This is the description of the C/C++ for Microcontrollers 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 C/C++ for Microcontrollers API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
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 | // This example is not self-contained.
// It requires usage of the example driver specific to your platform.
// See the HAL documentation.
#include "src/bindings/hal_common.h"
#include "src/bindings/bricklet_gps_v2.h"
void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);
static TF_GPSV2 gps;
void example_setup(TF_HAL *hal) {
// Create device object
check(tf_gps_v2_create(&gps, NULL, hal), "create device object");
// Get current coordinates
uint32_t latitude, longitude; char ns, ew;
check(tf_gps_v2_get_coordinates(&gps, &latitude, &ns, &longitude,
&ew), "get coordinates");
tf_hal_printf("Latitude: %d 1/%d °\n", latitude, 1000000);
tf_hal_printf("N/S: %c\n", ns);
tf_hal_printf("Longitude: %d 1/%d °\n", longitude, 1000000);
tf_hal_printf("E/W: %c\n", ew);
}
void example_loop(TF_HAL *hal) {
// Poll for callbacks
tf_hal_callback_tick(hal, 0);
}
|
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 40 41 42 43 44 | // This example is not self-contained.
// It requires usage of the example driver specific to your platform.
// See the HAL documentation.
#include "src/bindings/hal_common.h"
#include "src/bindings/bricklet_gps_v2.h"
void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);
// Callback function for coordinates callback
static void coordinates_handler(TF_GPSV2 *device, uint32_t latitude, char ns,
uint32_t longitude, char ew, void *user_data) {
(void)device; (void)user_data; // avoid unused parameter warning
tf_hal_printf("Latitude: %d 1/%d °\n", latitude, 1000000);
tf_hal_printf("N/S: %c\n", ns);
tf_hal_printf("Longitude: %d 1/%d °\n", longitude, 1000000);
tf_hal_printf("E/W: %c\n", ew);
tf_hal_printf("\n");
}
static TF_GPSV2 gps;
void example_setup(TF_HAL *hal) {
// Create device object
check(tf_gps_v2_create(&gps, NULL, hal), "create device object");
// Register coordinates callback to function coordinates_handler
tf_gps_v2_register_coordinates_callback(&gps,
coordinates_handler,
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!
check(tf_gps_v2_set_coordinates_callback_period(&gps, 1000), "set coordinates callback period");
}
void example_loop(TF_HAL *hal) {
// Poll for callbacks
tf_hal_callback_tick(hal, 0);
}
|
Most functions of the C/C++ bindings for microcontrollers return an error code
(e_code
).
Possible error codes are:
(as defined in errors.h
) as well as the errors returned from
the hardware abstraction layer (HAL) that is used.
Use :cpp:func`tf_hal_strerror` (defined in the HAL's header file) to get an error string for an error code.
Data returned from the device, when a getter is called,
is handled via output parameters. These parameters are labeled with the
ret_
prefix. The bindings will not write to an output parameter if NULL or nullptr
is passed. This can be used to ignore outputs that you are not interested in.
None of the functions listed below are thread-safe. See the API bindings description for details.
tf_gps_v2_create
(TF_GPSV2 *gps_v2, const char *uid_or_port_name, TF_HAL *hal)¶Parameters: |
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Returns: |
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Creates the device object gps_v2
with the optional unique device ID or port name
uid_or_port_name
and adds it to the HAL hal
:
TF_GPSV2 gps_v2;
tf_gps_v2_create(&gps_v2, NULL, &hal);
Normally uid_or_port_name
can stay NULL
. For more details about this
see section UID or Port Name.
tf_gps_v2_destroy
(TF_GPSV2 *gps_v2)¶Parameters: |
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Returns: |
|
Removes the device object gps_v2
from its HAL and destroys it.
The device object cannot be used anymore afterwards.
tf_gps_v2_get_coordinates
(TF_GPSV2 *gps_v2, uint32_t *ret_latitude, char *ret_ns, uint32_t *ret_longitude, char *ret_ew)¶Parameters: |
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Output Parameters: |
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Returns: |
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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
tf_gps_v2_get_status()
.
tf_gps_v2_get_status
(TF_GPSV2 *gps_v2, bool *ret_has_fix, uint8_t *ret_satellites_view)¶Parameters: |
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Output Parameters: |
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Returns: |
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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.
tf_gps_v2_get_altitude
(TF_GPSV2 *gps_v2, int32_t *ret_altitude, int32_t *ret_geoidal_separation)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the current altitude and corresponding geoidal separation.
