Hello, I'm new to arduino. I would like date and time stamp into the serial output.how can this be done without any extra hardware. if not possible, please do recommend me any rtc that i can use to do this.
I assume that the serial output is going to a PC of some sort and that the output will consist of ascii text.
The Arduino can measure elapsed time but without an RTC or a network interface it has no way of knowing what date/time it is starting from. You could use the serial link to send it the initial date/time, but you'd need to do that every time the Arduino was restarted and to me that does not seem feasible. It is far more sensible to prefix the output with a timestamp on the PC side. What operating system is the PC running, and what are you trying to do with the serial data once it reaches the PC?