JavaScript - Laser Range Finder Bricklet – Tinkerforge

- Getting Started
  - Primer
  - Tutorials
  - FAQ
- Hardware
  - Bricks
  - Bricklets
  - Master Extensions
  - Power Supplies
  - Accessories
  - Timeline
- Software
  - Brick Daemon (brickd)
  - Brick Viewer (brickv)
  - API Bindings
  - Firmwares and Plugins
  - Device Identifier
  - Source Code and Bug Tracking
  - Programming Interface
- Starter Kits
  - Weather Station
  - Hardware Hacking
  - Server Room Monitoring
  - Blinkenlights
  - Internet of Things
  - Camera Slider
- Embedded Boards
  - Raspberry Pi
- Specifications
  - Technical Data
  - TCP/IP Protocol
  - Modbus Protocol
  - Wireshark Dissector

# JavaScript - Laser Range Finder Bricklet

Note

This Bricklet is currently in the prototype stage and the software/hardware as well as the documentation is in an incomplete state.

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

## Examples

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

### Simple (Node.js)

Download (ExampleSimple.js)

     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

    var Tinkerforge = require('tinkerforge');

    var HOST = 'localhost';
    var PORT = 4223;
    var UID = 'XYZ'; // Change to your UID

    var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
    var lrf = new Tinkerforge.BrickletLaserRangeFinder(UID, ipcon); // Create device object

    ipcon.connect(HOST, PORT,
        function(error) {
            console.log('Error: '+error);
        }
    ); // Connect to brickd

    // Don't use device before ipcon is connected
    ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
        function(connectReason) {
            // Turn laser on and wait 250ms for very first measurement to be ready
            lrf.enableLaser();
            setTimeout(function() {
                // Get current distance (unit is cm)
                lrf.getDistance(
                    function(distance) {
                        console.log('Distance: '+distance+' cm');
                    },
                    function(error) {
                        console.log('Error: '+error);
                    }
                )
            }, 250);
        }
    );

    console.log("Press any key to exit ...");
    process.stdin.on('data',
        function(data) {
            ipcon.disconnect();
            process.exit(0);
        }
    );

### Callback (Node.js)

Download (ExampleCallback.js)

     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44

    var Tinkerforge = require('tinkerforge');

    var HOST = 'localhost';
    var PORT = 4223;
    var UID = 'XYZ'; // Change to your UID

    var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
    var lrf = new Tinkerforge.BrickletLaserRangeFinder(UID, ipcon); // Create device object

    ipcon.connect(HOST, PORT,
        function(error) {
            console.log('Error: '+error);
        }
    ); // Connect to brickd
    // Don't use device before ipcon is connected

    ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
        function(connectReason) {
            // Turn laser on and wait 250ms for very first measurement to be ready
            lrf.enableLaser();
            setTimeout(function() {
                // Set Period for distance callback to 1s (1000ms)
                // Note: The distance callback is only called every second if the
                // distance has changed since the last call!
                lrf.setDistanceCallbackPeriod(1000);
            }, 250);
        }
    );

    // Register position callback
    lrf.on(Tinkerforge.BrickletLaserRangeFinder.CALLBACK_DISTANCE,
        // Callback function for distance callback (parameter has unit cm)
        function(distance) {
            console.log('Distance: '+distance+' cm');
        }
    );

    console.log("Press any key to exit ...");
    process.stdin.on('data',
        function(data) {
            ipcon.disconnect();
            process.exit(0);
        }
    );

### Threshold (Node.js)

Download (ExampleThreshold.js)

     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44

    var Tinkerforge = require('tinkerforge');

    var HOST = 'localhost';
    var PORT = 4223;
    var UID = 'XYZ'; // Change to your UID

    var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
    var lrf = new Tinkerforge.BrickletLaserRangeFinder(UID, ipcon); // Create device object

    ipcon.connect(HOST, PORT,
        function(error) {
            console.log('Error: '+error);
        }
    ); // Connect to brickd
    // Don't use device before ipcon is connected

    ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
        function(connectReason) {
            // Turn laser on and wait 250ms for very first measurement to be ready
            lrf.enableLaser();
            setTimeout(function() {
                // Get threshold callbacks with a debounce time of 10 seconds (10000ms)
                lrf.setDebouncePeriod(10000);
                // Configure threshold for "greater than 20 cm" (unit is cm)
                lrf.setDistanceCallbackThreshold('>', 200, 0);
            }, 250);
        }
    );

