Serial communication over RS232 and USB

Question

I plan to write serial driver to send data from target to host. The target is a renasas RX62N. And the host is windows 8.1. The target has RS232 port and the host has a USB port. I plan to use a converter cable with DB9(not sure) and USB connectors. 1) would like to know if I can send and receive from target and host? 2) would like to know if there is a way of getting around writing USB driver to send and receive from host is there software(Program) that could monitor usb port and send and receive dats over USB port? Ive seen software that let you send data and see the data receive by a port.

Answer 1

The USB<->RS-232 converter cable will appear to the PC host as a legacy serial port, support for the CDC/ACM USB profile that implements this port emulation is built into Windows, Linux and OSX. In windows however you will normally have to install "driver" which in most cases will simply be a INF file that maps the cable's USB vendor/product ID to the usbser.sys devive driver. Some USB/Serial devices may have custom drivers.

Common USB CDC/ACM devices from FTDI and Prolific will install drivers automatically via Windows Update (though historically Prolific drivers have been problematic - though recently they have improved).

At the target end, you communicate via the UART that is wired to the RS-232 line driver as you would normally.

For basic testing and keyboard/screen console access to your target, you van use any terminal emulator software such as TeraTerm, HyperTerminal, or Putty.

Answer 2

(1) RS-232 is bidirectional. You can send and receive at the same time. (2) You do not have to write a USB driver for the host. Windows has this built in. Use the standard Windows serial I/O calls. They work the same way for serial ports and for USB to serial converters.