Serial Port Complete - Latest Microcontroller projects

Chapter 9

 Byte[] dataToSend = new Byte[5];

dataToSend[0] = (byte)'C';

dataToSend[1] = (byte)'M';

dataToSend[2] = (byte)'D';

dataToSend[3] = (byte)'1';

dataToSend[4] = 10;

myComPort.Write(dataToSend, 0, 5);

But the WriteLine method offers an easier way. The method converts each char-

acter in the String to a code and writes the codes, followed by a LF character, to

the port:

 dim dataToSend as String

dataToSend = "CMD1"

myComPort.WriteLine(dataToSend)

 String dataToSend;

dataToSend = "CMD1";

myComPort.WriteLine(dataToSend);

The SerialPort class provides methods for reading and writing individual Bytes

or Chars; arrays or portions of arrays of Bytes or Chars; Strings; Strings + New-

Line characters; formatted Strings; Boolean values, numeric types such as Deci-

mal, Int16, and others; and text representations of numeric values. When

reading data, most methods block (don’t return) until at least one byte or Char

is available or a timeout occurs. The ReadExisting method is an exception that

returns immediately whether data is available or not. The BytesToRead prop-

erty provides a way to find out if data is available before attempting a read oper-

ation. Methods that write data also block until the write buffer is empty.

Attempting to read or write to a port that isn’t open raises an InvalidOperation-

Exception. To prevent the exception, code can check to ensure the port is open

and open the port if needed before reading or writing to the port.