How to find out time difference between 2 consecutive characters coming in

Question

Hi
Data is coming on serial port and m taking this data in a input stream.I need to know the time difdference between consecutive characters.Any ideas?

Answer 1

What do you mean? If you meassure the time between two characters, you want to calculate how accurate it is? First you would need to find out how accurate the System.currentTimeMillis is on the platform you run on. That may be easy
long start = System.currentTimeMillis();
long end;
while ((end = System.currentTimeMills()) == start);
long delta = end - start;But sometimes (on win98) it reports 50, other times 60. So its not quite accurate. But you could redo that test a couple of times and take the avg or the max.
Then if you get a time difference of 0ms between two characters, you know it will be somewhere 0 and 60ms. If you get 60ms between two characters, you know it will be somewhere between 0 and 120 ms. It's +/- delta seconds accurate.
Would this be a way to calculate the percentage accuracy: 100.0-100.0*delta/(time+delta)
Still better to meassure the time over more than just 2 characters unless it is a very slow stream.