RS232是一种传统的串行接口标准，它规定了数据终端设备（DTE）和数据通信设备（DCE）之间的信号连接、电气特性、接口机械特性和功能描述。USB是一种新型的通用串行总线，它由多家大厂商发起，可以使外设到计算机的连接更加高效、便利。

1、串口、COM口是指的物理接口形式(硬件)。而TTL、RS-232、RS-485是指的电平标准(电信号)。 2、接设备的时候，一般只接GND RX TX。不会接Vcc或者+3.3v的电源线，避免与目标设备上的供电冲突。 3、PL2303、CP2102芯片是 USB 转 TTL串口 的芯片，用USB来扩展串口(TTL电平)。

The Universal Serial Adapter is an open-source hardware project designed to bridge USB-C, RS232, and TTL communication. This fully assembled adapter is packed with features tailored for advanced ...

图1所示电路提供使用广泛的USB总线与RS-485或RS-232总 线之间的完全隔离连接。信号和电源隔离确保USB设备与 工业总线或调试 ...

A simple converter can be sourced online, but the only thing he could find locally that was even close was a USB to RS-232 converter. He used that component to craft his own USB to RS-485 bridge.

eSPI - Universal Serial Bus (USB) - Wi-Fi - WiMax - Insteon The details of each technology including specification, operation, security related matters, and many other topics are covered. The book ...

eSPI - Universal Serial Bus (USB) - Wi-Fi - WiMax - Insteon The details of each technology including specification, operation, security related matters, and many other topics are covered. The book ...

The supply of still-reliable RS232 mice must therefore be dwindling ... maybe you can make use of a USB to quadrature converter.