    // Register threshold reached callback to function cb_reached
    lrf.on(Tinkerforge.BrickletLaserRangeFinder.CALLBACK_DISTANCE_REACHED,
        // Callback for distance greater than 20 cm
        function(distance) {
            console.log('Distance: ' +distance + ' cm.');
        }
    );

    console.log("Press any key to exit ...");
    process.stdin.on('data',
        function(data) {
            ipcon.disconnect();
            process.exit(0);
        }
    );

### Simple (HTML)

Download (ExampleSimple.html), Test (ExampleSimple.html)

     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62

    <!DOCTYPE html>
    <html>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <head>
            <title>Tinkerforge | JavaScript Example</title>
        </head>
        <body>
            <div style="text-align:center;">
                <h1>Laser Range Finder Bricklet Simple Example</h1>
                <p>
                    <input value="localhost" id="host" type="text" size="20">:
                    <input value="4280" id="port" type="text" size="5">,
                    <input value="uid" id="uid" type="text" size="5">
                    <input value="Start Example" id="start" type="button" onclick="startExample();">
                </p>
                <p>
                    <textarea id="text" cols="80" rows="24" style="resize:none;"
                              >Press "Start Example" to begin ...</textarea>
                </p>
            <div>
            <script src="./Tinkerforge.js" type='text/javascript'></script>
            <script type='text/javascript'>
                var ipcon;
                var textArea = document.getElementById("text");
                function startExample() {
                    textArea.value = "";
                    var HOST = document.getElementById("host").value;
                    var PORT = parseInt(document.getElementById("port").value);
                    var UID = document.getElementById("uid").value;
                    if(ipcon !== undefined) {
                        ipcon.disconnect();
                    }
                    ipcon = new Tinkerforge.IPConnection(); // Create IP connection
                    var lrf = new Tinkerforge.BrickletLaserRangeFinder(UID, ipcon); // Create device object
                    ipcon.connect(HOST, PORT,
                        function(error) {
                            textArea.value += 'Error: '+error+ '\n';
                        }
                    ); // Connect to brickd
                    // Don't use device before ipcon is connected

                    ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
                        function(connectReason) {
                            // Turn laser on and wait 250ms for very first measurement to be ready
                            lrf.enableLaser();
                            setTimeout(function() {
                                // Get current distance (unit is cm)
                                lrf.getDistance(
                                    function(distance) {
                                        textArea.value += 'Distance: '+distance+' cm\n';
                                    },
                                    function(error) {
                                        textArea.value += 'Error: '+error+'\n';
                                    }
                                );
                            }, 250);
                        }
                    );
                }
            </script>
        </body>
    </html>

### Threshold (HTML)

Download (ExampleThreshold.html), Test (ExampleThreshold.html)

     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65

    <!DOCTYPE html>
    <html>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <head>
            <title>Tinkerforge | JavaScript Example</title>
        </head>
        <body>
            <div style="text-align:center;">
                <h1>Laser Range Finder Bricklet Threshold Example</h1>
                <p>
                    <input value="localhost" id="host" type="text" size="20">:
                    <input value="4280" id="port" type="text" size="5">,
                    <input value="uid" id="uid" type="text" size="5">
                    <input value="Start Example" id="start" type="button" onclick="startExample();">
                </p>
                <p>
                    <textarea id="text" cols="80" rows="24" style="resize:none;"
                              >Press "Start Example" to begin ...</textarea>
                </p>
            <div>
            <script src="./Tinkerforge.js" type='text/javascript'></script>
            <script type='text/javascript'>
                var ipcon;
                var textArea = document.getElementById("text");
                function startExample() {
                    textArea.value = "";
                    var HOST = document.getElementById("host").value;
                    var PORT = parseInt(document.getElementById("port").value);
                    var UID = document.getElementById("uid").value;
                    if(ipcon !== undefined) {
                        ipcon.disconnect();
                    }
                    ipcon = new Tinkerforge.IPConnection(); // Create IP connection
                    var lrf = new Tinkerforge.BrickletLaserRangeFinder(UID, ipcon); // Create device object
                    ipcon.connect(HOST, PORT,
                        function(error) {
                            textArea.value += 'Error: '+error+ '\n';
                        }
                    ); // Connect to brickd
                    // Don't use device before ipcon is connected

