MATLAB/Octave - Laser Range Finder Bricklet

This is the description of the MATLAB/Octave API bindings for the Laser Range Finder Bricklet. General information and technical specifications for the Laser Range Finder Bricklet are summarized in its hardware description.

An installation guide for the MATLAB/Octave API bindings is part of their general description.

Examples

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

Simple (MATLAB)

Download (matlab_example_simple.m)

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function matlab_example_simple()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletLaserRangeFinder;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your Laser Range Finder Bricklet

    ipcon = IPConnection(); % Create IP connection
    lrf = handle(BrickletLaserRangeFinder(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Turn laser on and wait 250ms for very first measurement to be ready
    lrf.enableLaser();
    pause(0.25);

    % Get current distance
    distance = lrf.getDistance();
    fprintf('Distance: %i cm\n', distance);

    input('Press key to exit\n', 's');
    lrf.disableLaser(); % Turn laser off
    ipcon.disconnect();
end

Callback (MATLAB)

Download (matlab_example_callback.m)

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function matlab_example_callback()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletLaserRangeFinder;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your Laser Range Finder Bricklet

    ipcon = IPConnection(); % Create IP connection
    lrf = handle(BrickletLaserRangeFinder(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Turn laser on and wait 250ms for very first measurement to be ready
    lrf.enableLaser();
    pause(0.25);

    % Register distance callback to function cb_distance
    set(lrf, 'DistanceCallback', @(h, e) cb_distance(e));

    % Set period for distance callback to 0.2s (200ms)
    % Note: The distance callback is only called every 0.2 seconds
    %       if the distance has changed since the last call!
    lrf.setDistanceCallbackPeriod(200);

    input('Press key to exit\n', 's');
    lrf.disableLaser(); % Turn laser off
    ipcon.disconnect();
end

% Callback function for distance callback
function cb_distance(e)
    fprintf('Distance: %i cm\n', e.distance);
end

Threshold (MATLAB)

Download (matlab_example_threshold.m)

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function matlab_example_threshold()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletLaserRangeFinder;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your Laser Range Finder Bricklet

    ipcon = IPConnection(); % Create IP connection
    lrf = handle(BrickletLaserRangeFinder(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Turn laser on and wait 250ms for very first measurement to be ready
    lrf.enableLaser();
    pause(0.25);

    % Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    lrf.setDebouncePeriod(10000);

    % Register distance reached callback to function cb_distance_reached
    set(lrf, 'DistanceReachedCallback', @(h, e) cb_distance_reached(e));

    % Configure threshold for distance "greater than 20 cm"
    lrf.setDistanceCallbackThreshold('>', 20, 0);

    input('Press key to exit\n', 's');
    lrf.disableLaser(); % Turn laser off
    ipcon.disconnect();
end

% Callback function for distance reached callback
function cb_distance_reached(e)
    fprintf('Distance: %i cm\n', e.distance);
end

Simple (Octave)

Download (octave_example_simple.m)

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function octave_example_simple()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Laser Range Finder Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    lrf = javaObject("com.tinkerforge.BrickletLaserRangeFinder", UID, ipcon); % Create device object

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

    % Turn laser on and wait 250ms for very first measurement to be ready
    lrf.enableLaser();
    pause(0.25);

    % Get current distance
    distance = lrf.getDistance();
    fprintf("Distance: %d cm\n", distance);

    input("Press key to exit\n", "s");
    lrf.disableLaser(); % Turn laser off
    ipcon.disconnect();
end

Callback (Octave)

Download (octave_example_callback.m)

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function octave_example_callback()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Laser Range Finder Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    lrf = javaObject("com.tinkerforge.BrickletLaserRangeFinder", UID, ipcon); % Create device object

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

    % Turn laser on and wait 250ms for very first measurement to be ready
    lrf.enableLaser();
    pause(0.25);

    % Register distance callback to function cb_distance
    lrf.addDistanceCallback(@cb_distance);

    % Set period for distance callback to 0.2s (200ms)
    % Note: The distance callback is only called every 0.2 seconds
    %       if the distance has changed since the last call!
    lrf.setDistanceCallbackPeriod(200);

    input("Press key to exit\n", "s");
    lrf.disableLaser(); % Turn laser off
    ipcon.disconnect();
end

% Callback function for distance callback
function cb_distance(e)
    fprintf("Distance: %d cm\n", e.distance);
end

