c# serial port packt code example
Example: c# serial port
//Serial Ports are used to communicate with other independant devices over
//a serial COM. More at https://en.wikipedia.org/wiki/COM_(hardware_interface) and https://en.wikipedia.org/wiki/Serial_communication
//For windows .NET Framework (This will not work in .net core or on linux)
//You will be using IO.Ports
using System.IO.Ports;
//Only one source can use a serial port at a time so encaposlation is important
class MySerialPortClass : IDisposable
{
//This is the class that will do most of the heavy lifting
public SerialPort SerialPort { get; private set; }
//diffenent devices use diffent baud rates or rates of electrical symbol
//change. This will cause diffent rates of communication, but both devices
//must agree on a rate to exchange at. The most common is 6800 bauds.
const int DefualtBaudRate = 6800;
//The above is also true of the amount of bits in a attomic ecnoding in a
//message.The most common is 8 bits for a byte. Honesly this one rarely changes.
const int DefaultSize = 8;
//The same is true of the party bit. The party bit is to detect error.
//Hardware is often good enough now that is is not used often, but it adds
//a bit to the start and sets it to make sure the number of set bits is odd
//or even. Or it can be used to just mark the start, but stop bits are
//enough usally to mark at the end.
const Parity DefaultParityBit = Parity.None;
//Stop bits or period is to mark the end of a message. Usally one bit is used.
const StopBits DefaultStopBits= StopBits.One;
//since only one source can access a com at a time you may want to expose
//if it is open. It will also be useful for resource freeing after.
public bool Open { get; private set; } = false;
//It will also be useful for resource freeing after.
private bool Disposed { get; private set; } = false;
//In Constructor we should set all the com vars. But the one we havent
//defined a default yet is the com port name. This will change depeneding
//on the plug used or if a virual (USB) on is used. Check your
//'Device Manager' for valid ports it could be.
MySerialPortClass(string ComPort, int BaudRateValue = DefualtBaudRate, Parity Par = DefaultParityBit, int DataSize = DefaultSize, StopBits Stop = DefaultStopBits)
{
SerialPort = new SerialPort(ComPort, BaudRateValue, Par, DataSize, Stop);
}
//after all the set up you must open the port. If the port is in use you
//will get an exception and you may need to rest it or your computer to
//get it open. Agan only one source can use a port at a time.
void OpenPort()
{
Open = true;
SerialPort.Open();
}
//reading and writeing is simple after set up and opening, but for each
//device messages will have to be formated differntly. Check with your
//devices manual or data sheets for more on formatting.
//can read a single byte at a time for decoding messages as they come in
byte Readbyte()
{
return (byte)SerialPort.ReadByte();//cast is because dispite it being a byte ms made it an int container
}
char ReadChar()
{
return (char)SerialPort.ReadByte();//cast is because dispite it being a byte ms made it an int container
}
//or you can read a string out if you know messages are on a line or
//would rather mass decode
//to read all in the buffer into a string
string ReadExisting()
{
return SerialPort.ReadExisting();
}
//if you know messages are a line like in a doc
string ReadExisting()
{
return SerialPort.ReadLine();
}
//Lastly you can decode as a buffer if you know message lengths
//Not it will fill in the buffer you provide and not size.
public int Read(byte[] buffer, int offset, int count);
{
return SerialPort.Read(buffer, offset, count);
}
//You can simply write a sting out
public void Write(string text)
{
return SerialPort.Write(text);
}
//Or you can write from a buffer like in a stream
public int Write(byte[] buffer, int offset, int count);
{
return SerialPort.Write(buffer, offset, count);
}
//Or you can write a line from a string
public void WriteLine(string text)
{
return SerialPort.WriteLine(text);
}
//Lastly it is recomended thay you dispose of your class and free system
//Resorces
//Close will free the port for use by a different source
void Close()
{
Open = false;
return SerialPort.Close();
}
//allows a using statement to dispose after use elegantly
public void Dispose()
{
Disposed = true;
SerialPort.Close();
SerialPort.Dispose();
}
//in the garbage collection ensure disposal so port will open back up after.
~MySerialPortClass()
{
if(!Disposed)
{
Dispose();
}
}
}