writeline

Write line of ASCII data to serial port

Syntax

writeline(device,data)

Description

writeline(device,data) writes the ASCII text data followed by the terminator to the specified serial port. The function suspends MATLAB^® execution until the data and terminator are written.

Examples

Write and Read Line of ASCII Data from Serial Port Device

Create a connection to a serial port device. In this example, the serial port at COM3 is connected to a loopback device.

device = serialport("COM3",9600)

device = 

  Serialport with properties:

                 Port: "COM3"
             BaudRate: 9600
    NumBytesAvailable: 0

  Show all properties, functions

Check the default ASCII terminator.

device.Terminator

ans = 

    "LF"

Set the terminator to "CR" and write a string of ASCII data. The writeline function automatically appends the terminator to the data.

configureTerminator(device,"CR")
writeline(device,"hello")

Write another string of ASCII data with the terminator automatically appended.

writeline(device,"world")

Since the port is connected to a loopback device, the data you write to the device is returned to MATLAB. Read a string of ASCII data. The readline function returns data until it reaches a terminator.

readline(device)

ans = 

    "hello"

Read a string of ASCII data again to return the second string that you wrote.

readline(device)

ans = 

    "world"

Clear the serial port connection.

clear device

Input Arguments

device — Serial port connection

serialport object

Serial port connection, specified as a serialport object.

Example: writeline(device,1:5) writes to the serial port connection device.

data — ASCII data

character vector | string scalar

ASCII data to write, specified as a character vector or string scalar of text.

Example: writeline(device,"*IDN?") writes the ASCII string "*IDN?"

Data Types: char | string

Version History

Introduced in R2019b