how are you?
I'd like to ask you few questions about the C programming. I have a signal TTL pulse arrive on the PIN RxD of the serial port COM1 (DB9). Normally, the program will be in waiting mode (the TTL signal is 0), then, once the TTL raise to 1 (a pulse)(and go back to 0 just after-about 4ms) for the first time, the program start to count. After 20 times that the TTL signal raises, the program will send a message through the port COM1. I'm really newbie in C, so, if someone can explain me how to do that, that will be really great.
Thank you very much