DFRobot RS485 Waterproof Ambient Light Sensor (0-200,000 Lux) - IP68 Submersible, Modbus-RTU

Using standard CAT5e cable and proper termination, the RS485 interface supports reliable data transmission up to 1000 meters. For optimal performance over long distances, ensure correct bus termination (120Ω resistor) and use shielded, twisted-pair cable to minimize electromagnetic interference.

Yes, the sensor's wide 5-32V DC input range includes the standard 5V logic from an Arduino. However, note that the RS485 interface operates at logic levels and requires a separate TTL-to-RS485 converter module (like a MAX485) to communicate with a microcontroller's UART. The sensor itself does not output TTL signals directly.

The IP68 rating indicates protection against continuous immersion in water under specified conditions (typically depth and time defined by the manufacturer, often 1 meter for 30 minutes). It is designed for harsh environments like rain, irrigation splash, or temporary flooding, making it ideal for outdoor and agricultural applications, but verify specific depth/duration limits for permanent underwater installation.

The sensor uses standard Modbus-RTU holding registers to output data. Typically, the measured Lux value is stored in a 16-bit or 32-bit register (consult the specific product datasheet for the exact register address). You can read this register using function code 0x03 (Read Holding Registers) from any Modbus master, such as a PLC, Raspberry Pi with libmodbus, or Arduino with a Modbus library.