[Question note] [Serial port can only display cannot be entered]

Problem Description:

In the experiment, the serial port can not be input, but there is output display. After changing a serial cable, the signal can be displayed and received normally.

Problem Analysis:

The serial port has two signal lines, TX (transmit signal) and RX (Receive signal). The serial port has the output to indicate that the transmission signal is in normal operation, it is possible that the receiving signal cannot be entered. by short-connect TX and RX, the transmission signal is input directly to the receiving signal, if it is not working correctly, the receiving signal is broken.

Detailed steps:

1. Connect the serial line to the PC and open the serial terminal

2. Short-connect TX and RX signals

3. On the keyboard input, if there is a return on the screen instructions, TX and RX are working normally; otherwise, the serial port is bad.

[Question note] [Serial port can only display cannot be entered]