                    ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
                        function(connectReason) {
                            // Turn laser on and wait 250ms for very first measurement to be ready
                            lrf.enableLaser();
                            setTimeout(function() {
                                // Get threshold callbacks with a debounce time of 10 seconds (10000ms)
                                lrf.setDebouncePeriod(10000);
                                // Configure threshold for "greater than 20 cm"
                                lrf.setDistanceCallbackThreshold('>', 20, 0);
                            }, 250);
                        }
                    );
                    // Register threshold reached callback to function cb_reached
                    lrf.on(Tinkerforge.BrickletLaserRangeFinder.CALLBACK_DISTANCE_REACHED,
                        // Callback for distance greater than 20 cm
                        function(distance) {
                            textArea.value += 'Distance: ' +distance + ' cm\n';
                            textArea.scrollTop = textArea.scrollHeight;
                        }
                    );
                }
            </script>
        </body>
    </html>

### Callback (HTML)

Download (ExampleCallback.html), Test (ExampleCallback.html)

     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66

    <!DOCTYPE html>
    <html>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <head>
            <title>Tinkerforge | JavaScript Example</title>
        </head>
        <body>
            <div style="text-align:center;">
                <h1>Laser Range Finder Bricklet Callback Example</h1>
                <p>
                    <input value="localhost" id="host" type="text" size="20">:
                    <input value="4280" id="port" type="text" size="5">,
                    <input value="uid" id="uid" type="text" size="5">
                    <input value="Start Example" id="start" type="button" onclick="startExample();">
                </p>
                <p>
                    <textarea id="text" cols="80" rows="24" style="resize:none;"
                              >Press "Start Example" to begin ...</textarea>
                </p>
            <div>
            <script src="./Tinkerforge.js" type='text/javascript'></script>
            <script type='text/javascript'>
                var ipcon;
                var textArea = document.getElementById("text");
                function startExample() {
                    textArea.value = "";
                    var HOST = document.getElementById("host").value;
                    var PORT = parseInt(document.getElementById("port").value);
                    var UID = document.getElementById("uid").value;
                    if(ipcon !== undefined) {
                        ipcon.disconnect();
                    }
                    ipcon = new Tinkerforge.IPConnection(); // Create IP connection
                    var lrf = new Tinkerforge.BrickletLaserRangeFinder(UID, ipcon); // Create device object
                    ipcon.connect(HOST, PORT,
                        function(error) {
                            textArea.value += 'Error: '+error+ '\n';
                        }
                    ); // Connect to brickd
                    // Don't use device before ipcon is connected

                    ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
                        function(connectReason) {
                            // Turn laser on and wait 250ms for very first measurement to be ready
                            lrf.enableLaser();
                            setTimeout(function() {
                                // Set Period for distance callback to 1s (1000ms)
                                // Note: The distance callback is only called every second if the
                                // distance has changed since the last call!
                                lrf.setDistanceCallbackPeriod(1000);
                            }, 250);
                        }
                    );
                    // Register position callback
                    lrf.on(Tinkerforge.BrickletLaserRangeFinder.CALLBACK_DISTANCE,
                        // Callback function for distance callback (parameter has unit cm)
                        function(distance) {
                            textArea.value += 'Distance: '+distance+' cm';
                            textArea.value += '\n';
                            textArea.scrollTop = textArea.scrollHeight;
                        }
                    );
                }
            </script>
        </body>
    </html>

## API

Generally, every method of the JavaScript bindings can take two optional parameters, `returnCallback` and `errorCallback`. These are two user defined callback functions. The `returnCallback` is called with the return values as parameters, if the method returns something. The `errorCallback` is called with an error code in case of an error. The error code can be one of the following values:

- IPConnection.ERROR_ALREADY_CONNECTED = 11
- IPConnection.ERROR_NOT_CONNECTED = 12
- IPConnection.ERROR_CONNECT_FAILED = 13
- IPConnection.ERROR_INVALID_FUNCTION_ID = 21
- IPConnection.ERROR_TIMEOUT = 31
- IPConnection.ERROR_INVALID_PARAMETER = 41
- IPConnection.ERROR_FUNCTION_NOT_SUPPORTED = 42
- IPConnection.ERROR_UNKNOWN_ERROR = 43

The namespace for the JavaScript bindings is `Tinkerforge.*`.

