Software / API Bindings / C/C++ / API Reference and Examples / Bricklets / GPS Bricklet 3.0

C/C++ - GPS Bricklet 3.0¶

This is the description of the C/C++ API bindings for the GPS Bricklet 3.0. General information and technical specifications for the GPS Bricklet 3.0 are summarized in its hardware description.

An installation guide for the C/C++ API bindings is part of their general description.

Examples¶

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

Simple¶

Download (example_simple.c)

#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_gps_v3.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your GPS Bricklet 3.0

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    GPSV3 gps;
    gps_v3_create(&gps, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    // Get current coordinates
    uint32_t latitude, longitude; char ns, ew;
    if(gps_v3_get_coordinates(&gps, &latitude, &ns, &longitude, &ew) < 0) {
        fprintf(stderr, "Could not get coordinates, probably timeout\n");
        return 1;
    }

    printf("Latitude: %f °\n", latitude/1000000.0);
    printf("N/S: %c\n", ns);
    printf("Longitude: %f °\n", longitude/1000000.0);
    printf("E/W: %c\n", ew);

    printf("Press key to exit\n");
    getchar();
    gps_v3_destroy(&gps);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

Callback¶

Download (example_callback.c)

#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_gps_v3.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your GPS Bricklet 3.0

// Callback function for coordinates callback
void cb_coordinates(uint32_t latitude, char ns, uint32_t longitude, char ew,
                    void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Latitude: %f °\n", latitude/1000000.0);
    printf("N/S: %c\n", ns);
    printf("Longitude: %f °\n", longitude/1000000.0);
    printf("E/W: %c\n", ew);
    printf("\n");
}

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    GPSV3 gps;
    gps_v3_create(&gps, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    // Register coordinates callback to function cb_coordinates
    gps_v3_register_callback(&gps,
                             GPS_V3_CALLBACK_COORDINATES,
                             (void (*)(void))cb_coordinates,
                             NULL);

    // 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_v3_set_coordinates_callback_period(&gps, 1000);

    printf("Press key to exit\n");
    getchar();
    gps_v3_destroy(&gps);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

API¶

Most functions of the C/C++ bindings return an error code (e_code). Data returned from the device, when a getter is called, is handled via output parameters. These parameters are labeled with the ret_ prefix.

Possible error codes are:

E_OK = 0
E_TIMEOUT = -1
E_NO_STREAM_SOCKET = -2
E_HOSTNAME_INVALID = -3
E_NO_CONNECT = -4
E_NO_THREAD = -5
E_NOT_ADDED = -6 (unused since C/C++ bindings version 2.0.0)
E_ALREADY_CONNECTED = -7
E_NOT_CONNECTED = -8
E_INVALID_PARAMETER = -9
E_NOT_SUPPORTED = -10
E_UNKNOWN_ERROR_CODE = -11
E_STREAM_OUT_OF_SYNC = -12
E_INVALID_UID = -13
E_NON_ASCII_CHAR_IN_SECRET = -14
E_WRONG_DEVICE_TYPE = -15
E_DEVICE_REPLACED = -16
E_WRONG_RESPONSE_LENGTH = -17

as defined in ip_connection.h.

All functions listed below are thread-safe.

Basic Functions¶

void gps_v3_create(GPSV3 *gps_v3, const char *uid, IPConnection *ipcon)¶

Parameters:	gps_v3 – Type: GPSV3 * uid – Type: const char * ipcon – Type: IPConnection *

Creates the device object gps_v3 with the unique device ID uid and adds it to the IPConnection ipcon:

GPSV3 gps_v3;
gps_v3_create(&gps_v3, "YOUR_DEVICE_UID", &ipcon);

This device object can be used after the IP connection has been connected.

void gps_v3_destroy(GPSV3 *gps_v3)¶

Parameters:	gps_v3 – Type: GPSV3 *

Removes the device object gps_v3 from its IPConnection and destroys it. The device object cannot be used anymore afterwards.

int gps_v3_get_coordinates(GPSV3 *gps_v3, uint32_t *ret_latitude, char *ret_ns, uint32_t *ret_longitude, char *ret_ew)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_latitude – Type: uint32_t, Unit: 1/1000000 °, Range: [0 to 90000000] ret_ns – Type: char, Range: ['N', 'S'] ret_longitude – Type: uint32_t, Unit: 1/1000000 °, Range: [0 to 180000000] ret_ew – Type: char, Range: ['E', 'W']
Returns:	e_code – Type: int

