USB to TTL serial UART

TXD: Sending end, generally expressed as its own sending end, normal communication must be connected to the RXD of another device.

RXD: Receiver, generally expressed as its own receiver, normal communication must be connected to the TXD of another device. During normal communication, its own TXD is always connected to the device's RXD!

Self-receiving and self-transmitting: During normal communication, the RXD is connected to the TXD of other devices, so if you want to receive the data sent by yourself, as the name suggests, that is, you will receive the data sent by yourself, that is, your own TXD is directly connected to the RXD to test its own transmission and reception. Whether it is normal or not is a quick and simple test method. When there is a problem, first do the test to determine whether the product is faulty. Also called loopback test.

Level logic:

TTL level: Usually the data is expressed in binary, it is stipulated that +5V is equivalent to logic "1", 0V is equivalent to logic "0", called TTL signal system, it is positive logic

RS232 level: use -12V to -3V, equivalent to logic "0", +3V to +12V logic level, equivalent to logic "1", is negative logic

Product Description:

1. The main chip is CP2102. After installing the driver, a virtual serial port is generated.

2. USB power supply, the lead-out interface includes 3.3V (<40mA), 5V, GND, TX, RX, the signal pin level is 3.3V, positive logic

3. On-board status indicator, transceiver indicator, the status indicator will be always on after the driver is installed correctly, the transceiver indicator will flash when communicating, the higher the baud rate, the lower the brightness