> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt

# Dual-channel RS485 Expansion Hat for Raspberry Pi 4B

**Type:** Product page · **SKU:** DFR0824 · **Brand:** [DFRobot](https://core-electronics.com.au/brands/dfrobot-australia)
**Page:** https://core-electronics.com.au/dual-channel-rs485-expansion-hat-for-raspberry-pi-4b.html ([markdown](https://core-electronics.com.au/dual-channel-rs485-expansion-hat-for-raspberry-pi-4b.html.md))

Want to increase reliability and anti-interference for data transmission in your industrial applications? Try the RS485 Expansion HAT for Raspberry Pi....

## Pricing

- **Price:** $50.25 (inc GST) — $45.68 AUD, exc GST
- **Quantity discounts:** 6+ $43.40 (exc GST) · 12+ $41.57 (exc GST)

## Availability & dispatch

- Available with a lead time — expect dispatch between Aug 31 and Sep 02.

## How to buy

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- **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there.
- **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works)
- **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt
## Description

**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](https://www.dfrobot.com/category-269.html) designed for the [Raspberry Pi](https://core-electronics.com.au/raspberry-pi.html) 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](https://www.dfrobot.com/topic-272-184.html) 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](https://core-electronics.com.au/attachments/localcontent/Connection-Diagram_12723c0912d.png)**

**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
- 120O 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

- [Product wiki](https://wiki.dfrobot.com/SKU_DFR0824_RS485_Expansion_HAT_for_Raspberry_Pi)
- [Schematics](https://core-electronics.com.au/attachments/localcontent/18e31c27d0e3d47e5cbf3b717e3ad190_291194de5d7.PDF)
- [Design Document](https://core-electronics.com.au/attachments/localcontent/515a0209d86fcbf9afcc2a32d6abeaaf_24118523872.rar)
- [Model File](https://core-electronics.com.au/attachments/localcontent/206232d618afa04e69fac7418fc5abf8_88372b6b441.rar)
- [CAD File](https://core-electronics.com.au/attachments/localcontent/5b85f226b5b081ddff5c5d5abe6b33ed_12041e9da38.rar)
- [TP75176E Datasheet](https://core-electronics.com.au/attachments/localcontent/cf318d0de115098e8aa88f5806c6d6cd_15285955d0b.PDF)
 
### Parts List

- RS485 Expansion HAT for Raspberry Pi ×1
- Copper Column & Screw ×4

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/D/F/DFR0824-1.jpg)