PCF8574 IO Expansion Board

The PCF8574 I/O Expansion Board adds 8 bidirectional digital I/O pins to any microcontroller via just 2 I2C wires (SDA + SCL). Chain up to 8 modules on the same bus for up to 64 additional I/O pins. Onboard address selection jumpers (A0, A1, A2). Interrupt output pin for instant input change notification. Compatible with Arduino, ESP32, and Raspberry Pi.

Specifications:

• IC: PCF8574
• Interface: I2C (2-wire)
• I/O Pins: 8 (bidirectional)
• Supply Voltage: 2.5–6V
• Max Devices per Bus: 8 (64 total I/O)
• Address Selection: Jumpers A0, A1, A2
• Interrupt Output: Yes

Applications:

• Expanding digital I/O on Arduino, ESP32, Raspberry Pi
• Keypad and button matrix scanning
• Multi-relay and LED array control
• I2C-based GPIO expander in space-constrained designs