RS485 Shield for Arduino UNO

The RS485 Shield from DFRobot converts the serial interface of an Arduino UNO to RS485. This allows the Arduino to talk to industrial devices such as sensors, relay modules or meters, even over long cables up to about 1200 m. RS485 transmits differentially over two wires, several devices share the same bus. A switch disconnects the shield from the Arduino while a program is being uploaded. A second switch selects whether the shield switches between sending and receiving itself or whether the Arduino controls this via pin 2.

For noisy environments and long outdoor cables, DFRobot recommends an isolated interface, for example the DFRobot RS485-to-UART Module with Active Isolation.

Recommended Accessories:

• DFRduino UNO R3 Arduino Compatible Board
• USB to RS485 Converter Module

Features:

• Converts UART to RS485
• Standard RS485 connector, mini RS485 connector PH2.0 and RS485 pin header
• ON/OFF switch: OFF for uploading, ON for RS485
• AUTO/MANU switch: automatic or switching via pin 2 (HIGH send, LOW receive)
• LED for sending and receiving, reset button
• Soldering area for your own circuits
• PH2.0 connector for DFRobot RS485 sensors such as the URM04 ultrasonic sensor

Application Examples:

• Querying sensors and relay modules with Modbus RTU
• Networking Arduinos over long cables
• Reading meters and counters with RS485

Documentation:

• Wiki DFRobot DFR0259 with pinout
• Example automatic mode with Arduino (DFRobot)
• Schematic (image)

Technical Data:

• Manufacturer: DFRobot
• Manufacturer SKU: DFR0259
• Supply: 5 V from the Arduino
• Digital I/O pins: 16, including I2C
• Analog pins: 6, with supply
• RS485 connectors: standard, mini (PH2.0), pin header
• Pin for manual switching: D2
• Dimensions: 55 × 53 × 12 mm
• Weight: 27.8 g

Scope of Delivery:

• 1× RS485 Shield for Arduino