrigation Triggers
- 1Open the soil sensor tile and tap Settings.
- 2Set moisture low threshold for irrigation trigger — e.g., alert when moisture drops below 30%.
- 3Set EC and pH alert thresholds appropriate for your crop and soil type.
- 4Link the sensor to a relay controller for automatic irrigation control: Relay → Automation → Source Sensor.
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Gateway Wi-Fi Quality Requirements
- 1Minimum signal: −75 dBm at the gateway location for stable cloud sync.
- 2For large farms, position the gateway centrally with a directional antenna toward the field enclosure.
- 3Use a SIM/4G gateway model for remote paddocks where Wi-Fi infrastructure does not reach.
- 4Soil sensor readings buffer locally on the gateway for up to 24 hours if cloud connectivity is lost — data uploads automatically on reconnection.