Perl - Laser Range Finder Bricklet

This is the description of the Perl 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 Perl API bindings is part of their general description.

Examples

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

Simple

Download (example_simple.pl)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletLaserRangeFinder;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Laser Range Finder Bricklet

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $lrf = Tinkerforge::BrickletLaserRangeFinder->new(&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->enable_laser();
select(undef, undef, undef, 0.25);

# Get current distance
my $distance = $lrf->get_distance();
print "Distance: $distance cm\n";

print "Press key to exit\n";
<STDIN>;

$lrf->disable_laser(); # Turn laser off

$ipcon->disconnect();

Callback

Download (example_callback.pl)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletLaserRangeFinder;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Laser Range Finder Bricklet

# Callback subroutine for distance callback
sub cb_distance
{
    my ($distance) = @_;

    print "Distance: $distance cm\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $lrf = Tinkerforge::BrickletLaserRangeFinder->new(&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->enable_laser();
select(undef, undef, undef, 0.25);

# Register distance callback to subroutine cb_distance
$lrf->register_callback($lrf->CALLBACK_DISTANCE, '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->set_distance_callback_period(200);

print "Press key to exit\n";
<STDIN>;

$lrf->disable_laser(); # Turn laser off

$ipcon->disconnect();

Threshold

Download (example_threshold.pl)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletLaserRangeFinder;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Laser Range Finder Bricklet

# Callback subroutine for distance reached callback
sub cb_distance_reached
{
    my ($distance) = @_;

    print "Distance: $distance cm\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $lrf = Tinkerforge::BrickletLaserRangeFinder->new(&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->enable_laser();
select(undef, undef, undef, 0.25);

# Get threshold callbacks with a debounce time of 10 seconds (10000ms)
$lrf->set_debounce_period(10000);

# Register distance reached callback to subroutine cb_distance_reached
$lrf->register_callback($lrf->CALLBACK_DISTANCE_REACHED, 'cb_distance_reached');

# Configure threshold for distance "greater than 20 cm"
$lrf->set_distance_callback_threshold('>', 20, 0);

print "Press key to exit\n";
<STDIN>;

$lrf->disable_laser(); # Turn laser off

$ipcon->disconnect();

API

Generally, every subroutine of the Perl bindings can report an error as Tinkerforge::Error object via croak(). The object has a get_code() and a get_message() subroutine. There are different error code:

  • Error->ALREADY_CONNECTED = 11
  • Error->NOT_CONNECTED = 12
  • Error->CONNECT_FAILED = 13
  • Error->INVALID_FUNCTION_ID = 21
  • Error->TIMEOUT = 31
  • Error->INVALID_PARAMETER = 41
  • Error->FUNCTION_NOT_SUPPORTED = 42
  • Error->UNKNOWN_ERROR = 43
  • Error->STREAM_OUT_OF_SYNC = 51
  • Error->INVALID_UID = 61
  • Error->NON_ASCII_CHAR_IN_SECRET = 71
  • Error->WRONG_DEVICE_TYPE = 81
  • Error->DEVICE_REPLACED = 82
  • Error->WRONG_RESPONSE_LENGTH = 83

All functions listed below are thread-safe.

Basic Functions

BrickletLaserRangeFinder->new($uid, $ipcon)
Parameters:
  • $uid – Type: string
  • $ipcon – Type: IPConnection
Returns:
  • $laser_range_finder – Type: BrickletLaserRangeFinder

Creates an object with the unique device ID $uid:

$laser_range_finder = BrickletLaserRangeFinder->new("YOUR_DEVICE_UID", $ipcon);

This object can then be used after the IP Connection is connected.

BrickletLaserRangeFinder->get_distance()
Returns:
  • $distance – Type: int, Unit: 1 cm, Range: [0 to 4000]

Returns the measured distance.

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

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

BrickletLaserRangeFinder->get_velocity()
Returns:
  • $velocity – Type: int, Unit: 1 cm/s, Range: [-12800 to 12700]

Returns the measured velocity.

