C/C++ - Laser Range Finder Bricklet 2.0

This is the description of the C/C++ 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++ API bindings is part of their general description.

Examples

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

API

Every function of the C/C++ bindings returns an integer which describes 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.

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

as defined in ip_connection.h.

All functions listed below are thread-safe.

Basic Functions

void laser_range_finder_v2_create(LaserRangeFinderV2 *laser_range_finder_v2, const char *uid, IPConnection *ipcon)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • uid – Type: const char *
  • ipcon – Type: IPConnection *

Creates the device object laser_range_finder_v2 with the unique device ID uid and adds it to the IPConnection ipcon:

LaserRangeFinderV2 laser_range_finder_v2;
laser_range_finder_v2_create(&laser_range_finder_v2, "YOUR_DEVICE_UID", &ipcon);

This device object can be used after the IP connection has been connected (see examples above).

void laser_range_finder_v2_destroy(LaserRangeFinderV2 *laser_range_finder_v2)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *

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

int laser_range_finder_v2_get_distance(LaserRangeFinderV2 *laser_range_finder_v2, int16_t *ret_distance)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_distance – Type: int16_t, Unit: 1 cm, Range: [0 to 4000]
Returns:
  • error_code – Type: int

Returns the measured distance.

The laser has to be enabled, see laser_range_finder_v2_set_enable().

If you want to get the value periodically, it is recommended to use the LASER_RANGE_FINDER_V2_CALLBACK_DISTANCE callback. You can set the callback configuration with laser_range_finder_v2_set_distance_callback_configuration().

int laser_range_finder_v2_get_velocity(LaserRangeFinderV2 *laser_range_finder_v2, int16_t *ret_velocity)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_velocity – Type: int16_t, Unit: 1 cm/s, Range: [-12800 to 12700]
Returns:
  • error_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 laser_range_finder_v2_set_configuration()) is configured. Also the laser has to be enabled, see laser_range_finder_v2_set_enable().

If you want to get the value periodically, it is recommended to use the LASER_RANGE_FINDER_V2_CALLBACK_VELOCITY callback. You can set the callback configuration with laser_range_finder_v2_set_velocity_callback_configuration().

int laser_range_finder_v2_set_enable(LaserRangeFinderV2 *laser_range_finder_v2, bool enable)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • enable – Type: bool, Default: false
Returns:
  • error_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 laser_range_finder_v2_get_distance() to ensure stable measurements.

int laser_range_finder_v2_get_enable(LaserRangeFinderV2 *laser_range_finder_v2, bool *ret_enable)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_enable – Type: bool, Default: false
Returns:
  • error_code – Type: int

Returns the value as set by laser_range_finder_v2_set_enable().

int laser_range_finder_v2_set_configuration(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: 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:
  • error_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 laser_range_finder_v2_get_configuration(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: 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:
  • error_code – Type: int

Returns the configuration as set by laser_range_finder_v2_set_configuration().

int laser_range_finder_v2_set_distance_led_config(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t config)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • config – Type: uint8_t, Range: See constants, Default: 3
Returns:
  • error_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:

  • LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_OFF = 0
  • LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_ON = 1
  • LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_SHOW_HEARTBEAT = 2
  • LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_SHOW_DISTANCE = 3
int laser_range_finder_v2_get_distance_led_config(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_config)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:
  • error_code – Type: int

Returns the LED configuration as set by laser_range_finder_v2_set_distance_led_config()

The following constants are available for this function:

For ret_config:

  • LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_OFF = 0
  • LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_ON = 1
  • LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_SHOW_HEARTBEAT = 2
  • LASER_RANGE_FINDER_V2_DISTANCE_LED_CONFIG_SHOW_DISTANCE = 3

Advanced Functions

int laser_range_finder_v2_set_moving_average(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t distance_average_length, uint8_t velocity_average_length)
Parameters:
  • laser_range_finder_v2 – Type: 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:
  • error_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 laser_range_finder_v2_get_moving_average(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_distance_average_length, uint8_t *ret_velocity_average_length)
Parameters:
  • laser_range_finder_v2 – Type: 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:
  • error_code – Type: int

Returns the length moving average as set by laser_range_finder_v2_set_moving_average().

