Use of do ... while

Rsadeika

The result that I am trying to get is, when I press the 'q' key, the program breaks out of the loop. Right now, it runs through once and then it does not do anything except respond to the 'q' press. I expect the program to keep posting a distance value while the 'q' has not been pressed. Anybody care to set me straight?

Thanks

Ray

void testping(void)
{
  int distance;
  print("Press 'q' to quit\n");  
//  while(getChar() != 'q')
//  while(1)
  do
  {
    distance = ping_cm(8);
    print("%c%d distance = %d%c cm",
      CRSRY,1, distance, CLREOL);
    pause(200);
  } while(getChar() != 'q');
}

David Betz

I think your problem is that getChar() will block until the user presses a key. You need something like peekChar() that will return a character if it is available and -1 if no key has been pressed. In other words, it won't block waiting for a key to be pressed. I'm not sure if such a function exists in the simple library but my guess is it would be "simple" to add. :-)

kuroneko

This may help http://forums.parallax.com/showthread.php/150019-program-stop-at-getChar()-and-readChar().