This data is only valid if there is currently a fix as indicated by
tf_gps_v2_get_status()
.
tf_gps_v2_get_motion
(TF_GPSV2 *gps_v2, uint32_t *ret_course, uint32_t *ret_speed)¶Parameters: |
|
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Output Parameters: |
|
Returns: |
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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
tf_gps_v2_get_status()
.
tf_gps_v2_get_date_time
(TF_GPSV2 *gps_v2, uint32_t *ret_date, uint32_t *ret_time)¶Parameters: |
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Output Parameters: |
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Returns: |
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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.
tf_gps_v2_get_satellite_system_status
(TF_GPSV2 *gps_v2, 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: |
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Output Parameters: |
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Returns: |
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Returns the
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:
For ret_fix:
tf_gps_v2_get_satellite_status
(TF_GPSV2 *gps_v2, uint8_t satellite_system, uint8_t satellite_number, int16_t *ret_elevation, int16_t *ret_azimuth, int16_t *ret_snr)¶Parameters: |
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Output Parameters: |
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Returns: |
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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:
tf_gps_v2_restart
(TF_GPSV2 *gps_v2, uint8_t restart_type)¶Parameters: |
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Returns: |
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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:
tf_gps_v2_set_fix_led_config
(TF_GPSV2 *gps_v2, uint8_t config)¶Parameters: |
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Returns: |
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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:
tf_gps_v2_get_fix_led_config
(TF_GPSV2 *gps_v2, uint8_t *ret_config)¶Parameters: |
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Output Parameters: |
|
Returns: |
|
Returns the configuration as set by tf_gps_v2_set_fix_led_config()
The following constants are available for this function:
For ret_config:
tf_gps_v2_set_sbas_config
(TF_GPSV2 *gps_v2, uint8_t sbas_config)¶Parameters: |
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Returns: |
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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:
New in version 2.0.2 (Plugin).
tf_gps_v2_get_sbas_config
(TF_GPSV2 *gps_v2, uint8_t *ret_sbas_config)¶Parameters: |
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Output Parameters: |
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Returns: |
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Returns the SBAS configuration as set by tf_gps_v2_set_sbas_config()
The following constants are available for this function:
For ret_sbas_config:
New in version 2.0.2 (Plugin).
tf_gps_v2_get_spitfp_error_count
(TF_GPSV2 *gps_v2, 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: |
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Output Parameters: |
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Returns: |
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Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
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.
tf_gps_v2_set_status_led_config
(TF_GPSV2 *gps_v2, uint8_t config)¶Parameters: |
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Returns: |
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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:
tf_gps_v2_get_status_led_config
(TF_GPSV2 *gps_v2, uint8_t *ret_config)¶Parameters: |
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Output Parameters: |
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Returns: |
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Returns the configuration as set by tf_gps_v2_set_status_led_config()
The following constants are available for this function:
For ret_config:
tf_gps_v2_get_chip_temperature
(TF_GPSV2 *gps_v2, int16_t *ret_temperature)¶Parameters: |
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Output Parameters: |
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Returns: |
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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.
tf_gps_v2_reset
(TF_GPSV2 *gps_v2)¶Parameters: |
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Returns: |
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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!
tf_gps_v2_get_identity
(TF_GPSV2 *gps_v2, 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: |
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Output Parameters: |
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Returns: |
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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.
tf_gps_v2_set_coordinates_callback_period
(TF_GPSV2 *gps_v2, uint32_t period)¶Parameters: |
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Returns: |
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Sets the period with which the Coordinates
callback is triggered
periodically. A value of 0 turns the callback off.
The Coordinates
callback is only triggered if the coordinates changed
since the last triggering.
tf_gps_v2_get_coordinates_callback_period
(TF_GPSV2 *gps_v2, uint32_t *ret_period)¶Parameters: |
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Output Parameters: |
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Returns: |
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Returns the period as set by tf_gps_v2_set_coordinates_callback_period()
.
tf_gps_v2_set_status_callback_period
(TF_GPSV2 *gps_v2, uint32_t period)¶Parameters: |
|
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Returns: |
|
Sets the period with which the Status
callback is triggered
periodically. A value of 0 turns the callback off.
