I haven't tested it yet, but it came properly packaged and with a paper datasheet (imagine that). I'm pleased with what I see.

I needed to quickly evaluate a CAT9555 I2C port expander at work. This module worked perfectly. Being able to set a unique address using dip switch was very helpful. The headers made it super easy to wire up.

Functional, but mislabeled.I was ready to return this board twice... wasted a bunch of time because of incorrect/misleading silkscreening/labeling. Fix the labeling and I'll give it 5 stars.Two issues, as follows:1) The address select switch, as shipped, has all DIPs OFF, which one might figure is the default I2C address of 0x20. This is NOT the case, as the shipped config is actually address 0x27 (address lines pulled high).2) The GPIO numbering on the silkscreen does not match the GPIO numbering of the actual chip. Specifically, Port 1 is numbered backwards (P1.0 is actually IO1.7 on the chip, and P1.7 is IO1.0 on the chip).

This is a decent quality board and works well.You do need to pay close attention to the address switch. As shipped the switches are all off, but look at the silk screen beside the switch. That indicates that when the switch is off that is a logic 1 on the corresponding address line. That makes sense since you pull the corresponding address line low when the switch is closed.I checked and the silk screen for the P1.0 - P1.7 appears to be correct for the board that I received.If you need an IO Expansion module for your projects this would be a good choice.For more details for this module go to:seengreat dot com /cat9555/ioexpansionmodule which should take you to the wiki page for the module, note that it may be a bit slow to load. That will give you much more detail about the board and how to use it than the single page spec sheet included with the board.

This board is great. The header pins come pre soldered and it is easy to work with