int laser_range_finder_v2_set_offset_calibration(LaserRangeFinderV2 *laser_range_finder_v2, int16_t offset)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • offset – Type: int16_t, Unit: 1 cm, Range: [-215 to 28767]
Returns:
  • error_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 laser_range_finder_v2_get_offset_calibration(LaserRangeFinderV2 *laser_range_finder_v2, int16_t *ret_offset)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_offset – Type: int16_t, Unit: 1 cm, Range: [-215 to 28767]
Returns:
  • error_code – Type: int

Returns the offset value as set by laser_range_finder_v2_set_offset_calibration().

int laser_range_finder_v2_get_spitfp_error_count(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: 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:
  • error_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 laser_range_finder_v2_set_bootloader_mode(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t mode, uint8_t *ret_status)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • mode – Type: uint8_t, Range: See constants
Output Parameters:
  • ret_status – Type: uint8_t, Range: See constants
Returns:
  • error_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:

  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For ret_status:

  • LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_OK = 0
  • LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
  • LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
  • LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • LASER_RANGE_FINDER_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
int laser_range_finder_v2_get_bootloader_mode(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_mode)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_mode – Type: uint8_t, Range: See constants
Returns:
  • error_code – Type: int

Returns the current bootloader mode, see laser_range_finder_v2_set_bootloader_mode().

The following constants are available for this function:

For ret_mode:

  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • LASER_RANGE_FINDER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
int laser_range_finder_v2_set_write_firmware_pointer(LaserRangeFinderV2 *laser_range_finder_v2, uint32_t pointer)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • pointer – Type: uint32_t, Unit: 1 B, Range: [0 to 232 - 1]
Returns:
  • error_code – Type: int

Sets the firmware pointer for 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 laser_range_finder_v2_write_firmware(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t data[64], uint8_t *ret_status)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • data – Type: uint8_t[64], Range: [0 to 255]
Output Parameters:
  • ret_status – Type: uint8_t, Range: [0 to 255]
Returns:
  • error_code – Type: int

Writes 64 Bytes of firmware at the position as written by 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 laser_range_finder_v2_set_status_led_config(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t config)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • config – Type: uint8_t, Range: See constants, Default: 3
Returns:
  • error_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:

  • LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_OFF = 0
  • LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_ON = 1
  • LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
int laser_range_finder_v2_get_status_led_config(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t *ret_config)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:
  • error_code – Type: int

Returns the configuration as set by laser_range_finder_v2_set_status_led_config()

The following constants are available for this function:

For ret_config:

  • LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_OFF = 0
  • LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_ON = 1
  • LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • LASER_RANGE_FINDER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
int laser_range_finder_v2_get_chip_temperature(LaserRangeFinderV2 *laser_range_finder_v2, int16_t *ret_temperature)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_temperature – Type: int16_t, Unit: 1 °C, Range: [-215 to 215 - 1]
Returns:
  • error_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 laser_range_finder_v2_reset(LaserRangeFinderV2 *laser_range_finder_v2)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Returns:
  • error_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 laser_range_finder_v2_write_uid(LaserRangeFinderV2 *laser_range_finder_v2, uint32_t uid)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • uid – Type: uint32_t, Range: [0 to 232 - 1]
Returns:
  • error_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 laser_range_finder_v2_read_uid(LaserRangeFinderV2 *laser_range_finder_v2, uint32_t *ret_uid)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
Output Parameters:
  • ret_uid – Type: uint32_t, Range: [0 to 232 - 1]
Returns:
  • error_code – Type: int

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

int laser_range_finder_v2_get_identity(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: LaserRangeFinderV2 *
Output Parameters:
  • ret_uid – Type: char[8]
  • ret_connected_uid – Type: char[8]
  • ret_position – Type: char, Range: ['a' to 'h', 'i', '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:
  • error_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). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as 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 laser_range_finder_v2_register_callback(LaserRangeFinderV2 *laser_range_finder_v2, int16_t callback_id, void (*function)(void), void *user_data)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • 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 laser_range_finder_v2_set_distance_callback_configuration(LaserRangeFinderV2 *laser_range_finder_v2, uint32_t period, bool value_has_to_change, char option, int16_t min, int16_t max)
Parameters:
  • laser_range_finder_v2 – Type: 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:
  • error_code – Type: int

The period is the period with which the LASER_RANGE_FINDER_V2_CALLBACK_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 LASER_RANGE_FINDER_V2_CALLBACK_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:

  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OFF = 'x'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_SMALLER = '<'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_GREATER = '>'
int laser_range_finder_v2_get_distance_callback_configuration(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: 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:
  • error_code – Type: int

Returns the callback configuration as set by laser_range_finder_v2_set_distance_callback_configuration().

