You are in a situation where you have a 5V device (like an Arduino) and you want to connect to a 3.3V sensor. The sensor is not 5V tolerant and direct connection to a 5V system will fry it instantly. This is where a logic level converter comes into the picture. It does level shifting, in this case from 5V to 3.3V and vice-versa. With this converter, both systems may talk to each other safely.
This board can do level shifting from anything to anything between 1.8V to 6V. It has 8 channels meaning you can connect up to 8 pins on each side. It is also bidirectional. The board will auto-detect the direction (input/output) and perform level shifting accordingly.
It is easy to use. The converter needs to be powered from two different voltage sources that your system is using. For example, connect a 5V to VCCA and 3.3V to VCCB and ground to GND pin.
Example:
Bidirectional conversion between 5V and 3.3V system.
Connect VCCA to 5V and VCCB to 3.3V
Connect GND to the respective system's ground
When there is a 5V TTL input on pin Ax, the converter will output 3.3V on pin Bx
When there is a 3.3V TTL input on pin Bx, the converter will output 5V on pin Ax
