2-Channel Isolated RS485 Expansion HAT for Raspberry Pi

This is a Raspberry Pi Hat for converting the SPI interface into the RS485 interface. The Hat can control 2 RS485 interfaces working at the same time.

Out of stock
  • 10+: $16.00



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 the SPI interface. Due to its fast communication, stability, reliability, and safety, it is an ideal choice for fields like industrial automation.


  • 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)


  • 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



VCC 5V 3.3V/5V power supply
GND GND Ground
SCK P21 (SPI1 SCLK) SPI clock input
MOSI P20 (SPI1 MOSI) SPI data input
MISO P19 (SPI1 MISO) SPI data output
CS P18 (SPI1 CS) SPI chip select
IRQ P24 Interrupt output
EN1 P27 Channel 1 TX/RX enable: high for TX, low for RX
EN2 P22 Channel 2 TX/RX enable: high for TX, low for RX


Part List

  1. 2-CH RS485 HAT x1
  2. 2x20PIN female pinheader x1
  3. RPi screws pack (2pcs) x1


HSCODE 8543909000
USHSCODE 8471490000



This blog will show you three ways to configure WiFi on your Raspberry Pi with both Raspberry Pi OS desktop and server, and it will also cover how to do it on a headless Raspberry Pi!



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