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 gps_v3_get_status().

int gps_v3_get_status(GPSV3 *gps_v3, bool *ret_has_fix, uint8_t *ret_satellites_view)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_has_fix – Type: bool ret_satellites_view – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

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

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

int gps_v3_get_altitude(GPSV3 *gps_v3, int32_t *ret_altitude, int32_t *ret_geoidal_separation)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_altitude – Type: int32_t, Unit: 1 cm, Range: [-2³¹ to 2³¹ - 1] ret_geoidal_separation – Type: int32_t, Unit: 1 cm, Range: [-2³¹ to 2³¹ - 1]
Returns:	e_code – Type: int

Returns the current altitude and corresponding geoidal separation.

This data is only valid if there is currently a fix as indicated by gps_v3_get_status().

int gps_v3_get_motion(GPSV3 *gps_v3, uint32_t *ret_course, uint32_t *ret_speed)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_course – Type: uint32_t, Unit: 1/100 °, Range: [0 to 36000] ret_speed – Type: uint32_t, Unit: 1/100 km/h, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Returns the current course and speed. 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 gps_v3_get_status().

int gps_v3_get_date_time(GPSV3 *gps_v3, uint32_t *ret_date, uint32_t *ret_time)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_date – Type: uint32_t, Range: [10100 to 311299] ret_time – Type: uint32_t, Range: [0 to 235959999]
Returns:	e_code – Type: int

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 14.07.13 as date and 195923568 means 19:59:23.568 as time.

int gps_v3_get_satellite_system_status(GPSV3 *gps_v3, uint8_t satellite_system, uint8_t *ret_satellite_numbers, uint8_t *ret_satellite_numbers_length, uint8_t *ret_fix, uint16_t *ret_pdop, uint16_t *ret_hdop, uint16_t *ret_vdop)¶

Parameters:	gps_v3 – Type: GPSV3 * satellite_system – Type: uint8_t, Range: See constants
Output Parameters:	ret_satellite_numbers – Type: uint8_t , Range: [0 to 255] ret_satellite_numbers_length* – Type: uint8_t ret_fix – Type: uint8_t, Range: See constants ret_pdop – Type: uint16_t, Unit: 1/100, Range: [0 to 2¹⁶ - 1] ret_hdop – Type: uint16_t, Unit: 1/100, Range: [0 to 2¹⁶ - 1] ret_vdop – Type: uint16_t, Unit: 1/100, Range: [0 to 2¹⁶ - 1]
Returns:	e_code – Type: int

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:

For satellite_system:

GPS_V3_SATELLITE_SYSTEM_GPS = 0
GPS_V3_SATELLITE_SYSTEM_GLONASS = 1
GPS_V3_SATELLITE_SYSTEM_GALILEO = 2

For ret_fix:

GPS_V3_FIX_NO_FIX = 1
GPS_V3_FIX_2D_FIX = 2
GPS_V3_FIX_3D_FIX = 3

int gps_v3_get_satellite_status(GPSV3 *gps_v3, uint8_t satellite_system, uint8_t satellite_number, int16_t *ret_elevation, int16_t *ret_azimuth, int16_t *ret_snr)¶

Parameters:	gps_v3 – Type: GPSV3 * satellite_system – Type: uint8_t, Range: See constants satellite_number – Type: uint8_t, Range: [1 to 32]
Output Parameters:	ret_elevation – Type: int16_t, Unit: 1 °, Range: [0 to 90] ret_azimuth – Type: int16_t, Unit: 1 °, Range: [0 to 359] ret_snr – Type: int16_t, Unit: 1 dB, Range: [0 to 99]
Returns:	e_code – Type: int

Returns the current elevation, azimuth and SNR 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:

For satellite_system:

GPS_V3_SATELLITE_SYSTEM_GPS = 0
GPS_V3_SATELLITE_SYSTEM_GLONASS = 1
GPS_V3_SATELLITE_SYSTEM_GALILEO = 2

Advanced Functions¶

int gps_v3_restart(GPSV3 *gps_v3, uint8_t restart_type)¶

Parameters:	gps_v3 – Type: GPSV3 * restart_type – Type: uint8_t, Range: See constants
Returns:	e_code – Type: int

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:

