You create a serial port object with the
serialport requires the name of the serial port connected to your
device and the baud rate as input arguments. You can also configure property values
during object creation using name-value pair arguments.
Each serial port object is associated with one serial port. For example, connect to a device that is on serial port COM1 and configured for a baud rate of 4800.
s = serialport("COM1",4800);
If the specified port does not exist, or if it is in use, you cannot connect the serial port object to the device. The port name depends on the platform that the serial port is on.
You can also use the
serialportlist function to return a list of
all serial ports on a system, including virtual serial ports provided by USB-to-serial
devices and Bluetooth® Serial Port Profile devices. The list shows all serial ports that you have
access to on your computer and can use for serial port communication.
ans = 1×3 string array "COM1" "COM3" "COM4"
This table shows an example of serial constructors on different platforms.
s = serialport("/dev/ttyS0",9600);
s = serialport("/dev/tty.KeySerial1",9600);
Microsoft® Windows® 64-bit
s = serialport("COM1",9600);
The first time you try to access a serial port in MATLAB® using the
s = serialport("COM1",9600) call, make
sure that the port is free and is not already open in any other application. If the
port is open in another application, MATLAB cannot access it. After you access the serial port in MATLAB, you can open the same port in other applications, and MATLAB continues to use it along with any other application that has it open
The serial port object provides a convenient display that summarizes important configuration and state information. You can invoke the display summary in three ways:
Type the serial port object variable name at the command line.
Exclude the semicolon when creating a serial port object.
Exclude the semicolon when configuring properties using dot notation.
You can also display summary information using the workspace browser by right-clicking an instrument object and selecting Display Summary from the context menu.
The display summary for the serial port object
s on a Windows machine is given here.
s = serialport("COM4",9600)
s = Serialport with properties: Port: "COM4" BaudRate: 9600 NumBytesAvailable: 0 Show all properties, all methods Port: "COM4" BaudRate: 9600 NumBytesAvailable: 0 ByteOrder: "little-endian" DataBits: 8 StopBits: 1 Parity: "none" FlowControl: "none" Timeout: 10 Terminator: "LF" BytesAvailableFcnMode: "off" BytesAvailableFcnCount: 64 BytesAvailableFcn:  NumBytesWritten: 0 ErrorOccurredFcn:  UserData: 
Use dot notation to configure and display property values.
s.BaudRate = 4800; s.BaudRate
ans = 4800