### Basic Functions

new `BrickletLaserRangeFinder`(uid, ipcon)

  Parameters:

  - uid -- string
  - ipcon -- IPConnection

  Creates an object with the unique device ID `uid`:

      var laserRangeFinder = new BrickletLaserRangeFinder("YOUR_DEVICE_UID", ipcon);

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

`BrickletLaserRangeFinder.``getDistance`([returnCallback][, errorCallback])

  Callback:

  - distance -- int

  Returns the measured distance. The value has a range of 0 to 4000 and is given in cm.

  The Laser Range Finder Bricklet knows different modes. Distances are only measured in the distance measurement mode, see `setMode()`. Also the laser has to be enabled, see `enableLaser()`.

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

`BrickletLaserRangeFinder.``getVelocity`([returnCallback][, errorCallback])

  Callback:

  - velocity -- int

  Returns the measured velocity. The value has a range of 0 to 12700 and is given in 1/100 m/s.

  The Laser Range Finder Bricklet knows different modes. Velocity is only measured in the velocity measurement modes, see `setMode()`. Also the laser has to be enabled, see `enableLaser()`.

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

`BrickletLaserRangeFinder.``setMode`(mode[, returnCallback][, errorCallback])

  Parameters:

  - mode -- int

  Callback: | undefined

  The LIDAR 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 0-400 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 default mode is 0 (distance is measured).

  The following constants are available for this function:

  - 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.``getMode`([returnCallback][, errorCallback])

  Callback:

  - mode -- int

  Returns the mode as set by `setMode()`.

  The following constants are available for this function:

  - 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.``enableLaser`([returnCallback][, errorCallback])

  Callback: | undefined

  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.

`BrickletLaserRangeFinder.``disableLaser`([returnCallback][, errorCallback])

  Callback: | undefined

  Deactivates the laser of the LIDAR.

`BrickletLaserRangeFinder.``isLaserEnabled`([returnCallback][, errorCallback])

  Callback:

  - laserEnabled -- boolean

  Returns true if the laser is enabled, false otherwise.

### Advanced Functions

`BrickletLaserRangeFinder.``setMovingAverage`(distanceAverageLength, velocityAverageLength[, returnCallback][, errorCallback])

  Parameters:

  - distanceAverageLength -- int
  - velocityAverageLength -- int

  Callback: | undefined

  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.

  The range for the averaging is 0-30.

  The default value is 10.

`BrickletLaserRangeFinder.``getMovingAverage`([returnCallback][, errorCallback])

  Callback:

  - distanceAverageLength -- int
  - velocityAverageLength -- int

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

`BrickletLaserRangeFinder.``getAPIVersion`()

  Return type: | [int, int, int]

  Returns the version of the API definition (major, minor, revision) 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.``getResponseExpected`(functionId[, errorCallback])

  Parameters:

  - functionId -- int

  Return 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.

  See `setResponseExpected()` for the list of function ID constants available for this function.

`BrickletLaserRangeFinder.``setResponseExpected`(functionId, responseExpected[, errorCallback])

  Parameters:

  - functionId -- int
  - responseExpected -- 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 and callbacks it is always disabled.

  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 function ID constants are available for this function:

  - 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.``setResponseExpectedAll`(responseExpected)

  Parameters:

  - responseExpected -- boolean

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

`BrickletLaserRangeFinder.``getIdentity`([returnCallback][, errorCallback])

  Callback:

  - uid -- string
  - connectedUid -- string
  - position -- char
  - hardwareVersion -- [int, int, int]
  - firmwareVersion -- [int, int, int]
  - deviceIdentifier -- 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' or 'd'.

  The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

### Callback Configuration Functions

`BrickletLaserRangeFinder.``on`(id, callback)

  Parameters:

  - id -- int
  - callback -- function

  Registers a callback with ID id to the function callback. The available IDs with corresponding function signatures are listed below.

`BrickletLaserRangeFinder.``setDistanceCallbackPeriod`(period[, returnCallback][, errorCallback])

  Parameters:

  - period -- int

  Callback: | undefined

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

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

  The default value is 0.

