If you've ever tried to connect a 3.3V device to a 5V system, you know what a challenge it can be. The CJMCU bi-directional logic level converter is a small device that safely steps down 5V signals to 3.3V AND steps up 3.3V to 5V at the same time. This level converter also works with 2.8V and 1.8V devices. What really separates this Logic level converter from our previous versions is that you can successfully set your high and low voltages and step up and down between them safely on the same channel. Each level converter has the capability of converting 4 pins on the high side to 4 pins on the low side with two inputs and two outputs provided for each side. The level converter is very easy to use. The board needs to be powered from the two voltages sources (high voltage and low voltage) that your system is using. High voltage (5V for example) to the "HV" pin, low voltage (3.3V for example) to "LV", and ground from the system to the "GND" pin.