Software / API Bindings / C/C++ for Microcontrollers / API Reference and Examples / Bricklets / Laser Range Finder Bricklet 2.0

C/C++ for Microcontrollers - Laser Range Finder Bricklet 2.0¶

This is the description of the C/C++ for Microcontrollers API bindings for the Laser Range Finder Bricklet 2.0. General information and technical specifications for the Laser Range Finder 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.

Examples¶

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

Simple¶

Download (example_simple.c)

// 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_laser_range_finder_v2.h"

void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);

static TF_LaserRangeFinderV2 lrf;

void example_setup(TF_HAL *hal) {
    // Create device object
    check(tf_laser_range_finder_v2_create(&lrf, NULL, hal), "create device object");

    // Turn laser on and wait 250ms for very first measurement to be ready
    check(tf_laser_range_finder_v2_set_enable(&lrf, true), "call set_enable");
    tf_hal_sleep_us(hal, 250 * 1000);

    // Get current distance
    int16_t distance;
    check(tf_laser_range_finder_v2_get_distance(&lrf, &distance), "get distance");

    tf_hal_printf("Distance: %I16d cm\n", distance);
}

void example_loop(TF_HAL *hal) {
    // Poll for callbacks
    tf_hal_callback_tick(hal, 0);
}

Callback¶

Download (example_callback.c)

// 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_laser_range_finder_v2.h"

void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);

// Callback function for distance callback
static void distance_handler(TF_LaserRangeFinderV2 *device, int16_t distance,
                             void *user_data) {
    (void)device; (void)user_data; // avoid unused parameter warning

    tf_hal_printf("Distance: %I16d cm\n", distance);
}

static TF_LaserRangeFinderV2 lrf;

void example_setup(TF_HAL *hal) {
    // Create device object
    check(tf_laser_range_finder_v2_create(&lrf, NULL, hal), "create device object");

    // Turn laser on and wait 250ms for very first measurement to be ready
    check(tf_laser_range_finder_v2_set_enable(&lrf, true), "call set_enable");
    tf_hal_sleep_us(hal, 250 * 1000);

    // Register distance callback to function distance_handler
    tf_laser_range_finder_v2_register_distance_callback(&lrf,
                                                        distance_handler,
                                                        NULL);

    // Set period for distance callback to 0.2s (200ms) without a threshold
    tf_laser_range_finder_v2_set_distance_callback_configuration(&lrf, 200, false, 'x', 0, 0);
}

void example_loop(TF_HAL *hal) {
    // Poll for callbacks
    tf_hal_callback_tick(hal, 0);
}

Threshold¶

Download (example_threshold.c)

// 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_laser_range_finder_v2.h"

void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);

// Callback function for distance callback
static void distance_handler(TF_LaserRangeFinderV2 *device, int16_t distance,
                             void *user_data) {
    (void)device; (void)user_data; // avoid unused parameter warning

    tf_hal_printf("Distance: %I16d cm\n", distance);
}

static TF_LaserRangeFinderV2 lrf;

void example_setup(TF_HAL *hal) {
    // Create device object
    check(tf_laser_range_finder_v2_create(&lrf, NULL, hal), "create device object");

    // Turn laser on and wait 250ms for very first measurement to be ready
    check(tf_laser_range_finder_v2_set_enable(&lrf, true), "call set_enable");
    tf_hal_sleep_us(hal, 250 * 1000);

    // Register distance callback to function distance_handler
    tf_laser_range_finder_v2_register_distance_callback(&lrf,
                                                        distance_handler,
                                                        NULL);

    // Configure threshold for distance "greater than 20 cm"
    // with a debounce period of 1s (1000ms)
    tf_laser_range_finder_v2_set_distance_callback_configuration(&lrf, 1000, false, '>', 20, 0);
}

void example_loop(TF_HAL *hal) {
    // Poll for callbacks
    tf_hal_callback_tick(hal, 0);
}

API¶

Most functions of the C/C++ bindings for microcontrollers return an error code (e_code).

Possible error codes are:

TF_E_OK = 0
TF_E_TIMEOUT = -1
TF_E_INVALID_PARAMETER = -2
TF_E_NOT_SUPPORTED = -3
TF_E_UNKNOWN_ERROR_CODE = -4
TF_E_STREAM_OUT_OF_SYNC = -5
TF_E_INVALID_CHAR_IN_UID = -6
TF_E_UID_TOO_LONG = -7
TF_E_UID_OVERFLOW = -8
TF_E_TOO_MANY_DEVICES = -9
TF_E_DEVICE_NOT_FOUND = -10
TF_E_WRONG_DEVICE_TYPE = -11
TF_E_LOCKED = -12
TF_E_PORT_NOT_FOUND = -13

(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.

