Review on HiLetgo PCF8574 PCF8574T IO Expansion Board I/O Expander I2C Evaluation Development Module (2pcs) by John Kahsar

Update: The seller got in touch to fix the issue and are very apologetic about the initial issue so I'm downgrading my rating to 2 due to the good quality Raised customer service to 4 stars. I ordered this two pack but one of them came without a square connector on the board. It's not damaged or broken, it doesn't exist at all! They just didn't solder the connector at the time of manufacture and put it in a pocket with no connector installed. The chips on the board were Philips A series (base address 0x38). Note that you need a pull-up resistor to drive anything with this chip (even to drive a relay via opto I had to use an external pull-up resistor. I have a 3.3kΩ pull -up resistor used when I used 3.3 I /OB it seemed to work fine)