This module is plug and play. It does not need driver. you can change RS232 levels to TTL level easily which makes software download and serial communication easy for STC series MCU.

4-pin interface were: +5 V to RT (without power stealing function, external 5V power supply is needed)

Module has two lights which are receive indicator and transmit indicator. They will flash when receiving or sending data.

Modules Test Methods :

1、Using serial extension cable to connect the computer and modules

2、Use wire to make send and receive pins shorted

3、Connect 5V power supply between VCC and GND

4、Open serial port debugging assistant on the computer and send data manually (not send files).