Two Serial Ports RS485 and RS232 Stackable HAT for Raspberry Pi (v2.0)

This stackable HAT is an add-on board for Raspberry Pi that provides two UART ports supporting both RS485 and RS232.

The latest versions of the Raspberry Pi have up to four UART ports on the GPIO connector, but you cannot use them without a physical layer transceiver. This HAT is the perfect solution for connecting your Raspberry Pi to serial devices like sensors and industrial equipment. It supports RS485 and RS422 communication protocols, making it versatile for a wide range of applications.

The HAT requires no additional software as the drivers are included in the Linux kernel.

Features

• RS485 transceiver connected to Raspberry Pi UART1 (GPIO pins 8, 10)
• RS232 transceiver connected to Raspberry Pi UART3 (GPIO pins 32, 33)
• Compatible with Raspberry Pi versions 3, 4, and 5
• Stackable with any other HAT (only one card per Raspberry Pi)
• Compact size (93mm x 13mm)
• Pluggable Connectors 26-16 AWG wires
• Status LEDs on both serial ports
• No additional software required (drivers included in the Linux kernel)
• All mounting hardware included: stand-offs, screws and nuts
• ECCN Code EAR99

Compatibility

The card is compatible with Raspberry Pi versions from 2 to 5.

UART1 (pins 8, 10) is available on all Raspberry Pi cards, so the RS485 port will always work.

UART1 might not be available on older versions, or on other cards which emulate the Raspberry Pi GPIO connector.

Power requirements

The card takes 5V and less than 40mA of power from the Raspberry Pi GPIO connector.

Stacking multiple cards

Since the Two Serial Ports  Card uses the Raspberry Pi UART ports, only one card can be installed on each Raspberry Pi. However, the card is equipped with an extra tall 2x20 male-female connector and can be installed on top of any stackable HAT. Also, any Raspberry Pi HAT can be installed on top of the 2-Serial Ports Card

Mechanical Specifications

The Two Serial Ports Card is probably the smallest HAT in the world, measuring only 93mm x 14.2mm.

Specifications

• Data rates
  • RS485 Port: Max 921,600 bps
  • RS232 Port: Max 230,400 bps
• Port allocation
  • RS485  -> /dev.ttyAMA0
  • RS232 -> /dev/ttyAMA4

Resources

• Product downloads

Pinout

Package Contents

• 1x Two Serial Ports add-on HAT for Raspberry Pi
• 1x Mounting hardware pack
  • 2x M2.5 x 18mm male-female brass standoffs
  • 2x M2.5 x 5mm brass screws
  • 2x M2.5 brass nuts
• 2x Connector plugs