The Status
callback is only triggered if the status changed since the
last triggering.
tf_gps_v2_get_status_callback_period
(TF_GPSV2 *gps_v2, uint32_t *ret_period)¶Parameters: |
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---|---|
Output Parameters: |
|
Returns: |
|
Returns the period as set by tf_gps_v2_set_status_callback_period()
.
tf_gps_v2_set_altitude_callback_period
(TF_GPSV2 *gps_v2, uint32_t period)¶Parameters: |
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Returns: |
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Sets the period with which the Altitude
callback is triggered
periodically. A value of 0 turns the callback off.
The Altitude
callback is only triggered if the altitude changed since the
last triggering.
tf_gps_v2_get_altitude_callback_period
(TF_GPSV2 *gps_v2, uint32_t *ret_period)¶Parameters: |
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Output Parameters: |
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Returns: |
|
Returns the period as set by tf_gps_v2_set_altitude_callback_period()
.
tf_gps_v2_set_motion_callback_period
(TF_GPSV2 *gps_v2, uint32_t period)¶Parameters: |
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Returns: |
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Sets the period with which the Motion
callback is triggered
periodically. A value of 0 turns the callback off.
The Motion
callback is only triggered if the motion changed since the
last triggering.
tf_gps_v2_get_motion_callback_period
(TF_GPSV2 *gps_v2, uint32_t *ret_period)¶Parameters: |
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---|---|
Output Parameters: |
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Returns: |
|
Returns the period as set by tf_gps_v2_set_motion_callback_period()
.
tf_gps_v2_set_date_time_callback_period
(TF_GPSV2 *gps_v2, uint32_t period)¶Parameters: |
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Returns: |
|
Sets the period with which the Date Time
callback is triggered
periodically. A value of 0 turns the callback off.
The Date Time
callback is only triggered if the date or time changed
since the last triggering.
tf_gps_v2_get_date_time_callback_period
(TF_GPSV2 *gps_v2, uint32_t *ret_period)¶Parameters: |
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---|---|
Output Parameters: |
|
Returns: |
|
Returns the period as set by tf_gps_v2_set_date_time_callback_period()
.
Callbacks can be registered to receive time critical or recurring data from the
device. The registration is done with the corresponding tf_gps_v2_register_*_callback
function.
The user_data
passed to the registration function as well as the device that triggered the callback are
passed to the registered callback handler.
Only one handler can be registered to a callback at the same time.
To deregister a callback, call the tf_gps_v2_register_*_callback
function
with NULL as handler.
Note
Using callbacks for recurring events is preferred compared to using getters. Polling for a callback requires writing one byte only. See here Optimizing Performance.
Warning
Calling bindings function from inside a callback handler is not allowed. See here Thread safety.
tf_gps_v2_register_pulse_per_second_callback
(TF_GPSV2 *gps_v2, TF_GPSV2_PulsePerSecondHandler handler, void *user_data)¶void handler(TF_GPSV2 *gps_v2, void *user_data)
Callback Parameters: |
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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.
tf_gps_v2_register_coordinates_callback
(TF_GPSV2 *gps_v2, TF_GPSV2_CoordinatesHandler handler, void *user_data)¶void handler(TF_GPSV2 *gps_v2, uint32_t latitude, char ns, uint32_t longitude, char ew, void *user_data)
Callback Parameters: |
|
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This callback is triggered periodically with the period that is set by
tf_gps_v2_set_coordinates_callback_period()
. The parameters are the same
as for tf_gps_v2_get_coordinates()
.
The Coordinates
callback is only triggered if the coordinates changed
since the last triggering and if there is currently a fix as indicated by
tf_gps_v2_get_status()
.
tf_gps_v2_register_status_callback
(TF_GPSV2 *gps_v2, TF_GPSV2_StatusHandler handler, void *user_data)¶void handler(TF_GPSV2 *gps_v2, bool has_fix, uint8_t satellites_view, void *user_data)
Callback Parameters: |
|
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This callback is triggered periodically with the period that is set by
tf_gps_v2_set_status_callback_period()
. The parameters are the same
as for tf_gps_v2_get_status()
.
