PCF8575 I2C IO Expander Module – 16 I/O Pins for Arduino

PCF8575 I2C to 16-Channel IO Expander Module for Arduino

Expand your microcontroller's GPIO capabilities in seconds with the PCF8575 IO Expander Module. Using just two I2C bus lines (SDA & SCL), this compact SMD module adds a full 16 bidirectional input/output channels to any Arduino, Raspberry Pi, or compatible development board — perfect for projects that demand more pins than your microcontroller natively provides.

Made in Mainland China.

Key Features

• 16 Bidirectional I/O Pins — Control up to 16 independent digital inputs or outputs via a single I2C interface
• Wide Supply Voltage — Operates reliably from 2.5 V to 5.5 V DC, compatible with both 3.3 V and 5 V systems
• I2C Interface — Only 2 wires needed (SDA + SCL), leaving the rest of your pins free
• Addressable — Hardware address pins allow multiple PCF8575 modules on the same I2C bus for even more I/O expansion
• SMD Package — Compact, low-profile design ideal for embedded and prototype builds
• Plug-and-Play — Compatible with Arduino IDE, ESP8266, ESP32, STM32, and more
• New Condition — Ships as brand-new, unused module

Specifications

• Chip: PCF8575
• Interface: I2C (2-wire)
• I/O Channels: 16 (bidirectional)
• Supply Voltage: 2.5 V – 5.5 V DC
• Package: SMD
• Quantity: 1 module per order
• Condition: New
• Origin: Mainland China

What's in the Box?

• 1 × PCF8575 IO Expander Module

Works Great With

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Frequently Asked Questions

Q: What microcontrollers is the PCF8575 IO Expander Module compatible with?

A: The PCF8575 IO Expander Module is compatible with any microcontroller that supports I2C communication, including Arduino (Uno, Mega, Nano), ESP8266, ESP32, STM32, and Raspberry Pi. As long as your board has SDA and SCL pins, you can integrate this module easily.

Q: How many PCF8575 modules can I connect to the same I2C bus?

A: You can connect up to 8 PCF8575 modules on a single I2C bus by using the onboard address pins (A0, A1, A2) to assign unique addresses. This gives you up to 128 additional bidirectional I/O channels on just two wires.

Q: Is the PCF8575 module compatible with both 3.3 V and 5 V systems?

A: Yes. The PCF8575 operates across a wide supply voltage range of 2.5 V to 5.5 V DC, making it fully compatible with both 3.3 V systems (like ESP32 and Raspberry Pi) and 5 V systems (like Arduino Uno).

Q: Do I need any special libraries to use this IO expander with Arduino?

A: Several open-source Arduino libraries support the PCF8575, such as the "PCF8575" library available in the Arduino Library Manager. Simply install the library, include it in your sketch, and you can read or write to all 16 I/O pins with just a few lines of code.