Dual-channel RS485 Expansion Hat for Raspberry Pi 4B
68 units will be available shortly.
What is RS485?
RS485 is a common serial communication standard with features such as good noise rejection, long transmission distance, and multi-drop capability. It transmits data using a differential transmission method, which allows it to suppress common-mode interference. RS485 requires a pair of twisted-pair cables and two terminal resistors to eliminate signal reflection during long-distance communication.
What is the Modbus Protocol?
Modbus is a master/slave architecture protocol used for communication between devices over RS-485. It uses unique addresses for each slave device to execute commands from a master device. Modbus commands include a check code to ensure data integrity, and can be used to change values in registers, control or read I/O ports, and retrieve data from devices.
Raspberry Pi RS485 HAT Introduction
This dual-channel RS485 expansion HAT designed for the Raspberry Pi adopts an isolated transceiver to achieve isolation for RS485, which increases the reliability and anti-interference of data transmission in each channel. And it features embedded protection circuits such as a lightning and surge protector, a TVS diode, and power supply isolation to protect the Raspberry Pi development board effectively.
Besides, the order includes a screw accessory kit that allows users to tightly fix this board onto a Raspberry Pi controller.
Wiring Diagram of RS485 Expansion HAT and Laser Ranging Sensor
Features
Dual Channel RS485
Electrical & signal isolation
Lightning & surge protection
Transient voltage suppressor
RX/TX data transmitting/receiving indicator
Applications
Agricultural Internet of Things
Warehouse Internet of Things
Indoor and Outdoor Environmental Monitoring
Lighting Control
Security Access Control System
Specification
Operating Voltage: 3.3V
RS485 Transceiver: TP75176E
Serial Chip: CH432T
RS485 Communication Interface ×2
Power Indicator: red
TX Communication Indicator: blue
RX Communication Indicator: green
120Ω Terminal Resistance: ×2
Wiring Method: 5.08-3P pluggable terminal block
Raspberry Pi 3B+/4B Supported
Mounting Hole Size: diameter 2.5mm
Dimension(Package Not Included): 56×65mm/2.20×2.56”
Documents
Shipping List
RS485 Expansion HAT for Raspberry Pi ×1
Copper Column & Screw ×4
The Dual-channel RS485 Expansion Hat for Raspberry Pi 4B appears in the following collections:
SKU DF-DFR0824
by Little Bird
