I2C-UART Bi-Directional Logic Level Converter 5V-3.3V 2-Channel (ot8520)

Some modules work with 3.3V I2C or UART, then this module can convert the voltage if your system works with 5V. (e.g. your 5V Arduino) There is also a built-in voltage regulator that converts 5V to 3.3V up to 100mA, also useful if you need to power a module with 3.3V that does not have a built-in voltage regulator. The pins are listed at the bottom: Connect AVCC to 5V Connect ASCL to SCL/TX pin of 5V system Connect ASDA to SDA/RX pin of 5V system Connect AGND to GND of 5V system Connect BVCC to 3.3V of system Connect BSCL to SCL/RX pin of 3.3V system Connect BSDA to SDA/TX pin of 3.3V system Connect BGND to GND of 3.3V system This module is in principle only suitable for going from 5V to 3.3V. The voltage regulator can only convert 5V to 3.3V. If your system is 3.3V and you want to connect a 5V module, you must connect it as follows: Connect AVCC to 5V (5V power line) Connect ASCL to SCL/TX pin of 5V system Connect ASDA to SDA/RX pin of 5V system Connect AGND to GND of 5V system Do not connect BVCC Connect BSCL to SCL/RX pin of 3.3V system Connect BSDA to SDA/TX pin of 3.3V system Connect BGND to GND of 3.3V system Note: The pin headers for this module are not yet soldered. If you want to use the headers, you must solder them yourself.