Review on 🐻 4 Pack Serial Wombat 4B - I2C Smart I/O Expander with A/D Converter: Drive Servos, Switches, Quadrature Encoders, and UART/I2C Bridge - I2C Compatible with Arduino by Stephen Schmidt

These ICs are everything they advertise. I am planning to use 4 of these for an IoT application where my ESP32 Nodemcu board needs to communicate with 4 RFID modules. Since ESP doesn't have 4 serial ports and RFID modules don't support addresses, these serial wombats were the perfect solution. If you are familiar with i2c and uart in Arduino you can get them up and running in less than 30 minutes. It is clear that the manufacturer is enthusiastic about its project and has responded to support emails.