For restart_type:

GPS_V3_RESTART_TYPE_HOT_START = 0
GPS_V3_RESTART_TYPE_WARM_START = 1
GPS_V3_RESTART_TYPE_COLD_START = 2
GPS_V3_RESTART_TYPE_FACTORY_RESET = 3

int gps_v3_set_fix_led_config(GPSV3 *gps_v3, uint8_t config)¶

Parameters:	gps_v3 – Type: GPSV3 * config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

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:

For config:

GPS_V3_FIX_LED_CONFIG_OFF = 0
GPS_V3_FIX_LED_CONFIG_ON = 1
GPS_V3_FIX_LED_CONFIG_SHOW_HEARTBEAT = 2
GPS_V3_FIX_LED_CONFIG_SHOW_FIX = 3
GPS_V3_FIX_LED_CONFIG_SHOW_PPS = 4

int gps_v3_get_fix_led_config(GPSV3 *gps_v3, uint8_t *ret_config)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Returns the configuration as set by gps_v3_set_fix_led_config()

The following constants are available for this function:

For ret_config:

GPS_V3_FIX_LED_CONFIG_OFF = 0
GPS_V3_FIX_LED_CONFIG_ON = 1
GPS_V3_FIX_LED_CONFIG_SHOW_HEARTBEAT = 2
GPS_V3_FIX_LED_CONFIG_SHOW_FIX = 3
GPS_V3_FIX_LED_CONFIG_SHOW_PPS = 4

int gps_v3_set_sbas_config(GPSV3 *gps_v3, uint8_t sbas_config)¶

Parameters:	gps_v3 – Type: GPSV3 * sbas_config – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

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.

The following constants are available for this function:

For sbas_config:

GPS_V3_SBAS_ENABLED = 0
GPS_V3_SBAS_DISABLED = 1

int gps_v3_get_sbas_config(GPSV3 *gps_v3, uint8_t *ret_sbas_config)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_sbas_config – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Returns the SBAS configuration as set by gps_v3_set_sbas_config()

The following constants are available for this function:

For ret_sbas_config:

GPS_V3_SBAS_ENABLED = 0
GPS_V3_SBAS_DISABLED = 1

int gps_v3_get_spitfp_error_count(GPSV3 *gps_v3, uint32_t *ret_error_count_ack_checksum, uint32_t *ret_error_count_message_checksum, uint32_t *ret_error_count_frame, uint32_t *ret_error_count_overflow)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_error_count_ack_checksum – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_message_checksum – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_frame – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_overflow – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

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.

int gps_v3_set_status_led_config(GPSV3 *gps_v3, uint8_t config)¶

Parameters:	gps_v3 – Type: GPSV3 * config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

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:

For config:

GPS_V3_STATUS_LED_CONFIG_OFF = 0
GPS_V3_STATUS_LED_CONFIG_ON = 1
GPS_V3_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
GPS_V3_STATUS_LED_CONFIG_SHOW_STATUS = 3

int gps_v3_get_status_led_config(GPSV3 *gps_v3, uint8_t *ret_config)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Returns the configuration as set by gps_v3_set_status_led_config()

The following constants are available for this function:

For ret_config:

GPS_V3_STATUS_LED_CONFIG_OFF = 0
GPS_V3_STATUS_LED_CONFIG_ON = 1
GPS_V3_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
GPS_V3_STATUS_LED_CONFIG_SHOW_STATUS = 3

int gps_v3_get_chip_temperature(GPSV3 *gps_v3, int16_t *ret_temperature)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_temperature – Type: int16_t, Unit: 1 °C, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	e_code – Type: int

Returns the temperature 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.

int gps_v3_reset(GPSV3 *gps_v3)¶

Parameters:	gps_v3 – Type: GPSV3 *
Returns:	e_code – Type: int

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!

int gps_v3_get_identity(GPSV3 *gps_v3, char ret_uid[8], char ret_connected_uid[8], char *ret_position, uint8_t ret_hardware_version[3], uint8_t ret_firmware_version[3], uint16_t *ret_device_identifier)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_uid – Type: char[8] ret_connected_uid – Type: char[8] ret_position – Type: char, Range: ['a' to 'h', 'z'] ret_hardware_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255] ret_firmware_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255] ret_device_identifier – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
Returns:	e_code – Type: int

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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

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

Callback Configuration Functions¶

void gps_v3_register_callback(GPSV3 *gps_v3, int16_t callback_id, void (*function)(void), void *user_data)¶

Parameters:	gps_v3 – Type: GPSV3 * callback_id – Type: int16_t function – Type: void ()(void) user_data* – Type: void *

Registers the given function with the given callback_id. The user_data will be passed as the last parameter to the function.

