SPECIFICATIONS

2-Channel Isolated RS485 Expansion HAT For Raspberry Pi, SC16IS752+SP3485 Solution, With Multi Onboard Protection Circuits

Overview

This is a 2-channel isolated RS485 expansion HAT designed for Raspberry Pi, adopts the SC16IS752+SP3485 solution, with embedded protection circuits such as power supply isolation, ADI magnetical isolation, and TVS diode, etc.

It is easy to control the 2-channel RS485 for auto transceiving via SPI interface. Due to its fast communication, stability, reliability, and safety, it is an ideal choice for fields like industrial automation.

Features

• Standard Raspberry Pi 40PIN GPIO extension header, supports Raspberry Pi series boards

• Adopts SC16IS752+SP3485 dual chip combination, converts SPI to RS485, data rate up to 921600bps

• Allows transceiving data manually or automatically, configured by DIP switch

• Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, lightning-proof & anti-electrostatic

• Onboard auto-recovery fuse and protection diodes, ensures the current/voltage stable outputs, provides over-current/over-voltage proof, improves shock resistance

• Onboard LEDs for indicating the power and transceiver status

• Breakout SPI control pins, for connecting with host control boards like Arduino

• Comes with development resources and manual (examples in C and Python)

Specifications

• UART expansion chip: SC16IS752

• RS485 transceiver: SP3485

• Communication interface: SPI

• Data rate: 300 ~ 921600 bps

• Operating voltage: 3.3V / 5V

• Dimensions: 65mm × 56.5mm

• Mounting hole size: 3.0mm

What's on Board

1. SC16IS752 UART expansion chip

2. ADUM1412 digital isolator

3. PC817 optocoupler

4. SP3485 RS485 transceiver

5. B0505LS power supply isolation module

6. RT9193-33 power chip

7. SMAJ12CA transient suppress diode array

8. Auto-recovery fuse

9. Status indicator
   PWR: power indicator
   RXD/TXD: UART transceiving indicator

10. Raspberry Pi GPIO connector: for connecting Raspberry Pi

11. RS485 terminal

12. MCU control header: for connecting host control boards like Arduino

13. 120Ω terminal resistor switch

14. Interrupt pin switch

15. Operating mode selection
    Half-auto: A=0, B=1
    Full-auto: A=1, B=0

Example

Pinouts

Dimension

Development Resources

Wiki : www.waveshare.com/wiki/2-CH_RS485_HAT

1. 2-CH RS485 HAT x1

2. 2x20PIN female pinheader x1

3. RPi screws pack (2pcs) x1