RS232-TTL Converter

From the shop's description

This module is plug and play. It does not need driver. you can change RS232 levels to TTL level easily. Module has two lights which are receive indicator and transmit indicator. They will flash when receiving or sending data. How to test RS232 module Connect the module to computer serial port Use wire to make send and receive pins shorted Connect 3.3V or 5V power supply between VCC and GND Open serial port debugging assistant on the computer and send data manually (not send files). If the data can be received correctly, it's all right. And the two led lights will flash at the same time. ​ SP3222E Datasheet