Sensor hardware version 1 (see get_sensor_hardware_version()) cannot measure distance and velocity at the same time. Therefore, the velocity mode has to be enabled using set_mode(). 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 set_configuration()) is configured. Also the laser has to be enabled, see enable_laser().

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

BrickletLaserRangeFinder->set_mode($mode)
Parameters:
  • $mode – Type: int, Range: See constants, Default: 0
Returns:
  • undef

Note

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

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
BrickletLaserRangeFinder->get_mode()
Returns:
  • $mode – Type: int, Range: See constants, Default: 0

Returns the mode as set by set_mode().

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
BrickletLaserRangeFinder->enable_laser()
Returns:
  • undef

Activates the laser of the LIDAR.

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

BrickletLaserRangeFinder->disable_laser()
Returns:
  • undef

Deactivates the laser of the LIDAR.

BrickletLaserRangeFinder->is_laser_enabled()
Returns:
  • $laser_enabled – Type: bool

Returns true if the laser is enabled, false otherwise.

BrickletLaserRangeFinder->set_configuration($acquisition_count, $enable_quick_termination, $threshold_value, $measurement_frequency)
Parameters:
  • $acquisition_count – Type: int, Range: [1 to 255], Default: 128
  • $enable_quick_termination – Type: bool, Default: 0
  • $threshold_value – Type: int, Range: [0 to 255], Default: 0
  • $measurement_frequency – Type: int, Unit: 1 Hz, Range: [0, 10 to 500], Default: 0
Returns:
  • undef

Note

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

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->get_configuration()
Return Array:
  • 0: $acquisition_count – Type: int, Range: [1 to 255], Default: 128
  • 1: $enable_quick_termination – Type: bool, Default: 0
  • 2: $threshold_value – Type: int, Range: [0 to 255], Default: 0
  • 3: $measurement_frequency – Type: int, Unit: 1 Hz, Range: [0, 10 to 500], Default: 0

Returns the configuration as set by set_configuration().

New in version 2.0.3 (Plugin).

Advanced Functions

BrickletLaserRangeFinder->set_moving_average($distance_average_length, $velocity_average_length)
Parameters:
  • $distance_average_length – Type: int, Range: [0 to 30], Default: 10
  • $velocity_average_length – Type: int, Range: [0 to 30], Default: 10
Returns:
  • undef

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->get_moving_average()
Return Array:
  • 0: $distance_average_length – Type: int, Range: [0 to 30], Default: 10
  • 1: $velocity_average_length – Type: int, Range: [0 to 30], Default: 10

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

BrickletLaserRangeFinder->get_sensor_hardware_version()
Returns:
  • $version – Type: int, 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->get_identity()
Return Array:
  • 0: $uid – Type: string, Length: up to 8
  • 1: $connected_uid – Type: string, Length: up to 8
  • 2: $position – Type: char, Range: ['a' to 'h', 'z']
  • 3: \@hardware_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, Range: [0 to 255]
  • 4: \@firmware_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, Range: [0 to 255]
  • 5: $device_identifier – 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). 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

BrickletLaserRangeFinder->register_callback($callback_id, $function)
Parameters:
  • $callback_id – Type: int
  • $function – Type: string
Returns:
  • undef

Registers the given $function name with the given $callback_id.

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

BrickletLaserRangeFinder->set_distance_callback_period($period)
Parameters:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Returns:
  • undef

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

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

BrickletLaserRangeFinder->get_distance_callback_period()
Returns:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by set_distance_callback_period().

BrickletLaserRangeFinder->set_velocity_callback_period($period)
Parameters:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Returns:
  • undef

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

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

BrickletLaserRangeFinder->get_velocity_callback_period()
Returns:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by set_velocity_callback_period().

