Product Description:

PCF8574 is an IO port expansion module that uses the I2C protocol. It has three address pins and can allocate up to 8 addresses simultaneously. The board includes 8-bit bidirectional IO ports (P0-P7), each of which can be separately assigned as an input or output without the need for data direction control signals. When powered on, all IO levels default to high level upply voltage: 3.3V/5V Communication interface: I2C interface, 8-bit parallel port Interface type: pin or socket Interrupt output: connected to MCU interrupt pin, low level is valid I2C Address Setting Instructions The default I2C address of the module is 0x20 The I2C address can be set to 8 different addresses through A0-A2, as shown in the figure All jumpers are set on the "-" side, meaning LOW is a low level The "+" side is HIGH, which is a high level The range of addresses from 0x20 to 0x27 is shown in the table below, which means that one development board can simultaneously connect 8 PCF8574 modules