DFRobot RS485-to-UART Module with Active Isolation

The Gravity module from DFRobot converts the UART of a microcontroller such as Arduino or ESP32 to RS485 and galvanically isolates both signal and supply. The isolated side delivers 12 V with up to 2 W, so small RS485 sensors can be powered directly. The UART connector works with 3.3 V and 5 V. Protection against ESD up to 15 kV, bus driver short circuit and bus faults is built in, and a 120 Ω termination resistor can be switched on.

As a module without Gravity connector there is the Isolated RS485-TTL Converter Module.

Note: The connection cable can be converted to male pins with a Dupont cable M-M, so that it also fits an Arduino UNO.

Recommended Accessories:

• Ultrasonic 9-in-1 RS485 Weather Station Sensor for Arduino
• Ultrasonic 7-in-1 RS485 Weather Station Sensor for Arduino
• Dupont Cables M-M 10cm 20 Pieces

Features:

• Signal and supply isolation, isolation voltage 3000 V DC
• 12 V output, up to 2 W (about 160 mA) for RS485 devices
• 12V-IN input for an external 12 V supply
• Baud rate up to 1 Mbit/s
• Bus load 1/8 unit load, up to 256 nodes
• 120 Ω termination resistor with switch
• LEDs for TX and RX
• Gravity UART 4-pin: T, R, -, +
• RS485 screw terminals: 12V, GND, A, B

Application Examples:

• Modbus sensors such as weather stations on Arduino or ESP32
• Industrial sensors and controllers
• Galvanically isolated bus lines with interference or ground loops

Documentation:

• DFRobot Wiki DFR0845 with Arduino example
• Schematic (PDF)
• Datasheet (PDF)
• Dimension drawing (PDF)

Technical Data:

• Manufacturer: DFRobot
• Manufacturer SKU: DFR0845
• Supply voltage: 3.3 to 5 V
• Interfaces: UART (Gravity), RS485
• Baud rate: up to 1 Mbit/s
• Output power: 12 V, up to 2 W (about 160 mA)
• Isolation voltage: 3000 V DC
• Bus ESD protection: up to 15 kV
• Bus load: 1/8 unit load, up to 256 nodes
• Protection: bus fault, bus driver short circuit
• Operating temperature: -40 to 105 °C
• Dimensions: 45 × 36 × 18 mm
• Weight: 35 g

Scope of Delivery:

• 1× DFRobot RS485-to-UART Module with Active Isolation
• 1× Gravity UART cable 4-pin (PH2.0 to Dupont female)