The USB Mini Module is a tiny PCB, the size of a standard 24 pin DIL chip. It’s a small development board that will simplify adding USB to your project.
If contains a FT8U245BM USB chip from FTDI. This chip is a complete USB interface, including the USB protocol stack.
It connects to your project through an 8-bit databus, a RD and WR line and 2 status pins. It doesn’t get simpler than this.
There’s no need to add a lot of code to handle the USB stack, all this is handles inside the FTDI chip. You just read from and write to the chip, by using the RD and WR lines, and monitoring the status flags that indicates if a character is ready, or the transmitter buffer is empty.
And there’s free OS drivers available for Windows, Linux and Macintosh computers.
These drivers work in two ways. One driver is a DLL that offers an API that you can interface to with your C or VB program. The other type adds a new comport to your PC. The speed on this new virtual comport is fixed and is the transfer rate on the USB link, typically up to 600-700 kByte/s.