hi

im new to this

trying to fiddle around with COM etc... so I can send signals using CreateFile() and WriteFile().

Almost there!

I am deving in C# but using low level calls from dllimport.

Current problem I have is that if I CreateFile() - I get a handler - cool
If I WriteFile() I get error 1359 which is ERROR_INTERNAL_ERROR - no idea what this is or how to resolve it

after reading more and more, came to the conclusion that you need to Set the comm state (parity settings, baud rate and so on) so I did this using SetCommState()

Now, when I set the DCB and give it to SetCommState with the CreateFile() handler (to COM3) I get error 6 which is invalid handler

?!?!!?!?

whats happening?