I2C Port Expander Board (Arduino code included!) from Celtic Engineering Solutions on Tindie
MCP23008 - i2c 8 input/output port expander : ID 593 : $1.95 : Adafruit Industries, Unique & fun DIY electronics and kits
PCF8575 I2C IO Extension Shield Module 16 I/O Port Expander For Arduino PI | eBay
MCP23017 - i2c 16 input / output port expander - Melopero Electronics
Port Expander Library
MAX7321 I2C Port Expander with 8 Open-Drain I/Os | Analog Devices
GMS 10 | Garmin
SF-3 Port Expander | Celtic Engineering Solutions
PCF8575 I2C IO Extension Shield Module 16 I/O Port Expander Arduino PI | eBay
Atlas Scientific 8:1 Serial Port Expander
Adafruit GPIO Expander Bonnet - 16 Additional I/O over I2C : ID 4132 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits
PCF8574 I2C to 8-bit digital port expander
Inline MCP23017 I2C 16-bit Port Expander Breakout Board — PMD Way
Raspberry Pi Port Expander HATs | The Pi Hut
I/O Expander - MCP23008 - COM-15099 - SparkFun Electronics
MCP23017 - i2c 16 input/output port expander
Daktronics Port Expander - Graphics Outfitters
10pcs Pcf8575 Module Expansion Io Port Expander Board Dc 2.5-5.5v I2c Communication Control 16 Io Ports For Arduino - Integrated Circuits - AliExpress
RPI SHD DOUBLER: Raspberry Pi Shield - GPIO port expander at reichelt elektronik
Daktronics Port Expander – Serial Tools
CTI 2571 505 SERIES PROGRAM PORT EXPANDER | eBay
New 16-bit GPIO Port Expander, Provides I2C interface and Level Shifting for any Peripherals
Pcf8575 Io Expander Module I2c To 16io Integrated Circuits For Arduino - Instrument Parts & Accessories - AliExpress
MikroElektronika - Port Expander Board - MCP23S17 Development Tool
CISCO UCSB-MLOM-PT-01 - Cisco UCS Port Expander Card (mezz) for VIC
AK-PCF8575 – I2C 16-bit IO Expander Breakout | Artekit Labs
MCP23017 I2C 16-bit Port Expander Breakout Board - Ten Pack — PMD Way
