I have an application that requires handling bi-directional data on RS-232 and USB ports. Am already familiar with Stellaris parts but have not worked with USB interface.
I have an EKS-LM3S3748 Eval Kit and tried to run the "usb_dev_serial" demo to get familiar with the USB interface and library, but don't understand what the demo program is supposed to do.
I thought at first the program worked like an FTDI adapter cables, RS-232 on one end and USB on the other. The demo program is written to work with U0Tx/Rx. Looking at the eval board schematic the UART0 pins tie in to the FT2232 and CPLD, so there is no way to access these pins directly.
I changed the demo program to run with UART1 (added "#define REDIRECT_UART1" and modified vector table) and tried inputting TTL RS-232 to U1Rx, but so far that doesn't work. In the meantime I'm hoping someone can briefly explain how the demo program works and if there is a better way to exercise the USB interface. Thanks.