BrickletLaserRangeFinder->set_distance_callback_threshold($option, $min, $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
Returns:
  • undef

Sets the thresholds for the CALLBACK_DISTANCE_REACHED 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->get_distance_callback_threshold()
Return Array:
  • 0: $option – Type: char, Range: See constants, Default: 'x'
  • 1: $min – Type: int, Unit: 1 cm, Range: [0 to 216 - 1], Default: 0
  • 2: $max – Type: int, Unit: 1 cm, Range: [0 to 216 - 1], Default: 0

Returns the threshold as set by set_distance_callback_threshold().

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->set_velocity_callback_threshold($option, $min, $max)
Parameters:
  • $option – Type: char, Range: See constants, Default: 'x'
  • $min – Type: int, Unit: 1 cm/s, Range: [-215 to 215 - 1], Default: 0
  • $max – Type: int, Unit: 1 cm/s, Range: [-215 to 215 - 1], Default: 0
Returns:
  • undef

Sets the thresholds for the CALLBACK_VELOCITY_REACHED 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->get_velocity_callback_threshold()
Return Array:
  • 0: $option – Type: char, Range: See constants, Default: 'x'
  • 1: $min – Type: int, Unit: 1 cm/s, Range: [-215 to 215 - 1], Default: 0
  • 2: $max – Type: int, Unit: 1 cm/s, Range: [-215 to 215 - 1], Default: 0

Returns the threshold as set by set_velocity_callback_threshold().

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->set_debounce_period($debounce)
Parameters:
  • $debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100
Returns:
  • undef

Sets the period with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

BrickletLaserRangeFinder->get_debounce_period()
Returns:
  • $debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by set_debounce_period().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the register_callback() function of the device object. The first parameter is the callback ID and the second parameter the callback function name:

sub my_callback
{
    print "@_[0]";
}

$laser_range_finder->register_callback(BrickletLaserRangeFinder->CALLBACK_EXAMPLE, 'my_callback')

The callback function will be called from an internal thread of the IP Connection. In contrast to many other programming languages, variables are not automatically shared between threads in Perl. If you want to share a global variable between a callback function and the rest for your program it has to be marked as :shared. See the documentation of the threads::shared Perl module for more details.

The available constants with inherent number and type of parameters 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.

BrickletLaserRangeFinder->CALLBACK_DISTANCE
Callback Parameters:
  • $distance – Type: int, Unit: 1 cm, Range: [0 to 4000]

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

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

BrickletLaserRangeFinder->CALLBACK_VELOCITY
Callback Parameters:
  • $velocity – Type: int, Unit: 1 cm/s, Range: [-12800 to 12700]

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

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

BrickletLaserRangeFinder->CALLBACK_DISTANCE_REACHED
Callback Parameters:
  • $distance – Type: int, Unit: 1 cm, Range: [0 to 4000]

This callback is triggered when the threshold as set by set_distance_callback_threshold() 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 set_debounce_period().

BrickletLaserRangeFinder->CALLBACK_VELOCITY_REACHED
Callback Parameters:
  • $velocity – Type: int, Unit: 1 cm/s, Range: [-12800 to 12700]

This callback is triggered when the threshold as set by set_velocity_callback_threshold() 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 set_debounce_period().

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.

BrickletLaserRangeFinder->get_api_version()
Return Array:
  • 0: \@api_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, 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.

BrickletLaserRangeFinder->get_response_expected($function_id)
Parameters:
  • $function_id – Type: int, Range: See constants
Returns:
  • $response_expected – Type: bool

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 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:

  • 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
BrickletLaserRangeFinder->set_response_expected($function_id, $response_expected)
Parameters:
  • $function_id – Type: int, Range: See constants
  • $response_expected – Type: bool
Returns:
  • undef

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

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

The following constants are available for this function:

For $function_id:

  • 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
BrickletLaserRangeFinder->set_response_expected_all($response_expected)
Parameters:
  • $response_expected – Type: bool
Returns:
  • undef

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

Constants

BrickletLaserRangeFinder->DEVICE_IDENTIFIER

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

The get_identity() function and the IPConnection->CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletLaserRangeFinder->DEVICE_DISPLAY_NAME

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