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release

Release the GPS object

Since R2020b

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Syntax

release(gps)

Description

release(gps) release the system objects, allows configuration of non tunable properties, clear the buffers, and resets the values of SamplesRead and SamplesAvailable properties.

example

Examples

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Open Live Script

Read data from the GPS receiver connected to the host computer on a specific serial port.

Required Hardware

To run this example, you need:

  • UBlox Neo-6M GPS module

  • GPS antenna

  • USB to UART module

  • USB cable

  • Connecting wires

Hardware Connection

GPS_UART_USB_PC.png

Connect the pins on the UBlox Neo-6M GPS module to the pins on your USB to UART module. The connections are:

  • VCC - +5V

  • RX - TXO

  • TX - RXI

  • GND - GND

Connect the GPS antenna to the GPS module. Connect the USB to UART module to the host computer with a USB cable. GPS Fix can be easily acquired in locations that have a clear view of the sky. Wait for the GPS module to acquire satelite signals (Fix).This can be verified by checking the Fix LED (D1) of your GPS module.

Create GPS Object

Create a gpsdev object for the GPS receiver connected to a specific port. Specify the output format of the data as a timetable.

gps = gpsdev('COM4','OutputFormat',"timetable")
gps = 
  gpsdev with properties:

                         SerialPort: COM4	
                           BaudRate: 9600 (bits/s)

                     SamplesPerRead: 1	 
                           ReadMode: "latest"	 
                        SamplesRead: 0	 
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Read the GPS data

Read the GPS data and return them as a timetable.

[tt,overruns] = read(gps)
tt=1×5 timetable
              Time                         LLA               GroundSpeed    Course            DOPs                GPSReceiverTime     
    ________________________    _________________________    ___________    ______    ____________________    ________________________

    22-Mar-2021 15:31:15.190    17.47    78.343     449.6      0.25619       NaN      9.31    1.48    9.19    22-Mar-2021 10:01:14.000


overruns = 0

Display number of samples read and the samples available in the host buffer.

gps.SamplesRead
ans = 1

gps.SamplesAvailable
ans = 0

Release the GPS object to configure the non tunable properties. The release function also clears the buffer and resets the SamplesRead and SamplesAvailable properties.

release(gps)

Specify the number of samples per read to 2. Read the GPS data.

gps.SamplesPerRead = 2;
read(gps)
ans=2×5 timetable
              Time                         LLA               GroundSpeed    Course            DOPs                GPSReceiverTime     
    ________________________    _________________________    ___________    ______    ____________________    ________________________

    22-Mar-2021 15:31:17.178    17.47    78.343       450     0.063791       NaN      9.32    1.48     9.2    22-Mar-2021 10:01:16.000
    22-Mar-2021 15:31:17.178    17.47    78.343       450     0.063791       NaN      9.32    1.48     9.2    22-Mar-2021 10:01:16.000

Display number of samples read and the samples available in the host buffer.

gps.SamplesRead
ans = 1

gps.SamplesAvailable
ans = 0

Clean Up

When the connection is no longer needed, clear the associated object.

delete(gps);
clear gps;

Input Arguments

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The GPS sensor, specified as a gpsdev object.

Version History

Introduced in R2020b

See Also

Objects

Functions