Threshold (Octave)

Download (octave_example_threshold.m)

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function octave_example_threshold()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Laser Range Finder Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    lrf = javaObject("com.tinkerforge.BrickletLaserRangeFinder", UID, ipcon); % Create device object

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

    % Turn laser on and wait 250ms for very first measurement to be ready
    lrf.enableLaser();
    pause(0.25);

    % Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    lrf.setDebouncePeriod(10000);

    % Register distance reached callback to function cb_distance_reached
    lrf.addDistanceReachedCallback(@cb_distance_reached);

    % Configure threshold for distance "greater than 20 cm"
    lrf.setDistanceCallbackThreshold(">", 20, 0);

    input("Press key to exit\n", "s");
    lrf.disableLaser(); % Turn laser off
    ipcon.disconnect();
end

% Callback function for distance reached callback
function cb_distance_reached(e)
    fprintf("Distance: %d cm\n", e.distance);
end

API

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

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

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

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

All methods listed below are thread-safe.

Basic Functions

class BrickletLaserRangeFinder(String uid, IPConnection ipcon)
Parameters:
  • uid – Type: String
  • ipcon – Type: IPConnection
Returns:
  • laserRangeFinder – Type: BrickletLaserRangeFinder

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletLaserRangeFinder;

laserRangeFinder = BrickletLaserRangeFinder('YOUR_DEVICE_UID', ipcon);

In Octave:

laserRangeFinder = java_new("com.tinkerforge.BrickletLaserRangeFinder", "YOUR_DEVICE_UID", ipcon);

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

int BrickletLaserRangeFinder.getDistance()
Returns:
  • distance – Type: int, Unit: 1 cm, Range: [0 to 4000]

Returns the measured distance.

Sensor hardware version 1 (see getSensorHardwareVersion()) cannot measure distance and velocity at the same time. Therefore, the distance mode has to be enabled using setMode(). Sensor hardware version 3 can measure distance and velocity at the same time. Also the laser has to be enabled, see enableLaser().

If you want to get the distance periodically, it is recommended to use the DistanceCallback callback and set the period with setDistanceCallbackPeriod().

short BrickletLaserRangeFinder.getVelocity()
Returns:
  • velocity – Type: short, Unit: 1 cm/s, Range: [-12800 to 12700]

Returns the measured velocity.

Sensor hardware version 1 (see getSensorHardwareVersion()) cannot measure distance and velocity at the same time. Therefore, the velocity mode has to be enabled using setMode(). Sensor hardware version 3 can measure distance and velocity at the same time, but the velocity measurement only produces stables results if a fixed measurement rate (see setConfiguration()) is configured. Also the laser has to be enabled, see enableLaser().

If you want to get the velocity periodically, it is recommended to use the VelocityCallback callback and set the period with setVelocityCallbackPeriod().

void BrickletLaserRangeFinder.setMode(short mode)
Parameters:
  • mode – Type: short, Range: See constants, Default: 0

Note

This function is only available if you have a LIDAR-Lite sensor with hardware version 1. Use setConfiguration() for hardware version 3. You can check the sensor hardware version using getSensorHardwareVersion().

The LIDAR-Lite sensor (hardware version 1) has five different modes. One mode is for distance measurements and four modes are for velocity measurements with different ranges.

The following modes are available:

  • 0: Distance is measured with resolution 1.0 cm and range 0-4000 cm
  • 1: Velocity is measured with resolution 0.1 m/s and range is 0-12.7 m/s
  • 2: Velocity is measured with resolution 0.25 m/s and range is 0-31.75 m/s
  • 3: Velocity is measured with resolution 0.5 m/s and range is 0-63.5 m/s
  • 4: Velocity is measured with resolution 1.0 m/s and range is 0-127 m/s

The following constants are available for this function:

For mode:

  • BrickletLaserRangeFinder.MODE_DISTANCE = 0
  • BrickletLaserRangeFinder.MODE_VELOCITY_MAX_13MS = 1
  • BrickletLaserRangeFinder.MODE_VELOCITY_MAX_32MS = 2
  • BrickletLaserRangeFinder.MODE_VELOCITY_MAX_64MS = 3
  • BrickletLaserRangeFinder.MODE_VELOCITY_MAX_127MS = 4
short BrickletLaserRangeFinder.getMode()
Returns:
  • mode – Type: short, Range: See constants, Default: 0

Returns the mode as set by setMode().

