Eight Serial Ports 2-Layer Stackable HAT for Raspberry Pi

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.

The Eight Serial Ports HAT uses all four ports of the Raspberry Pi, plus eight additional ports from two 32-bit ARM Cortex processors, to implement all the common serial ports in use today.

The processors talk to the Raspberry Pi using only the I2C port, with the hardware address selectable from a DIP switch. One LED for each port shows when the port is active.

Compatibility

The card is compatible with Raspberry Pi versions from Raspberry Pi 3 to Raspberry Pi 5. Older versions of the Raspberry Pi might not have all four serial ports available on the GPIO connector.

Power Requirements

The card takes 5V and less than 100mA of power from an external 5V power supply. It also provides up to 3.5A of power through the hardware watchdog to the Raspberry Pi

Stacking Multiple Cards

Two 8-Serial Ports Cards can be stacked on top of one Raspberry Pi, implementing a total of 16 serial ports.

Features

• Three RS232 ports
• One RS485 port with a selectable terminator
• One RS422 port with a selectable terminator
• One CAN port
• One 1-Wire port
• One M-BUS port
• Compatible with all Raspberry Pi versions from 3 to 5
• Two Layer Stackable
• Onboard hardware watchdog
• Reset pushbutton
• Status LED indicators on each serial port and power
• No additional software required (drivers included in the Linux kernel)
• ECCN Code EAR99

Specifications

• RS485 Ports: Max 921,600 bps
• RS232 Ports: Max 230,400 bps
• RS422 Ports: TBD
• 1-Wire: TBD
• CAN: TBD
• M-BUS: TBD

Resources

The 8-Serial Ports Card does not require software. All the software drivers are part of the Linux kernel. Setup instructions can be found here.

• Downloads
• Schematic V1
• 3D Step Mode
• Setup and command line interface

Package Contents

• 1x Eight Serial Ports 2-Layer Stackable HAT for Raspberry Pi
• 4x M2.5x18mm male-female brass standoffs
• 4x M2.5x5mm brass screws
• 4x M2.5 brass nuts
• 10x Connector plugs