Isolated RS485 RS232 HAT for Raspberry Pi

This RS485 RS232 HAT from Waveshare is an isolated RS485 and RS232 expansion board designed for the Raspberry Pi.

It adopts the SC16IS752, SP3485 and SP3232 schemes, includes built-in power isolation, ADI magnetic coupling isolation, TVS, resettable fuses and other protection circuits.

The board offers RS485 and RS232 Support – RS232: Full-Duplex Communication (SP3232 Transceiver), RS485: Semi/Full-Automatic Communication (SP3485 Transceiver).

SPI pins are broken out for connecting with other development boards such as an Arduino.

Features

• Standard Raspberry Pi 40-pin GPIO header
• Adopts the combination scheme of SC16IS752, SP3485 and SP3232, converts SPI to one RS485 and one RS232 (communication rate up to 921600bps)
• RS485 supports manual or automatic sending and receiving of data, which can be set by DIP switch
• Onboard resettable fuse and protection diodes, ensures the stable output of RS485 current and voltage, prevent over-current and over-voltage, improved shock resistance
• Onboard TVS (Transient Voltage Suppressor), can effectively suppress surge voltage and transient spike voltage in the circuit, lightning proof & anti-electrostatic
• Onboard power supply and serial port transceiver indicators, easy to check the module power supply and communication status
• Breakout SPI control pins, for connecting with Arduinos and other host control boards
• Online development resources and manual

What’s Onboard?

1) Raspberry Pi GPIO interface
 – For connecting to the Raspberry Pi Board
2) MCU control interface
 – For connecting to other host boards such as Arduino
3) RS485 interface
4) RS232 interface (DB9 male)
5) SC16IS752 UART chip
6) SP3485 RS485 Transceiver
7) SP3232 RS232 Transceiver
8) 142 Digital Isolator chip
9) PC817 Optocoupler Isolation
10) B0505LS Power Isolation Module
11) RT9193-33 power chip
12) TVS (Transient Voltage Suppressor)
13) Resettable Fuse
14) Status Indicator
 – PWR: Power indicator
 – RXD/TXD: UART transceiving indicator
15) RS485 120Ω terminal resistor on/off
16) Interrupt pin switching
 – Use D24 pin by default, can be changed to D16/D12/D25 pin by re-soldering the position of 0Ω resistor
17) RS485 operating mode selection
 – Semi-automatic: A=1, B=0
 – Full-automatic: A=0, B=1

Specifications

Package Contents

• 1x RS485 RS232 HAT
• 1x 2×20 pin header
• 1x Standoffs pack (2pcs)

Resources

• Product Wiki
• Schematic
• SP3485 Datasheet
• SC16IS752 Datasheet

Pinout