Fclose(obj) disconnects obj from the device, where obj is a serial port object or an array of serial port objects. Examples This example creates the serial port object s on a Windows ® platform, connects s to the device, writes and reads text data, and then disconnects s from the device using fclose. You can connect only one serial port object to a given device. Some properties are read-only while the serial port object is open (connected), and must be configured before using fopen. Examples include InputBufferSize and OutputBufferSize.
The Serial Port Session
This example describes the steps you use to perform any serial port task from beginning to end.
Create Serial Port Object. Establish a connection between MATLAB and the device using the serial port. Configure Serial Port Communication Settings. Set properties associated with the device baud rate and serial data format. Write and Read Serial Port Data. Write and read both text and binary data with a serial port device. Use Callbacks for.
The serial port session comprises all the steps you are likely to take when communicating with a device connected to a serial port. These steps are:
- Find your serial ports — Display a list of serial ports on your system using the
serialportlist
function. - Connect to a serial port device — Connect to a device for a specific serial port using the
serialport
creation function.Configure properties during object creation if necessary. In particular, you might want to configure properties associated with serial port communications such as the baud rate, the number of data bits, and so on. Alter the necessary device settings by configuring property values, read data, and write data. - Configure properties — To establish the desired serial port object behavior, assign values to properties using dot notation.In practice, you can configure many of the properties at any time including during, or just after, object creation. Conversely, depending on your device settings and the requirements of your serial port application, you might be able to accept the default property values and skip this step.
- Write and read data — Write data to the device using the
writeline
orwrite
function, and read data from the device using thereadline
orread
function.The serial port object behaves according to the previously configured or default property values. - Disconnect and clean up — When you no longer need the serial port object, remove it from the MATLAB® workspace using the
clear
command.
The serial port session is reinforced in many of the serial port documentation examples. To see a basic example that uses the steps shown above, see Query a Serial Port Device.
'port'
— Serial port name
character vector | string
Serial port name, specified as a character vector or string. The
seriallist
function provides a list of available serial ports. You must specify the port to create a serial port object.The port name depends on the platform that the serial port is on. This list is an example of serial constructors on different platforms:
Platform | Serial Port Constructor |
---|---|
Linux® 64 | s = serial('/dev/ttyS0') |
macOS 64 | s = serial('/dev/tty.KeySerial1') |
Windows® 64 | s = serial('COM1') |
Example:
s = serial('COM1')
Data Types:
char
| string
Name-Value Pair Arguments
Specify optional comma-separated pairs of
Example: Name,Value
arguments. Name
is the argument name and Value
is the corresponding value. Name
must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,..,NameN,ValueN
.s = serial('COM2','BaudRate',1200,'DataBits',7);
For a list of serial port object properties that you can use with
serial
, refer to Property Reference.It’s a struggle.It’s a process. But love is worth it.” NE-YO 2018.Follow NE-YO:Get GIFS from the video on GIPHY:Music video by Ne-Yo performing GOOD MAN. Ne yo mad download.
![Matlab serial port read Matlab serial port read](/uploads/1/3/4/1/134121149/896916447.jpg)
Note
Port must be the first argument used to create the serial object. You can then follow port with any number of supported name-value pairs.
'BaudRate'
— Rate at which bits are transmitted
9600 (default) | double
Rate at which bits are transmitted, specified as the comma-separated pair consisting of
'BaudRate'
and a double. You configure baud rate as bits per second. The transferred bits include the start bit, the data bits, the parity bit (if used), and the stop bits. However, only the data bits are stored.The baud rate is the rate at which information is transferred in a communication channel. In the serial port context, 9600 baud means that the serial port is capable of transferring a maximum of 9600 bits per second. If the information unit is one baud (one bit), the bit rate and the baud rate are identical. If one baud is given as 10 bits, (for example, eight data bits plus two framing bits), the bit rate is still 9600 but the baud rate is 9600/10, or 960. You always configure
BaudRate
as bits per second.Note
Both the computer and the peripheral device must be configured to the same baud rate before you can successfully read or write data.
Standard baud rates include 110, 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 38400, 57600, 115200, 128000, and 256000 bits per second.
You can also set the
BaudRate
property after creating the serial object using this syntax:Example:
s = serial('COM1','BaudRate',4800);
Data Types:
double
'ByteOrder'
— Byte order of the device
littleEndian (default) | bigEndian
Byte order of the device, specified as the comma-separated pair consisting of
'ByteOrder'
and littleEndian
or bigEndian
. If ByteOrder
is littleEndian
, the device stores the first byte in the first memory address. If ByteOrder
is bigEndian
, the device stores the last byte in the first memory address.For example, suppose the hexadecimal value 4F52 is to be stored in device memory. Because this value consists of two bytes, 4F and 52, two memory locations are used. Using big-endian format, 4F is stored first in the lower storage address. Using little-endian format, 52 is stored first in the lower storage address.
