USB to 232 circuit Q & A and comparison of common chips

USB to 232 circuit Q & A and comparison of common chips

Find a good article in a forum and share it. 1. Is this conversion circuit used in two directions? That is, the RS232 interface device can be plugged into the USB port of the PC computer, and the USB interface device can also be plugged into the RS232 port of the PC computer? 2. Do drivers need to be designed by themselves? Can it be downloaded from the Internet? A: strictly speaking, this type of chip should not be called a "USB to 232" chip, because its interface is not a RS-232 level (TTL or CMOS level ), but it is not like "USB to UART" because it has all the other signals defined in the RS-232 except rxd and txd. It should be called a USB protocol and a 232 protocol conversion chip. Since the RS-232 interface slowly fade out on the computer, and USB bus interface has become the mainstream computer configuration, but there are a lot of equipment using RS-232 interface and the corresponding software, and this type of conversion chip is a virtual RS-232 interface on the USB, coupled with the driver software, on the computer to see is the addition of a serial port, so that the original device software is still used. With this type of chip and a RS232 level conversion chip, you can connect to the original RS232 interface device through the USB port, there are many such products on the market. In addition to compatibility with old devices, most computers use this chip to communicate with single-chip microcomputer (or other IC) with uart interfaces through USB ports ), it has the advantages of low cost, power-off from USB, relatively simple programming (equivalent to serial programming without worrying about complicated USB protocols), etc, it is widely used in mobile phones, digital cameras, printers, and other products. USB to 232 chip, the original serial port of the old devices and software compatibility is not very good, some equipment software may not be available or sometimes poor communication. However, this problem does not exist for new devices that use such chips. Note that when the serial port is not closed on the PC, pulling out the connection sometimes crashes. The RS232 interface device can be connected to the USB port of the computer through the "USB to 232" converter (not a chip) without changing the software. However, the USB interface device cannot be plugged into the RS232 port of the PC. The drivers for "USB to 232" chips are provided by chip manufacturers and downloaded from the Internet. 3. the commonly used chip cp2101 is easy to use. It is troublesome to install the driver, and the peripheral components are less USB to 232 circuit. I prefer ch341! In addition, ch341 can be switched to other interfaces: ft232bm is easier to develop, but more peripheral devices than cp2101 have a big head. Now ft232rl is available, with a high degree of integration and a low price of pl2303, which is the lowest price. However, the peripheral circuit is complicated and fts01. however, it has the most powerful functions. cp2101 has the simplest peripheral circuit and moderate price. Pv8651 seems to be compatible with pl2303.