Java - GPS Bricklet 2.0

This is the description of the Java API bindings for the GPS Bricklet 2.0. General information and technical specifications for the GPS Bricklet 2.0 are summarized in its hardware description.

An installation guide for the Java API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (ExampleSimple.java)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletGPSV2;
import com.tinkerforge.BrickletGPSV2.Coordinates;

public class ExampleSimple {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;

    // Change XYZ to the UID of your GPS Bricklet 2.0
    private static final String UID = "XYZ";

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions
    //       you might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletGPSV2 gps = new BrickletGPSV2(UID, ipcon); // Create device object

        ipcon.connect(HOST, PORT); // Connect to brickd
        // Don't use device before ipcon is connected

        // Get current coordinates
        Coordinates coordinates = gps.getCoordinates(); // Can throw com.tinkerforge.TimeoutException

        System.out.println("Latitude: " + coordinates.latitude/1000000.0 + " °");
        System.out.println("N/S: " + coordinates.ns);
        System.out.println("Longitude: " + coordinates.longitude/1000000.0 + " °");
        System.out.println("E/W: " + coordinates.ew);

        System.out.println("Press key to exit"); System.in.read();
        ipcon.disconnect();
    }
}

Callback

Download (ExampleCallback.java)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletGPSV2;

public class ExampleCallback {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;

    // Change XYZ to the UID of your GPS Bricklet 2.0
    private static final String UID = "XYZ";

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions
    //       you might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletGPSV2 gps = new BrickletGPSV2(UID, ipcon); // Create device object

        ipcon.connect(HOST, PORT); // Connect to brickd
        // Don't use device before ipcon is connected

        // Add coordinates listener
        gps.addCoordinatesListener(new BrickletGPSV2.CoordinatesListener() {
            public void coordinates(long latitude, char ns, long longitude, char ew) {
                System.out.println("Latitude: " + latitude/1000000.0 + " °");
                System.out.println("N/S: " + ns);
                System.out.println("Longitude: " + longitude/1000000.0 + " °");
                System.out.println("E/W: " + ew);
                System.out.println("");
            }
        });

        // Set period for coordinates callback to 1s (1000ms)
        // Note: The coordinates callback is only called every second
        //       if the coordinates has changed since the last call!
        gps.setCoordinatesCallbackPeriod(1000);

        System.out.println("Press key to exit"); System.in.read();
        ipcon.disconnect();
    }
}

API

Generally, every method of the Java bindings that returns a value can throw a TimeoutException. This exception gets thrown if the device did not respond. If a cable based connection is used, it is unlikely that this exception gets thrown (assuming nobody unplugs the device). However, if a wireless connection is used, timeouts will occur if the distance to the device gets too big.

Beside the TimeoutException there is also a NotConnectedException that is thrown if a method needs to communicate with the device while the IP Connection is not connected.

Since Java does not support multiple return values and return by reference is not possible for primitive types, we use small classes that only consist of member variables. The member variables of the returned objects are described in the corresponding method descriptions.

The package for all Brick/Bricklet bindings and the IP Connection is com.tinkerforge.*

All methods listed below are thread-safe.

Basic Functions

public class BrickletGPSV2(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid:

BrickletGPSV2 gpsV2 = new BrickletGPSV2("YOUR_DEVICE_UID", ipcon);

This object can then be used after the IP Connection is connected (see examples above).

public BrickletGPSV2.Coordinates getCoordinates()

Returns the GPS coordinates. Latitude and longitude are given in the DD.dddddd° format, the value 57123468 means 57.123468°. The parameter ns and ew are the cardinal directions for latitude and longitude. Possible values for ns and ew are 'N', 'S', 'E' and 'W' (north, south, east and west).

This data is only valid if there is currently a fix as indicated by getStatus().

The returned object has the public member variables long latitude, char ns, long longitude and char ew.

public BrickletGPSV2.Status getStatus()

Returns if a fix is currently available as well as the, the number of satellites that are in view.

There is also a green LED on the Bricklet that indicates the fix status.

The returned object has the public member variables boolean hasFix and int satellitesView.

public BrickletGPSV2.Altitude getAltitude()

Returns the current altitude and corresponding geoidal separation.

Both values are given in cm.

This data is only valid if there is currently a fix as indicated by getStatus().

The returned object has the public member variables int altitude and int geoidalSeparation.

public BrickletGPSV2.Motion getMotion()

Returns the current course and speed. Course is given in hundredths degree and speed is given in hundredths km/h. A course of 0° means the Bricklet is traveling north bound and 90° means it is traveling east bound.