The byte order of
littleEndian
is the default and is used in read and write operations if you do not specify the property. You need to specify the property only to change the byte order to bigEndian
.You can also set the
ByteOrder
property after creating the serial object using this syntax:Note
Configure
ByteOrder
to the appropriate value for your device before performing a read or write operation. Refer to your device documentation for information about the order in which it stores bytes.Example:
s = serial('COM1','ByteOrder','bigEndian');
Data Types:
char
| string
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'DataBits'
— Number of data bits to transmit
8 (default) | 5 | 6 | 7
Number of data bits to transmit, specified as the comma-separated pair consisting of
'DataBits'
and 5
, 6
, 7
, or 8
, which is the default. Data is transmitted as a series of five, six, seven, or eight bits with the least significant bit sent first. At least seven data bits are required to transmit ASCII characters. Eight bits are required to transmit binary data. Five-bit and six-bit data formats are used for specialized communications equipment.Note
Both the computer and the peripheral device must be configured to transmit the same number of data bits.
In addition to the data bits, the serial data format consists of a start bit, one or two stop bits, and possibly a parity bit. You specify the number of stop bits with the
StopBits
property, and the type of parity checking with the Parity
property.You can also set the
DataBits
property after creating the serial object using this syntax:Example:
s = serial('COM1','DataBits',7);
Data Types:
double
'Parity'
— Type of parity checking
none (default) | odd | even | mark | space
Type of parity checking, specified as the comma-separated pair consisting of
'Parity'
and none
, odd
, even
, mark
, or space
.{none} | Default. No parity checking. Parity checking is not performed and the parity bit is not transmitted. |
odd | Odd parity checking. The number of mark bits (1s) in the data is counted, and the parity bit is asserted or unasserted to obtain an odd number of mark bits. |
even | Even parity checking. The number of mark bits in the data is counted, and the parity bit is asserted or unasserted to obtain an even number of mark bits. |
mark | Mark parity checking. The parity bit is asserted. |
space | Space parity checking. The parity bit is unasserted. |
Parity checking can detect errors of one bit only. An error in two bits might cause the data to have a seemingly valid parity, when in fact it is incorrect.
In addition to the parity bit, the serial data format consists of a start bit, between five and eight data bits, and one or two stop bits. You specify the number of data bits with the
DataBits
property, and the number of stop bits with the StopBits
property.You can also set the
Parity
property after creating the serial object using this syntax:Example:
s = serial('COM1','Parity','even');
Data Types:
char
| string
'StopBits'
— Number of bits used to indicate the end of a byte
1 (default) | 1.5 | 2
Number of bits used to indicate the end of a byte, specified as the comma-separated pair consisting of
'StopBits'
and 1
, 1.5
, or 2
. If StopBits
is 1
, one stop bit is used to indicate the end of data transmission. If StopBits
is 2
, two stop bits are used to indicate the end of data transmission. If StopBits
is 1.5
, the stop bit is transferred for 150% of the normal time used to transfer one bit.Note
Both the computer and the peripheral device must be configured to transmit the same number of stop bits.
Summary of the possible values:
{1} | Default. One stop bit is transmitted to indicate the end of a byte. Executable file location. |
1.5 | The stop bit is transferred for 150% of the normal time used to transfer one bit. |
2 | Two stop bits are transmitted to indicate the end of a byte. |
In addition to the stop bits, the serial data format consists of a start bit, between five and eight data bits, and possibly a parity bit. You specify the number of data bits with the
DataBits
property, and the type of parity checking with the Parity
property.You can also set the
StopBits
property after creating the serial object using this syntax:Example:
s = serial('COM1','StopBits',2);
Data Types:
double
Terminator character, specified as the comma-separated pair consisting of
'Terminator'
and a string. You can configure Terminator
to an integer value ranging from 0 to 127, which represents the ASCII code for the character, or you can configure Terminator
to the ASCII character. For example, to configure Terminator
to a carriage return, specify the value to be CR
or 13
. To configure Terminator
to a linefeed, specify the value to be LF
or 10
. You can also set Terminator
to CR/LF
or LF/CR
. If Terminator
is CR/LF
, the terminator is a carriage return followed by a line feed. If Terminator is LF/CR
, the terminator is a linefeed followed by a carriage return. Note that there are no integer equivalents for these two values.![Matlab close all serial ports Matlab close all serial ports](/uploads/1/3/4/1/134121149/266238540.png)
Additionally, you can set
Terminator
to a 1-by-2 cell array. The first element of the cell is the read terminator and the second element of the cell array is the write terminator.When performing a write operation using the
fprintf
function, all occurrences of n
are replaced with the Terminator
property value. Note that %sn
is the default format for fprintf
. A read operation with fgetl
, fgets
, or fscanf
completes when the Terminator
value is read. The terminator is ignored for binary operations.You can also use the terminator to generate a bytes-available event when the
BytesAvailableFcnMode
is set to terminator
.You can also set the
Terminator
property after creating the serial object, using this syntax:Example:
s = serial('COM1','Terminator','CR');
Matlab Serial Port Is Not Available
Data Types:
char
| string