Basic Functions¶

int tf_laser_range_finder_v2_create(TF_LaserRangeFinderV2 *laser_range_finder_v2, const char *uid_or_port_name, TF_HAL *hal)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * uid – Type: const char * hal – Type: TF_HAL *
Returns:	e_code – Type: int

Creates the device object laser_range_finder_v2 with the optional unique device ID or port name uid_or_port_name and adds it to the HAL hal:

TF_LaserRangeFinderV2 laser_range_finder_v2;
tf_laser_range_finder_v2_create(&laser_range_finder_v2, NULL, &hal);

Normally uid_or_port_name can stay NULL. For more details about this see section UID or Port Name.

int tf_laser_range_finder_v2_destroy(TF_LaserRangeFinderV2 *laser_range_finder_v2)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Returns:	e_code – Type: int

Removes the device object laser_range_finder_v2 from its HAL and destroys it. The device object cannot be used anymore afterwards.

int tf_laser_range_finder_v2_get_distance(TF_LaserRangeFinderV2 *laser_range_finder_v2, int16_t *ret_distance)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_distance – Type: int16_t, Unit: 1 cm, Range: [0 to 4000]
Returns:	e_code – Type: int

Returns the measured distance.

The laser has to be enabled, see tf_laser_range_finder_v2_set_enable().

If you want to get the value periodically, it is recommended to use the Distance callback. You can set the callback configuration with tf_laser_range_finder_v2_set_distance_callback_configuration().

int tf_laser_range_finder_v2_get_velocity(TF_LaserRangeFinderV2 *laser_range_finder_v2, int16_t *ret_velocity)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_velocity – Type: int16_t, Unit: 1 cm/s, Range: [-12800 to 12700]
Returns:	e_code – Type: int

Returns the measured velocity. The value has a range of -12800 to 12700 and is given in 1/100 m/s.

The velocity measurement only produces stables results if a fixed measurement rate (see tf_laser_range_finder_v2_set_configuration()) is configured. Also the laser has to be enabled, see tf_laser_range_finder_v2_set_enable().

If you want to get the value periodically, it is recommended to use the Velocity callback. You can set the callback configuration with tf_laser_range_finder_v2_set_velocity_callback_configuration().

int tf_laser_range_finder_v2_set_enable(TF_LaserRangeFinderV2 *laser_range_finder_v2, bool enable)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * enable – Type: bool, Default: false
Returns:	e_code – Type: int

Enables the laser of the LIDAR if set to true.

We recommend that you wait 250ms after enabling the laser before the first call of tf_laser_range_finder_v2_get_distance() to ensure stable measurements.

int tf_laser_range_finder_v2_get_enable(TF_LaserRangeFinderV2 *laser_range_finder_v2, bool *ret_enable)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_enable – Type: bool, Default: false
Returns:	e_code – Type: int

Returns the value as set by tf_laser_range_finder_v2_set_enable().

int tf_laser_range_finder_v2_set_configuration(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t acquisition_count, bool enable_quick_termination, uint8_t threshold_value, uint16_t measurement_frequency)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * acquisition_count – Type: uint8_t, Range: [1 to 255], Default: 128 enable_quick_termination – Type: bool, Default: false threshold_value – Type: uint8_t, Range: [0 to 255], Default: 0 measurement_frequency – Type: uint16_t, Unit: 1 Hz, Range: [0, 10 to 500], Default: 0
Returns:	e_code – Type: int

The Acquisition Count defines the number of times the Laser Range Finder Bricklet will integrate acquisitions to find a correlation record peak. With a higher count, the Bricklet can measure longer distances. With a lower count, the rate increases. The allowed values are 1-255.

If you set Enable Quick Termination to true, the distance measurement will be terminated early if a high peak was already detected. This means that a higher measurement rate can be achieved and long distances can be measured at the same time. However, the chance of false-positive distance measurements increases.

Normally the distance is calculated with a detection algorithm that uses peak value, signal strength and noise. You can however also define a fixed Threshold Value. Set this to a low value if you want to measure the distance to something that has very little reflection (e.g. glass) and set it to a high value if you want to measure the distance to something with a very high reflection (e.g. mirror). Set this to 0 to use the default algorithm. The other allowed values are 1-255.

