C Program Using Getchar And Putchar
Try Serial.write('T') or Serial.print('T') (both equivalent if you're just passing a single character)When you say you want faster communication this is not the way to do it, the change in speed between Serial.print('hello') versus Serial.print('h'); Serial.print('e'); etc. Will be of the order of microseconds (if there even is much of a difference); whereas your baud rate of 9600 is equivalent to 960 characters a second, which is about 1 ms per character, so the function call will probably account for about a 1/1000th of the time. Try increasing your baud rate to 115200. The Serial.write does not block since version 1.0+ (unless you have filled the output buffer 64 chars so it has to wait for some room). It does the send via a 'background' interrupt handler.I have modified your program slightly. Adding a large delay in the loop shows 288 or 292 microseconds.
(the micros only measures in multiples of 4) Further adjusting the program to allow it run at full speed for 10 iterations shows that after a while the speed is 428-odd microseconds you see. The output buffer is full. 115200 baud (Serial uses around 10 bits to transmit 8 bits due to startbit, parity etc) is 11520 bytes a second. Which works out at 434 micros seconds for 5 bytes.
C Program Using Getchar And Putchar Video
Ah-ha, I think the number match.Lastly your printval routine does the same thing that Serial.print needs to do - convert the binary value (I think that is what you call raw int) to a number of ASCII characters which give you the humanreadable representation of the number. The very small difference between the two methods reflect the efficiency of the program.
The source is all available to you if you want to learn. However, I think in this case it would be more useful for you to understand how serial communications works and especially how to perform serial flow control and rate limiting.
The serial link will be much, much slower than the processors reading and writing over it, and execution time of the code doing the reading and writing is largely irrelevant. What is relevant is understanding how fast the serial link will go, and how to control your sender so that it sends data at that speed without overflow or underflow.