Please note that this only returns useful values if an actual movement is present.

This data is only valid if there is currently a fix as indicated by getStatus().

The returned object has the public member variables long course and long speed.

public BrickletGPSV2.DateTime getDateTime()

Returns the current date and time. The date is given in the format ddmmyy and the time is given in the format hhmmss.sss. For example, 140713 means 14.05.13 as date and 195923568 means 19:59:23.568 as time.

The returned object has the public member variables long date and long time.

public BrickletGPSV2.SatelliteSystemStatusLowLevel getSatelliteSystemStatus(int satelliteSystem)

Returns the

  • satellite numbers list (up to 12 items)
  • fix value,
  • PDOP value,
  • HDOP value and
  • VDOP value

for a given satellite system. Currently GPS and GLONASS are supported, Galileo is not yet supported.

The GPS and GLONASS satellites have unique numbers and the satellite list gives the numbers of the satellites that are currently utilized. The number 0 is not a valid satellite number and can be ignored in the list.

The following constants are available for this function:

  • BrickletGPSV2.SATELLITE_SYSTEM_GPS = 0
  • BrickletGPSV2.SATELLITE_SYSTEM_GLONASS = 1
  • BrickletGPSV2.SATELLITE_SYSTEM_GALILEO = 2
  • BrickletGPSV2.FIX_NO_FIX = 1
  • BrickletGPSV2.FIX_2D_FIX = 2
  • BrickletGPSV2.FIX_3D_FIX = 3

The returned object has the public member variables int[] satelliteNumbers, int fix, int pdop, int hdop and int vdop.

public BrickletGPSV2.SatelliteStatus getSatelliteStatus(int satelliteSystem, int satelliteNumber)

Returns the current

  • elevation (0° - 90°),
  • azimuth (0° - 359°) and
  • SNR (0dB - 99dB)

for a given satellite and satellite system.

The satellite number here always goes from 1 to 32. For GLONASS it corresponds to the satellites 65-96.

Galileo is not yet supported.

The following constants are available for this function:

  • BrickletGPSV2.SATELLITE_SYSTEM_GPS = 0
  • BrickletGPSV2.SATELLITE_SYSTEM_GLONASS = 1
  • BrickletGPSV2.SATELLITE_SYSTEM_GALILEO = 2

The returned object has the public member variables int elevation, int azimuth and int snr.

Advanced Functions

public void restart(int restartType)

Restarts the GPS Bricklet, the following restart types are available:

Value Description
0 Hot start (use all available data in the NV store)
1 Warm start (don't use ephemeris at restart)
2 Cold start (don't use time, position, almanacs and ephemeris at restart)
3 Factory reset (clear all system/user configurations at restart)

The following constants are available for this function:

  • BrickletGPSV2.RESTART_TYPE_HOT_START = 0
  • BrickletGPSV2.RESTART_TYPE_WARM_START = 1
  • BrickletGPSV2.RESTART_TYPE_COLD_START = 2
  • BrickletGPSV2.RESTART_TYPE_FACTORY_RESET = 3
public void setFixLEDConfig(int config)

Sets the fix LED configuration. By default the LED shows if the Bricklet got a GPS fix yet. If a fix is established the LED turns on. If there is no fix then the LED is turned off.

You can also turn the LED permanently on/off, show a heartbeat or let it blink in sync with the PPS (pulse per second) output of the GPS module.

If the Bricklet is in bootloader mode, the LED is off.

The following constants are available for this function:

  • BrickletGPSV2.FIX_LED_CONFIG_OFF = 0
  • BrickletGPSV2.FIX_LED_CONFIG_ON = 1
  • BrickletGPSV2.FIX_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletGPSV2.FIX_LED_CONFIG_SHOW_FIX = 3
  • BrickletGPSV2.FIX_LED_CONFIG_SHOW_PPS = 4
public int getFixLEDConfig()

Returns the configuration as set by setFixLEDConfig()

The following constants are available for this function:

  • BrickletGPSV2.FIX_LED_CONFIG_OFF = 0
  • BrickletGPSV2.FIX_LED_CONFIG_ON = 1
  • BrickletGPSV2.FIX_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletGPSV2.FIX_LED_CONFIG_SHOW_FIX = 3
  • BrickletGPSV2.FIX_LED_CONFIG_SHOW_PPS = 4
public void setSBASConfig(int sbasConfig)

If SBAS is enabled, the position accuracy increases (if SBAS satellites are in view), but the update rate is limited to 5Hz. With SBAS disabled the update rate is increased to 10Hz.

By default SBAS is enabled and the update rate is 5Hz.

