Common sense (very important):
TXD: Transmitter, generally expressed as its own transmitter, 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.
The TXD of itself is always connected to the RXD of the device during normal communication!
Self-receiving and self-transmitting: RXD is connected to the TXD of other devices during normal communication, so if you want to receive the data sent by yourself, as the name implies, that is, you receive the data sent by yourself, that is, your own TXD is directly connected to RXD to test its own transmission and reception Whether it is normal or not is the fastest and easiest test method. When a problem occurs, first do the test to determine whether the product is faulty. Also called loopback test.
TTL level: Usually data is expressed in binary, and it is stipulated that +5V is equivalent to logic “1”, and 0V is equivalent to logic “0”. It is called TTL signal system. It is a positive logic
RS232 level: from -12V to -3V, equivalent to logic “0”, logic level from +3V to +12V, equivalent to logic “1”, negative logic
1. The main chip is CP2102. After installing the driver, a virtual serial port is generated.
2. The USB power is taken. The output 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 always be on after the driver is installed correctly, the transceiver indicator will flash during communication, the higher the baud rate, the lower the brightness.
4. Supports waves from 300bps to 1Mbps Special rate
5. Communication format support: 1) 5, 6, 7, 8 data bits; 2) Support 1, 1.5, 2 stop bits; 3) odd, even, mark, space, none checksum
6. Support operating system ：Windows vista/xp/server 2003/200, Mac OS-X/OS-9, Linux
7, the USB head is a male head, which can be directly connected to the computer USB port
8, the SMT components are produced by SMT technology, the quality is stable
9, no The volume with USB head is: (mm) The