The Status
callback is only triggered if the status changed since the
last triggering.
tf_gps_v2_register_altitude_callback
(TF_GPSV2 *gps_v2, TF_GPSV2_AltitudeHandler handler, void *user_data)¶void handler(TF_GPSV2 *gps_v2, int32_t altitude, int32_t geoidal_separation, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
tf_gps_v2_set_altitude_callback_period()
. The parameters are the same
as for tf_gps_v2_get_altitude()
.
The Altitude
callback is only triggered if the altitude changed since the
last triggering and if there is currently a fix as indicated by
tf_gps_v2_get_status()
.
tf_gps_v2_register_motion_callback
(TF_GPSV2 *gps_v2, TF_GPSV2_MotionHandler handler, void *user_data)¶void handler(TF_GPSV2 *gps_v2, uint32_t course, uint32_t speed, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
tf_gps_v2_set_motion_callback_period()
. The parameters are the same
as for tf_gps_v2_get_motion()
.
The Motion
callback is only triggered if the motion changed since the
last triggering and if there is currently a fix as indicated by
tf_gps_v2_get_status()
.
tf_gps_v2_register_date_time_callback
(TF_GPSV2 *gps_v2, TF_GPSV2_DateTimeHandler handler, void *user_data)¶void handler(TF_GPSV2 *gps_v2, uint32_t date, uint32_t time, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
tf_gps_v2_set_date_time_callback_period()
. The parameters are the same
as for tf_gps_v2_get_date_time()
.
The Date Time
callback is only triggered if the date or time changed
since the last triggering.
Virtual functions don't communicate with the device itself, but operate only on the API bindings device object.
tf_gps_v2_get_response_expected
(TF_GPSV2 *gps_v2, uint8_t function_id, bool *ret_response_expected)¶Parameters: |
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Output Parameters: |
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Returns: |
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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
tf_gps_v2_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:
tf_gps_v2_set_response_expected
(TF_GPSV2 *gps_v2, uint8_t function_id, bool response_expected)¶Parameters: |
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Returns: |
|
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.
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:
tf_gps_v2_set_response_expected_all
(TF_GPSV2 *gps_v2, bool response_expected)¶Parameters: |
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Returns: |
|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
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.
tf_gps_v2_set_bootloader_mode
(TF_GPSV2 *gps_v2, uint8_t mode, uint8_t *ret_status)¶Parameters: |
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Output Parameters: |
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Returns: |
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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:
For ret_status:
tf_gps_v2_get_bootloader_mode
(TF_GPSV2 *gps_v2, uint8_t *ret_mode)¶Parameters: |
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---|---|
Output Parameters: |
|
Returns: |
|
Returns the current bootloader mode, see tf_gps_v2_set_bootloader_mode()
.
The following constants are available for this function:
For ret_mode:
tf_gps_v2_set_write_firmware_pointer
(TF_GPSV2 *gps_v2, uint32_t pointer)¶Parameters: |
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Returns: |
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Sets the firmware pointer for tf_gps_v2_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.
tf_gps_v2_write_firmware
(TF_GPSV2 *gps_v2, const uint8_t data[64], uint8_t *ret_status)¶Parameters: |
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Output Parameters: |
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Returns: |
|
Writes 64 Bytes of firmware at the position as written by
tf_gps_v2_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.
tf_gps_v2_write_uid
(TF_GPSV2 *gps_v2, uint32_t uid)¶Parameters: |
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Returns: |
|
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.
tf_gps_v2_read_uid
(TF_GPSV2 *gps_v2, uint32_t *ret_uid)¶Parameters: |
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Output Parameters: |
|
Returns: |
|
Returns the current UID as an integer. Encode as Base58 to get the usual string version.
TF_GPS_V2_DEVICE_IDENTIFIER
¶This constant is used to identify a GPS Bricklet 2.0.
The functions tf_gps_v2_get_identity()
and tf_hal_get_device_info()
have a device_identifier
output parameter to specify
the Brick's or Bricklet's type.
TF_GPS_V2_DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a GPS Bricklet 2.0.