The available callback IDs with corresponding function signatures are listed below.

int gps_v3_set_coordinates_callback_period(GPSV3 *gps_v3, uint32_t period)¶

Parameters:	gps_v3 – Type: GPSV3 * period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Sets the period with which the GPS_V3_CALLBACK_COORDINATES callback is triggered periodically. A value of 0 turns the callback off.

The GPS_V3_CALLBACK_COORDINATES callback is only triggered if the coordinates changed since the last triggering.

int gps_v3_get_coordinates_callback_period(GPSV3 *gps_v3, uint32_t *ret_period)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Returns the period as set by gps_v3_set_coordinates_callback_period().

int gps_v3_set_status_callback_period(GPSV3 *gps_v3, uint32_t period)¶

Parameters:	gps_v3 – Type: GPSV3 * period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Sets the period with which the GPS_V3_CALLBACK_STATUS callback is triggered periodically. A value of 0 turns the callback off.

The GPS_V3_CALLBACK_STATUS callback is only triggered if the status changed since the last triggering.

int gps_v3_get_status_callback_period(GPSV3 *gps_v3, uint32_t *ret_period)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Returns the period as set by gps_v3_set_status_callback_period().

int gps_v3_set_altitude_callback_period(GPSV3 *gps_v3, uint32_t period)¶

Parameters:	gps_v3 – Type: GPSV3 * period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Sets the period with which the GPS_V3_CALLBACK_ALTITUDE callback is triggered periodically. A value of 0 turns the callback off.

The GPS_V3_CALLBACK_ALTITUDE callback is only triggered if the altitude changed since the last triggering.

int gps_v3_get_altitude_callback_period(GPSV3 *gps_v3, uint32_t *ret_period)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Returns the period as set by gps_v3_set_altitude_callback_period().

int gps_v3_set_motion_callback_period(GPSV3 *gps_v3, uint32_t period)¶

Parameters:	gps_v3 – Type: GPSV3 * period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Sets the period with which the GPS_V3_CALLBACK_MOTION callback is triggered periodically. A value of 0 turns the callback off.

The GPS_V3_CALLBACK_MOTION callback is only triggered if the motion changed since the last triggering.

int gps_v3_get_motion_callback_period(GPSV3 *gps_v3, uint32_t *ret_period)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Returns the period as set by gps_v3_set_motion_callback_period().

int gps_v3_set_date_time_callback_period(GPSV3 *gps_v3, uint32_t period)¶

Parameters:	gps_v3 – Type: GPSV3 * period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Sets the period with which the GPS_V3_CALLBACK_DATE_TIME callback is triggered periodically. A value of 0 turns the callback off.

The GPS_V3_CALLBACK_DATE_TIME callback is only triggered if the date or time changed since the last triggering.

int gps_v3_get_date_time_callback_period(GPSV3 *gps_v3, uint32_t *ret_period)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	e_code – Type: int

Returns the period as set by gps_v3_set_date_time_callback_period().

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the gps_v3_register_callback() function:

void my_callback(int value, void *user_data) {
    printf("Value: %d\n", value);
}

gps_v3_register_callback(&gps_v3,
                         GPS_V3_CALLBACK_EXAMPLE,
                         (void (*)(void))my_callback,
                         NULL);

The available constants with corresponding function signatures are described below.

Note

Using callbacks 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.

GPS_V3_CALLBACK_PULSE_PER_SECOND¶

void callback(void *user_data)

Callback Parameters:	user_data – Type: void *

This callback 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.

GPS_V3_CALLBACK_COORDINATES¶

void callback(uint32_t latitude, char ns, uint32_t longitude, char ew, void *user_data)

Callback Parameters:	latitude – Type: uint32_t, Unit: 1/1000000 °, Range: [0 to 90000000] ns – Type: char, Range: ['N', 'S'] longitude – Type: uint32_t, Unit: 1/1000000 °, Range: [0 to 180000000] ew – Type: char, Range: ['E', 'W'] user_data – Type: void *

This callback is triggered periodically with the period that is set by gps_v3_set_coordinates_callback_period(). The parameters are the same as for gps_v3_get_coordinates().