Set the Measurement Frequency to force a fixed measurement rate. If set to 0, the Laser Range Finder Bricklet will use the optimal frequency according to the other configurations and the actual measured distance. Since the rate is not fixed in this case, the velocity measurement is not stable. For a stable velocity measurement you should set a fixed measurement frequency. The lower the frequency, the higher is the resolution of the calculated velocity. The allowed values are 10Hz-500Hz (and 0 to turn the fixed frequency off).

The default values for Acquisition Count, Enable Quick Termination, Threshold Value and Measurement Frequency are 128, false, 0 and 0.

int tf_laser_range_finder_v2_get_configuration(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_acquisition_count, bool *ret_enable_quick_termination, uint8_t *ret_threshold_value, uint16_t *ret_measurement_frequency)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_acquisition_count – Type: uint8_t, Range: [1 to 255], Default: 128 ret_enable_quick_termination – Type: bool, Default: false ret_threshold_value – Type: uint8_t, Range: [0 to 255], Default: 0 ret_measurement_frequency – Type: uint16_t, Unit: 1 Hz, Range: [0, 10 to 500], Default: 0
Returns:	e_code – Type: int

Returns the configuration as set by tf_laser_range_finder_v2_set_configuration().

int tf_laser_range_finder_v2_set_distance_led_config(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t config)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Configures the distance LED to be either turned off, turned on, blink in heartbeat mode or show the distance (brighter = object is nearer).

The following constants are available for this function:

For config:

TF_LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_OFF = 0
TF_LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_ON = 1
TF_LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_SHOW_DISTANCE = 3

int tf_laser_range_finder_v2_get_distance_led_config(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_config)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Returns the LED configuration as set by tf_laser_range_finder_v2_set_distance_led_config()

The following constants are available for this function:

For ret_config:

TF_LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_OFF = 0
TF_LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_ON = 1
TF_LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_SHOW_DISTANCE = 3

Advanced Functions¶

int tf_laser_range_finder_v2_set_moving_average(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t distance_average_length, uint8_t velocity_average_length)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * distance_average_length – Type: uint8_t, Range: [0 to 255], Default: 10 velocity_average_length – Type: uint8_t, Range: [0 to 255], Default: 10
Returns:	e_code – Type: int

Sets the length of a moving averaging for the distance and velocity.

Setting the length to 0 will turn the averaging completely off. With less averaging, there is more noise on the data.

int tf_laser_range_finder_v2_get_moving_average(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_distance_average_length, uint8_t *ret_velocity_average_length)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_distance_average_length – Type: uint8_t, Range: [0 to 255], Default: 10 ret_velocity_average_length – Type: uint8_t, Range: [0 to 255], Default: 10
Returns:	e_code – Type: int

Returns the length moving average as set by tf_laser_range_finder_v2_set_moving_average().

int tf_laser_range_finder_v2_set_offset_calibration(TF_LaserRangeFinderV2 *laser_range_finder_v2, int16_t offset)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * offset – Type: int16_t, Unit: 1 cm, Range: [-2¹⁵ to 28767]
Returns:	e_code – Type: int

The offset is added to the measured distance. It is saved in non-volatile memory, you only have to set it once.

The Bricklet comes with a per-sensor factory-calibrated offset value, you should not have to call this function.

If you want to re-calibrate the offset you first have to set it to 0. Calculate the offset by measuring the distance to a known distance and set it again.

int tf_laser_range_finder_v2_get_offset_calibration(TF_LaserRangeFinderV2 *laser_range_finder_v2, int16_t *ret_offset)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_offset – Type: int16_t, Unit: 1 cm, Range: [-2¹⁵ to 28767]
Returns:	e_code – Type: int

Returns the offset value as set by tf_laser_range_finder_v2_set_offset_calibration().

int tf_laser_range_finder_v2_get_spitfp_error_count(TF_LaserRangeFinderV2 *laser_range_finder_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:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
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 tf_laser_range_finder_v2_set_status_led_config(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t config)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * 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:

TF_LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_OFF = 0
TF_LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_ON = 1
TF_LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3

int tf_laser_range_finder_v2_get_status_led_config(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_config)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Returns the configuration as set by tf_laser_range_finder_v2_set_status_led_config()

The following constants are available for this function:

For ret_config:

