Hello just want to ask whether I can use file management in uVision3? Because I tried to use which is this " file *fp;" but i say file is an undefined identifier. What should I do to open a file to read and write can anyone tell me thanks!
The reason why I want to open a file to read and write is because I want to pass value from other program to this program. If anyone know the other method can teach me please thank alot!
The big attention people give to all of Tsuneo Chinzeis posts can probably be seen as an indication that the "full USB" route is way harder than using a serial-to-USB chip.
The lack of other people who off-load Tsuneo Chinzei helping people should probably also be seen as an indication.
There are of course quite a number of people who do manage to get their USB solutions to work without asking for help here, but the percentage of people getting stuck with their USB implementations seems to be way higher - I hardly see anyone getting stuck with a serial-to-USB solution.
So in the end, I think that for a high-volume product, it may be important to use a chip with built-in USB support since it may give a lower production price. But for a lot of people, the savings on the development time may fincance the extra hardware. Especially if it also gives a shorter time-to-market.
Since all USB I have done has been masters (not slaves) my reading of the SILabs USb section has not been exhaustive, just "reading out of interest". However I think that I have not seen any great difficulty in implementing what is discussed here (a replacement for RS-232) but the difficulties has been in areas like "higher speed" "large packet size" "multiple PIDs" etc.
Erik