RS422 / RS485 Shield for Arduino

Professional RS422/485 Interface Extension for Arduino Uno

The Arduino shield is a de-facto standard for extension boards not only for the Arduino but also for demoboards and SBC of different manufacturers. A good reason to create for the Arduino a RS422 / RS485 extension in the same style as our RS485 HAT for Raspberry Pi.

Some RS485 shields for the Arduino are already available on the market, but these extensions are not suitable for professional use, because they come without a galvanic isolation between the RS485 bus and the Arduino. Without such isolation a damaging of the Arduino or malfunction of the device is possible, because of the large distances of a RS485 bus. Furthermore a full-duplex mode (RS422) is also integrated.

Our shield comes with a lot of additional features:


  • RS485 mode (half duplex)
  • RS422 mode (full duplex)
  • galvanic isolation between Arduino and connected RS485 bus
  • free choice of TX-pin between pins 0-5 
  • free choice of RX-pin between pins 0-5
  • enhanced ESD protection
  • adjustable automatic transceiver switching for RS485 mode
  • adjustable control of transceiver/receiver via pin 6 or 7
  • adjustable Pull-Up, Pull-Down und terminating resistors
  • indicator LEDs for RX and TX 
  • removable block terminal for bus connection
  • many options adjustable via DIP switches
  • stackable headers
  • can be configured for 3.3V and 5V logic


The RS485 is in use in many applications like industrial and home automation (for example MODBUS), lighting control (DMX), video surveillance (for example Pelco D) ...

If you like to know more about RS485 visit this website:




You may also like: RS422/RS485 HAT for Raspberry Pi



This kit is also available at


Datasheet RS485 Shield Arduino
Datasheet, Jumper & DIP Switch Settings
Datasheet RS485 shield Rev C.pdf
Adobe Acrobat Document 452.0 KB

Application note MODBUS

How to create a Modbus slave and master with Arduino and RS485 Shield.

How to use MODBUS
Application Note RS485 Shield ModBus Rev
Adobe Acrobat Document 264.6 KB
Sample code Arduino UNO
Compressed Archive in ZIP Format 2.4 KB
Sample code Genuino 101
Compressed Archive in ZIP Format 6.9 KB
Sample code STM Nucleo
Compressed Archive in ZIP Format 6.9 KB
Sample code D1 R32 (ESP32)
Compressed Archive in ZIP Format 7.2 KB
Sample code D1 R2 (ESP8266)
Compressed Archive in ZIP Format 7.3 KB

How to Use NMEA-0183 with Arduino

How to connect GPS, SONAR, sensors, auto pilot units etc. in ships and boats via NMEA 0183 to Arduino.

Application Note NMEA-0183
Application Note NMEA Arduino Rev A.pdf
Adobe Acrobat Document 331.1 KB

Up to Three RS485 Busses on One Arduino

This project will show you how to connect up to three independent RS485 buses to only one Arduino.


Application Multiple RS485 Busses Rev A.
Adobe Acrobat Document 191.9 KB

How to read out an electricity meter via Arduino

Read out total power consumption and real power value of a Holley Tech DZ541 electricity meter via Arduino, RS485 and SML protocol


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How to Use Incremental Encoders

How to connect incremental encoders for industrial use with RS-422 interface to an Arduino UNO.


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Application note DIN rail mount with ArduiBox

Application RS485 DIN rail mount Rev A.p
Adobe Acrobat Document 3.3 MB


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