Dual-channel RS485 Expansion Hat for Raspberry Pi 4B

RS485 is a widely used serial communication standard known for its robustness against noise, ability to transmit data over long distances, and support for multi-drop configurations. It employs a differential transmission method that effectively suppresses common-mode interference. To ensure smooth long-distance communication, RS485 requires a pair of twisted-pair cables and two terminal resistors to prevent signal reflection.

 

The Modbus protocol is an architecture based on a master/slave model that facilitates communication between devices using the RS485 standard. Each slave device is assigned a unique address, allowing the master device to send commands for execution. Modbus commands are equipped with a check code to ensure data integrity and enable operations such as modifying register values, controlling or reading I/O ports, and retrieving data from devices.

 

The Raspberry Pi RS485 HAT is a dual-channel expansion board designed specifically for the Raspberry Pi. It incorporates an isolated transceiver that provides isolation for RS485, enhancing the reliability and resistance to interference of data transmission on each channel. Additionally, the HAT includes embedded protection circuits such as a lightning and surge protector, a TVS diode, and power supply isolation to effectively safeguard the Raspberry Pi development board.

Furthermore, the order includes a screw accessory kit that enables users to securely attach this board to a Raspberry Pi controller.