The GPS_V3_CALLBACK_COORDINATES callback is only triggered if the coordinates changed since the last triggering and if there is currently a fix as indicated by gps_v3_get_status().

GPS_V3_CALLBACK_STATUS¶

void callback(bool has_fix, uint8_t satellites_view, void *user_data)

Callback Parameters:	has_fix – Type: bool satellites_view – Type: uint8_t, Range: [0 to 255] user_data – Type: void *

This callback is triggered periodically with the period that is set by gps_v3_set_status_callback_period(). The parameters are the same as for gps_v3_get_status().

The GPS_V3_CALLBACK_STATUS callback is only triggered if the status changed since the last triggering.

GPS_V3_CALLBACK_ALTITUDE¶

void callback(int32_t altitude, int32_t geoidal_separation, void *user_data)

Callback Parameters:	altitude – Type: int32_t, Unit: 1 cm, Range: [-2³¹ to 2³¹ - 1] geoidal_separation – Type: int32_t, Unit: 1 cm, Range: [-2³¹ to 2³¹ - 1] user_data – Type: void *

This callback is triggered periodically with the period that is set by gps_v3_set_altitude_callback_period(). The parameters are the same as for gps_v3_get_altitude().

The GPS_V3_CALLBACK_ALTITUDE callback is only triggered if the altitude changed since the last triggering and if there is currently a fix as indicated by gps_v3_get_status().

GPS_V3_CALLBACK_MOTION¶

void callback(uint32_t course, uint32_t speed, void *user_data)

Callback Parameters:	course – Type: uint32_t, Unit: 1/100 °, Range: [0 to 36000] speed – Type: uint32_t, Unit: 1/100 km/h, Range: [0 to 2³² - 1] user_data – Type: void *

This callback is triggered periodically with the period that is set by gps_v3_set_motion_callback_period(). The parameters are the same as for gps_v3_get_motion().

The GPS_V3_CALLBACK_MOTION callback is only triggered if the motion changed since the last triggering and if there is currently a fix as indicated by gps_v3_get_status().

GPS_V3_CALLBACK_DATE_TIME¶

void callback(uint32_t date, uint32_t time, void *user_data)

Callback Parameters:	date – Type: uint32_t, Range: [10100 to 311299] time – Type: uint32_t, Range: [0 to 235959999] user_data – Type: void *

This callback is triggered periodically with the period that is set by gps_v3_set_date_time_callback_period(). The parameters are the same as for gps_v3_get_date_time().

The GPS_V3_CALLBACK_DATE_TIME callback is only triggered if the date or time changed since the last triggering.

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

int gps_v3_get_api_version(GPSV3 *gps_v3, uint8_t ret_api_version[3])¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_api_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

Returns the version of the API definition 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.

int gps_v3_get_response_expected(GPSV3 *gps_v3, uint8_t function_id, bool *ret_response_expected)¶

Parameters:	gps_v3 – Type: GPSV3 * function_id – Type: uint8_t, Range: See constants
Output Parameters:	ret_response_expected – Type: bool
Returns:	e_code – Type: int

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 callback configuration functions it is enabled by default too, but can be disabled by gps_v3_set_response_expected(). 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

GPS_V3_FUNCTION_RESTART = 6
GPS_V3_FUNCTION_SET_FIX_LED_CONFIG = 9
GPS_V3_FUNCTION_SET_COORDINATES_CALLBACK_PERIOD = 11
GPS_V3_FUNCTION_SET_STATUS_CALLBACK_PERIOD = 13
GPS_V3_FUNCTION_SET_ALTITUDE_CALLBACK_PERIOD = 15
GPS_V3_FUNCTION_SET_MOTION_CALLBACK_PERIOD = 17
GPS_V3_FUNCTION_SET_DATE_TIME_CALLBACK_PERIOD = 19
GPS_V3_FUNCTION_SET_SBAS_CONFIG = 27
GPS_V3_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
GPS_V3_FUNCTION_SET_STATUS_LED_CONFIG = 239
GPS_V3_FUNCTION_RESET = 243
GPS_V3_FUNCTION_WRITE_UID = 248

int gps_v3_set_response_expected(GPSV3 *gps_v3, uint8_t function_id, bool response_expected)¶

Parameters:	gps_v3 – Type: GPSV3 * function_id – Type: uint8_t, Range: See constants response_expected – Type: bool
Returns:	e_code – Type: int

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 callback configuration functions (default value: true). For getter functions it is always enabled.