The following constants are available for this function:

For mode:

  • BrickletLaserRangeFinder.MODE_DISTANCE = 0
  • BrickletLaserRangeFinder.MODE_VELOCITY_MAX_13MS = 1
  • BrickletLaserRangeFinder.MODE_VELOCITY_MAX_32MS = 2
  • BrickletLaserRangeFinder.MODE_VELOCITY_MAX_64MS = 3
  • BrickletLaserRangeFinder.MODE_VELOCITY_MAX_127MS = 4
void BrickletLaserRangeFinder.enableLaser()

Activates the laser of the LIDAR.

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

void BrickletLaserRangeFinder.disableLaser()

Deactivates the laser of the LIDAR.

boolean BrickletLaserRangeFinder.isLaserEnabled()
Returns:
  • laserEnabled – Type: boolean

Returns true if the laser is enabled, false otherwise.

void BrickletLaserRangeFinder.setConfiguration(short acquisitionCount, boolean enableQuickTermination, short thresholdValue, int measurementFrequency)
Parameters:
  • acquisitionCount – Type: short, Range: [1 to 255], Default: 128
  • enableQuickTermination – Type: boolean, Default: false
  • thresholdValue – Type: short, Range: [0 to 255], Default: 0
  • measurementFrequency – Type: int, Unit: 1 Hz, Range: [0, 10 to 500], Default: 0

Note

This function is only available if you have a LIDAR-Lite sensor with hardware version 3. Use setMode() for hardware version 1. You can check the sensor hardware version using getSensorHardwareVersion().

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).

New in version 2.0.3 (Plugin).

BrickletLaserRangeFinder.Configuration BrickletLaserRangeFinder.getConfiguration()
Return Object:
  • acquisitionCount – Type: short, Range: [1 to 255], Default: 128
  • enableQuickTermination – Type: boolean, Default: false
  • thresholdValue – Type: short, Range: [0 to 255], Default: 0
  • measurementFrequency – Type: int, Unit: 1 Hz, Range: [0, 10 to 500], Default: 0

Returns the configuration as set by setConfiguration().

New in version 2.0.3 (Plugin).

Advanced Functions

void BrickletLaserRangeFinder.setMovingAverage(short distanceAverageLength, short velocityAverageLength)
Parameters:
  • distanceAverageLength – Type: short, Range: [0 to 30], Default: 10
  • velocityAverageLength – Type: short, Range: [0 to 30], Default: 10

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.

BrickletLaserRangeFinder.MovingAverage BrickletLaserRangeFinder.getMovingAverage()
Return Object:
  • distanceAverageLength – Type: short, Range: [0 to 30], Default: 10
  • velocityAverageLength – Type: short, Range: [0 to 30], Default: 10

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

short BrickletLaserRangeFinder.getSensorHardwareVersion()
Returns:
  • version – Type: short, Range: See constants

Returns the LIDAR-Lite hardware version.

The following constants are available for this function:

For version:

  • BrickletLaserRangeFinder.VERSION_1 = 1
  • BrickletLaserRangeFinder.VERSION_3 = 3

New in version 2.0.3 (Plugin).

BrickletLaserRangeFinder.Identity BrickletLaserRangeFinder.getIdentity()
Return Object:
  • uid – Type: String, Length: up to 8
  • connectedUid – Type: String, Length: up to 8
  • position – Type: char, Range: ['a' to 'i', 'z']
  • hardwareVersion – Type: short[], Length: 3
    • 1: major – Type: short, Range: [0 to 255]
    • 2: minor – Type: short, Range: [0 to 255]
    • 3: revision – Type: short, Range: [0 to 255]
  • firmwareVersion – Type: short[], Length: 3
    • 1: major – Type: short, Range: [0 to 255]
    • 2: minor – Type: short, Range: [0 to 255]
    • 3: revision – Type: short, Range: [0 to 255]
  • deviceIdentifier – Type: int, Range: [0 to 216 - 1]

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 BrickletLaserRangeFinder.setDistanceCallbackPeriod(long period)
Parameters:
  • period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

The DistanceCallback callback is only triggered if the distance value has changed since the last triggering.

long BrickletLaserRangeFinder.getDistanceCallbackPeriod()
Returns:
  • period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by setDistanceCallbackPeriod().

void BrickletLaserRangeFinder.setVelocityCallbackPeriod(long period)
Parameters:
  • period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

The VelocityCallback callback is only triggered if the velocity value has changed since the last triggering.

long BrickletLaserRangeFinder.getVelocityCallbackPeriod()
Returns:
  • period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by setVelocityCallbackPeriod().

void BrickletLaserRangeFinder.setDistanceCallbackThreshold(char option, int min, int max)
Parameters:
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: int, Unit: 1 cm, Range: [0 to 216 - 1], Default: 0
  • max – Type: int, Unit: 1 cm, Range: [0 to 216 - 1], Default: 0

Sets the thresholds for the DistanceReachedCallback callback.

