ITEM NAME:1PCS PCF8574T I/O I2C Port Interface Support Cascading Extended Module D5G1 1PCS PCF8574T I/O I2C Port Interface Support Cascading Extended Module D5G1 The CJMCU-8574 is a CMOS circuit module that enables remote I / O expansion for most MCUs via two bi-directional buses. The device contains an 8-bit quasi-