TF_LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_OFF = 0
TF_LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_ON = 1
TF_LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3

int tf_laser_range_finder_v2_get_chip_temperature(TF_LaserRangeFinderV2 *laser_range_finder_v2, int16_t *ret_temperature)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
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 tf_laser_range_finder_v2_reset(TF_LaserRangeFinderV2 *laser_range_finder_v2)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
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 tf_laser_range_finder_v2_get_identity(TF_LaserRangeFinderV2 *laser_range_finder_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:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
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¶

int tf_laser_range_finder_v2_set_distance_callback_configuration(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint32_t period, bool value_has_to_change, char option, int16_t min, int16_t max)¶

Parameters:

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0 value_has_to_change – Type: bool, Default: false option – Type: char, Range: See constants, Default: 'x' min – Type: int16_t, Unit: 1 cm, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 max – Type: int16_t, Unit: 1 cm, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0
Returns:	e_code – Type: int

laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
value_has_to_change – Type: bool, Default: false
option – Type: char, Range: See constants, Default: 'x'
min – Type: int16_t, Unit: 1 cm, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0
max – Type: int16_t, Unit: 1 cm, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0

Returns:

e_code – Type: int

The period is the period with which the Distance callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the Distance callback.

The following options are possible:

Option	Description
'x'	Threshold is turned off
'o'	Threshold is triggered when the value is outside the min and max values
'i'	Threshold is triggered when the value is inside or equal to the min and max values
'<'	Threshold is triggered when the value is smaller than the min value (max is ignored)
'>'	Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The following constants are available for this function:

For option:

TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OFF = 'x'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_INSIDE = 'i'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_SMALLER = '<'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_GREATER = '>'

int tf_laser_range_finder_v2_get_distance_callback_configuration(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint32_t *ret_period, bool *ret_value_has_to_change, char *ret_option, int16_t *ret_min, int16_t *ret_max)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0 ret_value_has_to_change – Type: bool, Default: false ret_option – Type: char, Range: See constants, Default: 'x' ret_min – Type: int16_t, Unit: 1 cm, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 ret_max – Type: int16_t, Unit: 1 cm, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0
Returns:	e_code – Type: int

Returns the callback configuration as set by tf_laser_range_finder_v2_set_distance_callback_configuration().

The following constants are available for this function:

For ret_option:

TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OFF = 'x'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_INSIDE = 'i'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_SMALLER = '<'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_GREATER = '>'

int tf_laser_range_finder_v2_set_velocity_callback_configuration(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint32_t period, bool value_has_to_change, char option, int16_t min, int16_t max)¶

Parameters:

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0 value_has_to_change – Type: bool, Default: false option – Type: char, Range: See constants, Default: 'x' min – Type: int16_t, Unit: 1 cm/s, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 max – Type: int16_t, Unit: 1 cm/s, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0
Returns:	e_code – Type: int

laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
value_has_to_change – Type: bool, Default: false
option – Type: char, Range: See constants, Default: 'x'
min – Type: int16_t, Unit: 1 cm/s, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0
max – Type: int16_t, Unit: 1 cm/s, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0

Returns:

e_code – Type: int

The period is the period with which the Velocity callback is triggered periodically. A value of 0 turns the callback off.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the Velocity callback.

The following options are possible:

Option	Description
'x'	Threshold is turned off
'o'	Threshold is triggered when the value is outside the min and max values
'i'	Threshold is triggered when the value is inside or equal to the min and max values
'<'	Threshold is triggered when the value is smaller than the min value (max is ignored)
'>'	Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The following constants are available for this function:

For option:

TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OFF = 'x'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_INSIDE = 'i'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_SMALLER = '<'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_GREATER = '>'

int tf_laser_range_finder_v2_get_velocity_callback_configuration(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint32_t *ret_period, bool *ret_value_has_to_change, char *ret_option, int16_t *ret_min, int16_t *ret_max)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0 ret_value_has_to_change – Type: bool, Default: false ret_option – Type: char, Range: See constants, Default: 'x' ret_min – Type: int16_t, Unit: 1 cm/s, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 ret_max – Type: int16_t, Unit: 1 cm/s, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0
Returns:	e_code – Type: int

Returns the callback configuration as set by tf_laser_range_finder_v2_set_velocity_callback_configuration().