The following options are possible:

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

The following constants are available for this function:

For option:

  • BrickletLaserRangeFinder.THRESHOLD_OPTION_OFF = 'x'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_GREATER = '>'
BrickletLaserRangeFinder.DistanceCallbackThreshold BrickletLaserRangeFinder.getDistanceCallbackThreshold()
Return Object:
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: int, Unit: 1 cm, Range: [0 to 216 - 1], Default: 0
  • max – Type: int, Unit: 1 cm, Range: [0 to 216 - 1], Default: 0

Returns the threshold as set by setDistanceCallbackThreshold().

The following constants are available for this function:

For option:

  • BrickletLaserRangeFinder.THRESHOLD_OPTION_OFF = 'x'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_GREATER = '>'
void BrickletLaserRangeFinder.setVelocityCallbackThreshold(char option, short min, short max)
Parameters:
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: short, Unit: 1 cm/s, Range: [-215 to 215 - 1], Default: 0
  • max – Type: short, Unit: 1 cm/s, Range: [-215 to 215 - 1], Default: 0

Sets the thresholds for the VelocityReachedCallback callback.

The following options are possible:

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

The following constants are available for this function:

For option:

  • BrickletLaserRangeFinder.THRESHOLD_OPTION_OFF = 'x'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_GREATER = '>'
BrickletLaserRangeFinder.VelocityCallbackThreshold BrickletLaserRangeFinder.getVelocityCallbackThreshold()
Return Object:
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: short, Unit: 1 cm/s, Range: [-215 to 215 - 1], Default: 0
  • max – Type: short, Unit: 1 cm/s, Range: [-215 to 215 - 1], Default: 0

Returns the threshold as set by setVelocityCallbackThreshold().

The following constants are available for this function:

For option:

  • BrickletLaserRangeFinder.THRESHOLD_OPTION_OFF = 'x'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletLaserRangeFinder.THRESHOLD_OPTION_GREATER = '>'
void BrickletLaserRangeFinder.setDebouncePeriod(long debounce)
Parameters:
  • debounce – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Sets the period with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

long BrickletLaserRangeFinder.getDebouncePeriod()
Returns:
  • debounce – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by setDebouncePeriod().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with "set" function of MATLAB. The parameters consist of the IP Connection object, the callback name and the callback function. For example, it looks like this in MATLAB:

function my_callback(e)
    fprintf('Parameter: %s\n', e.param);
end

set(device, 'ExampleCallback', @(h, e) my_callback(e));

Due to a difference in the Octave Java support the "set" function cannot be used in Octave. The registration is done with "add*Callback" functions of the device object. It looks like this in Octave:

function my_callback(e)
    fprintf("Parameter: %s\n", e.param);
end

device.addExampleCallback(@my_callback);

It is possible to add several callbacks and to remove them with the corresponding "remove*Callback" function.

The parameters of the callback are passed to the callback function as fields of the structure e, which is derived from the java.util.EventObject class. The available callback names with corresponding structure fields 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.

callback BrickletLaserRangeFinder.DistanceCallback
Event Object:
  • distance – Type: int, Unit: 1 cm, Range: [0 to 4000]

This callback is triggered periodically with the period that is set by setDistanceCallbackPeriod(). The parameter is the distance value of the sensor.

The DistanceCallback callback is only triggered if the distance value has changed since the last triggering.

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addDistanceCallback() function. An added callback function can be removed with the removeDistanceCallback() function.

callback BrickletLaserRangeFinder.VelocityCallback
Event Object:
  • velocity – Type: short, Unit: 1 cm/s, Range: [-12800 to 12700]

This callback is triggered periodically with the period that is set by setVelocityCallbackPeriod(). The parameter is the velocity value of the sensor.