The following constants are available for this function:

For function_id:

GPS_V3_FUNCTION_RESTART = 6
GPS_V3_FUNCTION_SET_FIX_LED_CONFIG = 9
GPS_V3_FUNCTION_SET_COORDINATES_CALLBACK_PERIOD = 11
GPS_V3_FUNCTION_SET_STATUS_CALLBACK_PERIOD = 13
GPS_V3_FUNCTION_SET_ALTITUDE_CALLBACK_PERIOD = 15
GPS_V3_FUNCTION_SET_MOTION_CALLBACK_PERIOD = 17
GPS_V3_FUNCTION_SET_DATE_TIME_CALLBACK_PERIOD = 19
GPS_V3_FUNCTION_SET_SBAS_CONFIG = 27
GPS_V3_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
GPS_V3_FUNCTION_SET_STATUS_LED_CONFIG = 239
GPS_V3_FUNCTION_RESET = 243
GPS_V3_FUNCTION_WRITE_UID = 248

int gps_v3_set_response_expected_all(GPSV3 *gps_v3, bool response_expected)¶

Parameters:	gps_v3 – Type: GPSV3 * response_expected – Type: bool
Returns:	e_code – Type: int

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

Internal Functions¶

Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.

int gps_v3_set_bootloader_mode(GPSV3 *gps_v3, uint8_t mode, uint8_t *ret_status)¶

Parameters:	gps_v3 – Type: GPSV3 * mode – Type: uint8_t, Range: See constants
Output Parameters:	ret_status – Type: uint8_t, Range: See constants
Returns:	e_code – Type: int

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:

For mode:

GPS_V3_BOOTLOADER_MODE_BOOTLOADER = 0
GPS_V3_BOOTLOADER_MODE_FIRMWARE = 1
GPS_V3_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
GPS_V3_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
GPS_V3_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For ret_status:

GPS_V3_BOOTLOADER_STATUS_OK = 0
GPS_V3_BOOTLOADER_STATUS_INVALID_MODE = 1
GPS_V3_BOOTLOADER_STATUS_NO_CHANGE = 2
GPS_V3_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
GPS_V3_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
GPS_V3_BOOTLOADER_STATUS_CRC_MISMATCH = 5

int gps_v3_get_bootloader_mode(GPSV3 *gps_v3, uint8_t *ret_mode)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_mode – Type: uint8_t, Range: See constants
Returns:	e_code – Type: int

Returns the current bootloader mode, see gps_v3_set_bootloader_mode().

The following constants are available for this function:

For ret_mode:

GPS_V3_BOOTLOADER_MODE_BOOTLOADER = 0
GPS_V3_BOOTLOADER_MODE_FIRMWARE = 1
GPS_V3_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
GPS_V3_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
GPS_V3_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

int gps_v3_set_write_firmware_pointer(GPSV3 *gps_v3, uint32_t pointer)¶

Parameters:	gps_v3 – Type: GPSV3 * pointer – Type: uint32_t, Unit: 1 B, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Sets the firmware pointer for gps_v3_write_firmware(). 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.

int gps_v3_write_firmware(GPSV3 *gps_v3, uint8_t data[64], uint8_t *ret_status)¶

Parameters:	gps_v3 – Type: GPSV3 * data – Type: uint8_t[64], Range: [0 to 255]
Output Parameters:	ret_status – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

Writes 64 Bytes of firmware at the position as written by gps_v3_set_write_firmware_pointer() 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.

int gps_v3_write_uid(GPSV3 *gps_v3, uint32_t uid)¶

Parameters:	gps_v3 – Type: GPSV3 * uid – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

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.

int gps_v3_read_uid(GPSV3 *gps_v3, uint32_t *ret_uid)¶

Parameters:	gps_v3 – Type: GPSV3 *
Output Parameters:	ret_uid – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

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

Constants¶

GPS_V3_DEVICE_IDENTIFIER¶

This constant is used to identify a GPS Bricklet 3.0.

The gps_v3_get_identity() function and the IPCON_CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

GPS_V3_DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a GPS Bricklet 3.0.