MareArts Computer Vision Study.: Serial Communication

Showing posts with label Serial Communication. Show all posts

7/19/2016

double memcpy to byte, example. useful in serial communication

When we program the serial communication,
You may want to send double number in bytes, rather than strings.

In other words,
when we have 123123123123.123123123123 double value.
it is better send value to byte of sizeof(double), rather than the 25byte string.

The following example further, an example that sends a double 3 dogs as a byte.
...

double x = 1234.4567+10;
  double y = 2345.6789+10;
  double z = 3456.7891+10;

  char sendingStr[sizeof(double) * 3];

  memcpy(sendingStr, &x, sizeof(double));
  memcpy(sendingStr + sizeof(double), &y, sizeof(double));
  memcpy(sendingStr + sizeof(double) * 2, &z, sizeof(double));

  m_Comm.WriteComm((BYTE*)sendingStr, sizeof(double) * 3);

...

In addition, if there is the data to be send prefix is as follows.
...

double x = 1234.4567+10;
  double y = 2345.6789+10;
  double z = 3456.7891+10;

  char sendingStr[sizeof(double) * 3 + 2];
  sendingStr[0] = '_';
  sendingStr[1] = 'E';

  memcpy(sendingStr + 2, &x, sizeof(double));
  memcpy(sendingStr + 2 + sizeof(double), &y, sizeof(double));
  memcpy(sendingStr + 2 + sizeof(double) * 2, &z, sizeof(double));

  m_Comm.WriteComm((BYTE*)sendingStr, sizeof(double) * 3 + 2);

...

And so if you want to change the byte sent back to double is when you do the following:
...

double Mx, My, Mz;
   memcpy(&Mx, MxyzStr, sizeof(double));
   memcpy(&My, MxyzStr+sizeof(double), sizeof(double));
   memcpy(&Mz, MxyzStr + sizeof(double)*2, sizeof(double));

...

5/16/2016

Serial communication(RS232C) source code (for wince and window)

The serial communication code is different for winCE and window.

In particular, Windows ce is attaching colon like 'com1:' an attempt to connect.

This attached code is very useful to start.

But comment is korean.

https://github.com/MareArts/ComThread

There are two folders. one is for wince, second is for window.

This source can be directly applied to the project.

Thank you.