The following constants are available for this function:

For ret_option:

TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OFF = 'x'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_INSIDE = 'i'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_SMALLER = '<'
TF_LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_GREATER = '>'

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding tf_laser_range_finder_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_laser_range_finder_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.

int tf_laser_range_finder_v2_register_distance_callback(TF_LaserRangeFinderV2 *laser_range_finder_v2, TF_LaserRangeFinderV2_DistanceHandler handler, void *user_data)¶

void handler(TF_LaserRangeFinderV2 *laser_range_finder_v2, int16_t distance, void *user_data)

Callback Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * distance – Type: int16_t, Unit: 1 cm, Range: [0 to 4000] user_data – Type: void *

This callback is triggered periodically according to the configuration set by tf_laser_range_finder_v2_set_distance_callback_configuration().

The parameter is the same as tf_laser_range_finder_v2_get_distance().

int tf_laser_range_finder_v2_register_velocity_callback(TF_LaserRangeFinderV2 *laser_range_finder_v2, TF_LaserRangeFinderV2_VelocityHandler handler, void *user_data)¶

void handler(TF_LaserRangeFinderV2 *laser_range_finder_v2, int16_t velocity, void *user_data)

Callback Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * velocity – Type: int16_t, Unit: 1 cm/s, Range: [-12800 to 12700] user_data – Type: void *

This callback is triggered periodically according to the configuration set by tf_laser_range_finder_v2_set_velocity_callback_configuration().

The parameter is the same as tf_laser_range_finder_v2_get_velocity().

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object.

int tf_laser_range_finder_v2_get_response_expected(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t function_id, bool *ret_response_expected)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * 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 tf_laser_range_finder_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_LASER_RANGE_FINDER_V2_FUNCTION_SET_DISTANCE_CALLBACK_CONFIGURATION = 2
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_VELOCITY_CALLBACK_CONFIGURATION = 6
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_ENABLE = 9
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_CONFIGURATION = 11
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_MOVING_AVERAGE = 13
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_OFFSET_CALIBRATION = 15
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_DISTANCE_LED_CONFIG = 17
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
TF_LASER_RANGE_FINDER_V2_FUNCTION_RESET = 243
TF_LASER_RANGE_FINDER_V2_FUNCTION_WRITE_UID = 248

int tf_laser_range_finder_v2_set_response_expected(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t function_id, bool response_expected)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * 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:

TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_DISTANCE_CALLBACK_CONFIGURATION = 2
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_VELOCITY_CALLBACK_CONFIGURATION = 6
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_ENABLE = 9
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_CONFIGURATION = 11
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_MOVING_AVERAGE = 13
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_OFFSET_CALIBRATION = 15
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_DISTANCE_LED_CONFIG = 17
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
TF_LASER_RANGE_FINDER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
TF_LASER_RANGE_FINDER_V2_FUNCTION_RESET = 243
TF_LASER_RANGE_FINDER_V2_FUNCTION_WRITE_UID = 248

int tf_laser_range_finder_v2_set_response_expected_all(TF_LaserRangeFinderV2 *laser_range_finder_v2, bool response_expected)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * 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 tf_laser_range_finder_v2_set_bootloader_mode(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t mode, uint8_t *ret_status)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * 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:

TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE = 1
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For ret_status:

TF_LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_OK = 0
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5

int tf_laser_range_finder_v2_get_bootloader_mode(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_mode)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
Output Parameters:	ret_mode – Type: uint8_t, Range: See constants
Returns:	e_code – Type: int

Returns the current bootloader mode, see tf_laser_range_finder_v2_set_bootloader_mode().

The following constants are available for this function:

For ret_mode:

TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE = 1
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
TF_LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

int tf_laser_range_finder_v2_set_write_firmware_pointer(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint32_t pointer)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * pointer – Type: uint32_t, Unit: 1 B, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Sets the firmware pointer for tf_laser_range_finder_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.

int tf_laser_range_finder_v2_write_firmware(TF_LaserRangeFinderV2 *laser_range_finder_v2, const uint8_t data[64], uint8_t *ret_status)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * data – Type: const 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 tf_laser_range_finder_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.

int tf_laser_range_finder_v2_write_uid(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint32_t uid)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 * 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 tf_laser_range_finder_v2_read_uid(TF_LaserRangeFinderV2 *laser_range_finder_v2, uint32_t *ret_uid)¶

Parameters:	laser_range_finder_v2 – Type: TF_LaserRangeFinderV2 *
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¶

TF_LASER_RANGE_FINDER_V2_DEVICE_IDENTIFIER¶

This constant is used to identify a Laser Range Finder Bricklet 2.0.

The functions tf_laser_range_finder_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_LASER_RANGE_FINDER_V2_DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a Laser Range Finder Bricklet 2.0.