`BrickletLaserRangeFinder.``getDistanceCallbackPeriod`([returnCallback][, errorCallback])

  Callback:

  - period -- int

  Returns the period as set by `setDistanceCallbackPeriod()`.

`BrickletLaserRangeFinder.``setVelocityCallbackPeriod`(period[, returnCallback][, errorCallback])

  Parameters:

  - period -- int

  Callback: | undefined

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

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

  The default value is 0.

`BrickletLaserRangeFinder.``getVelocityCallbackPeriod`([returnCallback][, errorCallback])

  Callback:

  - period -- int

  Returns the period as set by `setVelocityCallbackPeriod()`.

`BrickletLaserRangeFinder.``setDistanceCallbackThreshold`(option, min, max[, returnCallback][, errorCallback])

  Parameters:

  - option -- char
  - min -- int
  - max -- int

  Callback: | undefined

  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 default value is ('x', 0, 0).

  The following constants are available for this function:

  - BrickletLaserRangeFinder.THRESHOLD_OPTION_OFF = 'x'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_OUTSIDE = 'o'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_INSIDE = 'i'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_SMALLER = '<'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_GREATER = '>'

`BrickletLaserRangeFinder.``getDistanceCallbackThreshold`([returnCallback][, errorCallback])

  Callback:

  - option -- char
  - min -- int
  - max -- int

  Returns the threshold as set by `setDistanceCallbackThreshold()`.

  The following constants are available for this function:

  - BrickletLaserRangeFinder.THRESHOLD_OPTION_OFF = 'x'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_OUTSIDE = 'o'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_INSIDE = 'i'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_SMALLER = '<'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_GREATER = '>'

`BrickletLaserRangeFinder.``setVelocityCallbackThreshold`(option, min, max[, returnCallback][, errorCallback])

  Parameters:

  - option -- char
  - min -- int
  - max -- int

  Callback: | undefined

  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 default value is ('x', 0, 0).

  The following constants are available for this function:

  - BrickletLaserRangeFinder.THRESHOLD_OPTION_OFF = 'x'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_OUTSIDE = 'o'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_INSIDE = 'i'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_SMALLER = '<'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_GREATER = '>'

`BrickletLaserRangeFinder.``getVelocityCallbackThreshold`([returnCallback][, errorCallback])

  Callback:

  - option -- char
  - min -- int
  - max -- int

  Returns the threshold as set by `setVelocityCallbackThreshold()`.

  The following constants are available for this function:

  - BrickletLaserRangeFinder.THRESHOLD_OPTION_OFF = 'x'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_OUTSIDE = 'o'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_INSIDE = 'i'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_SMALLER = '<'
  - BrickletLaserRangeFinder.THRESHOLD_OPTION_GREATER = '>'

`BrickletLaserRangeFinder.``setDebouncePeriod`(debounce[, returnCallback][, errorCallback])

  Parameters:

  - debounce -- int

  Callback: | undefined

  Sets the period in ms with which the threshold callbacks

  - `CALLBACK_DISTANCE_REACHED`,
  - `CALLBACK_VELOCITY_REACHED`,

  are triggered, if the thresholds

  - `setDistanceCallbackThreshold()`,
  - `setVelocityCallbackThreshold()`,

  keep being reached.

  The default value is 100.

`BrickletLaserRangeFinder.``getDebouncePeriod`([returnCallback][, errorCallback])

  Callback:

  - debounce -- int

  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 the `on()` function of the device object. The first parameter is the callback ID and the second parameter the callback function:

    laserRangeFinder.on(BrickletLaserRangeFinder.CALLBACK_EXAMPLE,
        function (param) {
            console.log(param);
        }
    );

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`

  Parameters:

  - distance -- int

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

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

`BrickletLaserRangeFinder.``CALLBACK_VELOCITY`

  Parameters:

  - velocity -- int

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

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

`BrickletLaserRangeFinder.``CALLBACK_DISTANCE_REACHED`

  Parameters:

  - distance -- int

  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()`.

`BrickletLaserRangeFinder.``CALLBACK_VELOCITY_REACHED`

  Parameters:

  - velocity -- int

  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()`.

### Constants

`BrickletLaserRangeFinder.``DEVICE_IDENTIFIER`

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

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

The content of this page is licensed under Creative Commons Attribution 3.0 Unported License.