The following constants are available for this function:

  • BrickletGPSV2.SBAS_ENABLED = 0
  • BrickletGPSV2.SBAS_DISABLED = 1

New in version 2.0.2 (Plugin).

public int getSBASConfig()

Returns the SBAS configuration as set by setSBASConfig()

The following constants are available for this function:

  • BrickletGPSV2.SBAS_ENABLED = 0
  • BrickletGPSV2.SBAS_DISABLED = 1

New in version 2.0.2 (Plugin).

public int[] getAPIVersion()

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

public boolean getResponseExpected(int functionId)

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For listener configuration functions it is enabled by default too, but can be disabled by setResponseExpected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See setResponseExpected() for the list of function ID constants available for this function.

public void setResponseExpected(int functionId, boolean responseExpected)

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and listener configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BrickletGPSV2.FUNCTION_RESTART = 6
  • BrickletGPSV2.FUNCTION_SET_FIX_LED_CONFIG = 9
  • BrickletGPSV2.FUNCTION_SET_COORDINATES_CALLBACK_PERIOD = 11
  • BrickletGPSV2.FUNCTION_SET_STATUS_CALLBACK_PERIOD = 13
  • BrickletGPSV2.FUNCTION_SET_ALTITUDE_CALLBACK_PERIOD = 15
  • BrickletGPSV2.FUNCTION_SET_MOTION_CALLBACK_PERIOD = 17
  • BrickletGPSV2.FUNCTION_SET_DATE_TIME_CALLBACK_PERIOD = 19
  • BrickletGPSV2.FUNCTION_SET_SBAS_CONFIG = 27
  • BrickletGPSV2.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletGPSV2.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletGPSV2.FUNCTION_RESET = 243
  • BrickletGPSV2.FUNCTION_WRITE_UID = 248
public void setResponseExpectedAll(boolean responseExpected)

Changes the response expected flag for all setter and listener configuration functions of this device at once.

public BrickletGPSV2.SPITFPErrorCount getSPITFPErrorCount()

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

The returned object has the public member variables long errorCountAckChecksum, long errorCountMessageChecksum, long errorCountFrame and long errorCountOverflow.

public int setBootloaderMode(int mode)

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

  • BrickletGPSV2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletGPSV2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletGPSV2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletGPSV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletGPSV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BrickletGPSV2.BOOTLOADER_STATUS_OK = 0
  • BrickletGPSV2.BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletGPSV2.BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletGPSV2.BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletGPSV2.BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletGPSV2.BOOTLOADER_STATUS_CRC_MISMATCH = 5
public int getBootloaderMode()

Returns the current bootloader mode, see setBootloaderMode().

The following constants are available for this function:

  • BrickletGPSV2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletGPSV2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletGPSV2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletGPSV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletGPSV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
public void setWriteFirmwarePointer(long pointer)

Sets the firmware pointer for writeFirmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

public int writeFirmware(int[] data)

Writes 64 Bytes of firmware at the position as written by setWriteFirmwarePointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

public void setStatusLEDConfig(int config)

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

  • BrickletGPSV2.STATUS_LED_CONFIG_OFF = 0
  • BrickletGPSV2.STATUS_LED_CONFIG_ON = 1
  • BrickletGPSV2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletGPSV2.STATUS_LED_CONFIG_SHOW_STATUS = 3
public int getStatusLEDConfig()

Returns the configuration as set by setStatusLEDConfig()

The following constants are available for this function:

  • BrickletGPSV2.STATUS_LED_CONFIG_OFF = 0
  • BrickletGPSV2.STATUS_LED_CONFIG_ON = 1
  • BrickletGPSV2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletGPSV2.STATUS_LED_CONFIG_SHOW_STATUS = 3
public int getChipTemperature()

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

public void reset()

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

public void writeUID(long uid)

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

public long readUID()

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

public BrickletGPSV2.Identity getIdentity()

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

The returned object has the public member variables String uid, String connectedUid, char position, int[] hardwareVersion, int[] firmwareVersion and int deviceIdentifier.

Listener Configuration Functions

public void setCoordinatesCallbackPeriod(long period)

Sets the period in ms with which the CoordinatesListener listener is triggered periodically. A value of 0 turns the listener off.

The CoordinatesListener listener is only triggered if the coordinates changed since the last triggering.

The default value is 0.

public long getCoordinatesCallbackPeriod()

Returns the period as set by setCoordinatesCallbackPeriod().

public void setStatusCallbackPeriod(long period)

Sets the period in ms with which the StatusListener listener is triggered periodically. A value of 0 turns the listener off.