The VelocityCallback callback is only triggered if the velocity has changed since the last triggering.

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addVelocityCallback() function. An added callback function can be removed with the removeVelocityCallback() function.

callback BrickletLaserRangeFinder.DistanceReachedCallback
Event Object:
  • distance – Type: int, Unit: 1 cm, Range: [0 to 4000]

This callback is triggered when the threshold as set by setDistanceCallbackThreshold() is reached. The parameter is the distance value of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by setDebouncePeriod().

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addDistanceReachedCallback() function. An added callback function can be removed with the removeDistanceReachedCallback() function.

callback BrickletLaserRangeFinder.VelocityReachedCallback
Event Object:
  • velocity – Type: short, Unit: 1 cm/s, Range: [-12800 to 12700]

This callback is triggered when the threshold as set by setVelocityCallbackThreshold() is reached. The parameter is the velocity value of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by setDebouncePeriod().

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addVelocityReachedCallback() function. An added callback function can be removed with the removeVelocityReachedCallback() function.

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.

short[] BrickletLaserRangeFinder.getAPIVersion()
Return Object:
  • apiVersion – Type: short[], Length: 3
    • 1: major – Type: short, Range: [0 to 255]
    • 2: minor – Type: short, Range: [0 to 255]
    • 3: revision – Type: short, Range: [0 to 255]

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.

boolean BrickletLaserRangeFinder.getResponseExpected(short functionId)
Parameters:
  • functionId – Type: short, Range: See constants
Returns:
  • responseExpected – Type: boolean

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 setResponseExpected(). For setter functions it is disabled by default and can be enabled.

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

The following constants are available for this function:

For functionId:

  • BrickletLaserRangeFinder.FUNCTION_SET_DISTANCE_CALLBACK_PERIOD = 3
  • BrickletLaserRangeFinder.FUNCTION_SET_VELOCITY_CALLBACK_PERIOD = 5
  • BrickletLaserRangeFinder.FUNCTION_SET_DISTANCE_CALLBACK_THRESHOLD = 7
  • BrickletLaserRangeFinder.FUNCTION_SET_VELOCITY_CALLBACK_THRESHOLD = 9
  • BrickletLaserRangeFinder.FUNCTION_SET_DEBOUNCE_PERIOD = 11
  • BrickletLaserRangeFinder.FUNCTION_SET_MOVING_AVERAGE = 13
  • BrickletLaserRangeFinder.FUNCTION_SET_MODE = 15
  • BrickletLaserRangeFinder.FUNCTION_ENABLE_LASER = 17
  • BrickletLaserRangeFinder.FUNCTION_DISABLE_LASER = 18
  • BrickletLaserRangeFinder.FUNCTION_SET_CONFIGURATION = 25
void BrickletLaserRangeFinder.setResponseExpected(short functionId, boolean responseExpected)
Parameters:
  • functionId – Type: short, Range: See constants
  • responseExpected – Type: boolean

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 functionId:

  • BrickletLaserRangeFinder.FUNCTION_SET_DISTANCE_CALLBACK_PERIOD = 3
  • BrickletLaserRangeFinder.FUNCTION_SET_VELOCITY_CALLBACK_PERIOD = 5
  • BrickletLaserRangeFinder.FUNCTION_SET_DISTANCE_CALLBACK_THRESHOLD = 7
  • BrickletLaserRangeFinder.FUNCTION_SET_VELOCITY_CALLBACK_THRESHOLD = 9
  • BrickletLaserRangeFinder.FUNCTION_SET_DEBOUNCE_PERIOD = 11
  • BrickletLaserRangeFinder.FUNCTION_SET_MOVING_AVERAGE = 13
  • BrickletLaserRangeFinder.FUNCTION_SET_MODE = 15
  • BrickletLaserRangeFinder.FUNCTION_ENABLE_LASER = 17
  • BrickletLaserRangeFinder.FUNCTION_DISABLE_LASER = 18
  • BrickletLaserRangeFinder.FUNCTION_SET_CONFIGURATION = 25
void BrickletLaserRangeFinder.setResponseExpectedAll(boolean responseExpected)
Parameters:
  • responseExpected – Type: boolean

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

Constants

int BrickletLaserRangeFinder.DEVICE_IDENTIFIER

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

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

String BrickletLaserRangeFinder.DEVICE_DISPLAY_NAME

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