The following constants are available for this function:

For ret_option:

  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OFF = 'x'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_SMALLER = '<'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_GREATER = '>'
int laser_range_finder_v2_set_velocity_callback_configuration(LaserRangeFinderV2 *laser_range_finder_v2, uint32_t period, bool value_has_to_change, char option, int16_t min, int16_t max)
Parameters:
  • laser_range_finder_v2 – Type: 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:
  • error_code – Type: int

The period is the period with which the LASER_RANGE_FINDER_V2_CALLBACK_VELOCITY 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 LASER_RANGE_FINDER_V2_CALLBACK_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:

  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OFF = 'x'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_SMALLER = '<'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_GREATER = '>'
int laser_range_finder_v2_get_velocity_callback_configuration(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: 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:
  • error_code – Type: int

Returns the callback configuration as set by laser_range_finder_v2_set_velocity_callback_configuration().

The following constants are available for this function:

For ret_option:

  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OFF = 'x'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • LASER_RANGE_FINDER_V2_THRESHOLD_OPTION_SMALLER = '<'
  • 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 laser_range_finder_v2_register_callback() function:

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

laser_range_finder_v2_register_callback(&laser_range_finder_v2,
                                        LASER_RANGE_FINDER_V2_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.

LASER_RANGE_FINDER_V2_CALLBACK_DISTANCE
void callback(int16_t distance, void *user_data)
Callback Parameters:
  • 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 laser_range_finder_v2_set_distance_callback_configuration().

The parameter is the same as laser_range_finder_v2_get_distance().

LASER_RANGE_FINDER_V2_CALLBACK_VELOCITY
void callback(int16_t velocity, void *user_data)
Callback Parameters:
  • 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 laser_range_finder_v2_set_velocity_callback_configuration().

The parameter is the same as 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. They can be called without the corresponding IP Connection object being connected.

int laser_range_finder_v2_get_api_version(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t ret_api_version[3])
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
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:
  • error_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 laser_range_finder_v2_get_response_expected(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t function_id, bool *ret_response_expected)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • function_id – Type: uint8_t, Range: See constants
Output Parameters:
  • ret_response_expected – Type: bool
Returns:
  • error_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 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 send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

  • LASER_RANGE_FINDER_V2_FUNCTION_SET_DISTANCE_CALLBACK_CONFIGURATION = 2
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_VELOCITY_CALLBACK_CONFIGURATION = 6
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_ENABLE = 9
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_CONFIGURATION = 11
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_MOVING_AVERAGE = 13
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_OFFSET_CALIBRATION = 15
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_DISTANCE_LED_CONFIG = 17
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • LASER_RANGE_FINDER_V2_FUNCTION_RESET = 243
  • LASER_RANGE_FINDER_V2_FUNCTION_WRITE_UID = 248
int laser_range_finder_v2_set_response_expected(LaserRangeFinderV2 *laser_range_finder_v2, uint8_t function_id, bool response_expected)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • function_id – Type: uint8_t, Range: See constants
  • response_expected – Type: bool
Returns:
  • error_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.

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

The following constants are available for this function:

For function_id:

  • LASER_RANGE_FINDER_V2_FUNCTION_SET_DISTANCE_CALLBACK_CONFIGURATION = 2
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_VELOCITY_CALLBACK_CONFIGURATION = 6
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_ENABLE = 9
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_CONFIGURATION = 11
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_MOVING_AVERAGE = 13
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_OFFSET_CALIBRATION = 15
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_DISTANCE_LED_CONFIG = 17
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • LASER_RANGE_FINDER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • LASER_RANGE_FINDER_V2_FUNCTION_RESET = 243
  • LASER_RANGE_FINDER_V2_FUNCTION_WRITE_UID = 248
int laser_range_finder_v2_set_response_expected_all(LaserRangeFinderV2 *laser_range_finder_v2, bool response_expected)
Parameters:
  • laser_range_finder_v2 – Type: LaserRangeFinderV2 *
  • response_expected – Type: bool
Returns:
  • error_code – Type: int

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

Constants

LASER_RANGE_FINDER_V2_DEVICE_IDENTIFIER

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

The laser_range_finder_v2_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.

LASER_RANGE_FINDER_V2_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Laser Range Finder Bricklet 2.0.