The StatusListener listener is only triggered if the status changed since the last triggering.

The default value is 0.

public long getStatusCallbackPeriod()

Returns the period as set by setStatusCallbackPeriod().

public void setAltitudeCallbackPeriod(long period)

Sets the period in ms with which the AltitudeListener listener is triggered periodically. A value of 0 turns the listener off.

The AltitudeListener listener is only triggered if the altitude changed since the last triggering.

The default value is 0.

public long getAltitudeCallbackPeriod()

Returns the period as set by setAltitudeCallbackPeriod().

public void setMotionCallbackPeriod(long period)

Sets the period in ms with which the MotionListener listener is triggered periodically. A value of 0 turns the listener off.

The MotionListener listener is only triggered if the motion changed since the last triggering.

The default value is 0.

public long getMotionCallbackPeriod()

Returns the period as set by setMotionCallbackPeriod().

public void setDateTimeCallbackPeriod(long period)

Sets the period in ms with which the DateTimeListener listener is triggered periodically. A value of 0 turns the listener off.

The DateTimeListener listener is only triggered if the date or time changed since the last triggering.

The default value is 0.

public long getDateTimeCallbackPeriod()

Returns the period as set by setDateTimeCallbackPeriod().

Listeners

Listeners can be registered to receive time critical or recurring data from the device. The registration is done with "add*Listener" functions of the device object.

The parameter is a listener class object, for example:

device.addExampleListener(new BrickletGPSV2.ExampleListener() {
    public void property(int value) {
        System.out.println("Value: " + value);
    }
});

The available listener classes with inherent methods to be overwritten are described below. It is possible to add several listeners and to remove them with the corresponding "remove*Listener" function.

Note

Using listeners for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

public class BrickletGPSV2.PulsePerSecondListener()

This listener can be added with the addPulsePerSecondListener() function. An added listener can be removed with the removePulsePerSecondListener() function.

public void pulsePerSecond()

This listener is triggered precisely once per second, see PPS.

The precision of two subsequent pulses will be skewed because of the latency in the USB/RS485/Ethernet connection. But in the long run this will be very precise. For example a count of 3600 pulses will take exactly 1 hour.

public class BrickletGPSV2.CoordinatesListener()

This listener can be added with the addCoordinatesListener() function. An added listener can be removed with the removeCoordinatesListener() function.

public void coordinates(long latitude, char ns, long longitude, char ew)

This listener is triggered periodically with the period that is set by setCoordinatesCallbackPeriod(). The parameters are the same as for getCoordinates().

The CoordinatesListener listener is only triggered if the coordinates changed since the last triggering and if there is currently a fix as indicated by getStatus().

public class BrickletGPSV2.StatusListener()

This listener can be added with the addStatusListener() function. An added listener can be removed with the removeStatusListener() function.

public void status(boolean hasFix, int satellitesView)

This listener is triggered periodically with the period that is set by setStatusCallbackPeriod(). The parameters are the same as for getStatus().

The StatusListener listener is only triggered if the status changed since the last triggering.

public class BrickletGPSV2.AltitudeListener()

This listener can be added with the addAltitudeListener() function. An added listener can be removed with the removeAltitudeListener() function.

public void altitude(int altitude, int geoidalSeparation)

This listener is triggered periodically with the period that is set by setAltitudeCallbackPeriod(). The parameters are the same as for getAltitude().

The AltitudeListener listener is only triggered if the altitude changed since the last triggering and if there is currently a fix as indicated by getStatus().

public class BrickletGPSV2.MotionListener()

This listener can be added with the addMotionListener() function. An added listener can be removed with the removeMotionListener() function.

public void motion(long course, long speed)

This listener is triggered periodically with the period that is set by setMotionCallbackPeriod(). The parameters are the same as for getMotion().

The MotionListener listener is only triggered if the motion changed since the last triggering and if there is currently a fix as indicated by getStatus().

public class BrickletGPSV2.DateTimeListener()

This listener can be added with the addDateTimeListener() function. An added listener can be removed with the removeDateTimeListener() function.

public void dateTime(long date, long time)

This listener is triggered periodically with the period that is set by setDateTimeCallbackPeriod(). The parameters are the same as for getDateTime().

The DateTimeListener listener is only triggered if the date or time changed since the last triggering.

Constants

public static final int BrickletGPSV2.DEVICE_IDENTIFIER

This constant is used to identify a GPS Bricklet 2.0.

The getIdentity() function and the EnumerateListener listener of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

public static final String BrickletGPSV2.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a GPS Bricklet 2.0.