This is the description of the Visual Basic .NET API bindings for the Laser Range Finder Bricklet 2.0. General information and technical specifications for the Laser Range Finder Bricklet 2.0 are summarized in its hardware description.
An installation guide for the Visual Basic .NET API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
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 | Imports System
Imports System.Threading
Imports Tinkerforge
Module ExampleSimple
Const HOST As String = "localhost"
Const PORT As Integer = 4223
Const UID As String = "XYZ" ' Change XYZ to the UID of your Laser Range Finder Bricklet 2.0
Sub Main()
Dim ipcon As New IPConnection() ' Create IP connection
Dim lrf As New BrickletLaserRangeFinderV2(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.SetEnable(True)
Thread.Sleep(250)
' Get current distance
Dim distance As Short = lrf.GetDistance()
Console.WriteLine("Distance: " + distance.ToString() + " cm")
Console.WriteLine("Press key to exit")
Console.ReadLine()
' Turn laser off
lrf.SetEnable(False)
ipcon.Disconnect()
End Sub
End Module
|
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 | Imports System
Imports System.Threading
Imports Tinkerforge
Module ExampleCallback
Const HOST As String = "localhost"
Const PORT As Integer = 4223
Const UID As String = "XYZ" ' Change XYZ to the UID of your Laser Range Finder Bricklet 2.0
' Callback subroutine for distance callback
Sub DistanceCB(ByVal sender As BrickletLaserRangeFinderV2, ByVal distance As Short)
Console.WriteLine("Distance: " + distance.ToString() + " cm")
End Sub
Sub Main()
Dim ipcon As New IPConnection() ' Create IP connection
Dim lrf As New BrickletLaserRangeFinderV2(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.SetEnable(True)
Thread.Sleep(250)
' Register distance callback to subroutine DistanceCB
AddHandler lrf.DistanceCallback, AddressOf DistanceCB
' Set period for distance callback to 0.2s (200ms) without a threshold
lrf.SetDistanceCallbackConfiguration(200, False, "x"C, 0, 0)
Console.WriteLine("Press key to exit")
Console.ReadLine()
' Turn laser off
lrf.SetEnable(False)
ipcon.Disconnect()
End Sub
End Module
|
Download (ExampleThreshold.vb)
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 | Imports System
Imports System.Threading
Imports Tinkerforge
Module ExampleThreshold
Const HOST As String = "localhost"
Const PORT As Integer = 4223
Const UID As String = "XYZ" ' Change XYZ to the UID of your Laser Range Finder Bricklet 2.0
' Callback subroutine for distance callback
Sub DistanceCB(ByVal sender As BrickletLaserRangeFinderV2, ByVal distance As Short)
Console.WriteLine("Distance: " + distance.ToString() + " cm")
End Sub
Sub Main()
Dim ipcon As New IPConnection() ' Create IP connection
Dim lrf As New BrickletLaserRangeFinderV2(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.SetEnable(True)
Thread.Sleep(250)
' Register distance callback to subroutine DistanceCB
AddHandler lrf.DistanceCallback, AddressOf DistanceCB
' Configure threshold for distance "greater than 20 cm"
' with a debounce period of 1s (1000ms)
lrf.SetDistanceCallbackConfiguration(1000, False, ">"C, 20, 0)
Console.WriteLine("Press key to exit")
Console.ReadLine()
' Turn laser off
lrf.SetEnable(False)
ipcon.Disconnect()
End Sub
End Module
|
Since Visual Basic .NET does not support multiple return values directly, we
use the ByRef
keyword to return multiple values from a function.
All functions and procedures listed below are thread-safe.
BrickletLaserRangeFinderV2
(ByVal uid As String, ByVal ipcon As IPConnection)¶Creates an object with the unique device ID uid
:
Dim laserRangeFinderV2 As New BrickletLaserRangeFinderV2("YOUR_DEVICE_UID", ipcon)
This object can then be used after the IP Connection is connected.
BrickletLaserRangeFinderV2.
GetDistance
() As Short¶Returns: |
|
---|
Returns the measured distance.
The laser has to be enabled, see SetEnable()
.
If you want to get the value periodically, it is recommended to use the
DistanceCallback
callback. You can set the callback configuration
with SetDistanceCallbackConfiguration()
.
BrickletLaserRangeFinderV2.
GetVelocity
() As Short¶Returns: |
|
---|
Returns the measured velocity. The value has a range of -12800 to 12700 and is given in 1/100 m/s.
The velocity measurement only produces stables results if a fixed
measurement rate (see SetConfiguration()
) is configured. Also the laser
has to be enabled, see SetEnable()
.
If you want to get the value periodically, it is recommended to use the
VelocityCallback
callback. You can set the callback configuration
with SetVelocityCallbackConfiguration()
.
BrickletLaserRangeFinderV2.
SetEnable
(ByVal enable As Boolean)¶Parameters: |
|
---|
Enables the laser of the LIDAR if set to true.
We recommend that you wait 250ms after enabling the laser before
the first call of GetDistance()
to ensure stable measurements.
BrickletLaserRangeFinderV2.
GetEnable
() As Boolean¶Returns: |
|
---|
Returns the value as set by SetEnable()
.
BrickletLaserRangeFinderV2.
SetConfiguration
(ByVal acquisitionCount As Byte, ByVal enableQuickTermination As Boolean, ByVal thresholdValue As Byte, ByVal measurementFrequency As Integer)¶Parameters: |
|
---|
The Acquisition Count defines the number of times the Laser Range Finder Bricklet will integrate acquisitions to find a correlation record peak. With a higher count, the Bricklet can measure longer distances. With a lower count, the rate increases. The allowed values are 1-255.
If you set Enable Quick Termination to true, the distance measurement will be terminated early if a high peak was already detected. This means that a higher measurement rate can be achieved and long distances can be measured at the same time. However, the chance of false-positive distance measurements increases.
Normally the distance is calculated with a detection algorithm that uses peak value, signal strength and noise. You can however also define a fixed Threshold Value. Set this to a low value if you want to measure the distance to something that has very little reflection (e.g. glass) and set it to a high value if you want to measure the distance to something with a very high reflection (e.g. mirror). Set this to 0 to use the default algorithm. The other allowed values are 1-255.
Set the Measurement Frequency to force a fixed measurement rate. If set to 0, the Laser Range Finder Bricklet will use the optimal frequency according to the other configurations and the actual measured distance. Since the rate is not fixed in this case, the velocity measurement is not stable. For a stable velocity measurement you should set a fixed measurement frequency. The lower the frequency, the higher is the resolution of the calculated velocity. The allowed values are 10Hz-500Hz (and 0 to turn the fixed frequency off).
The default values for Acquisition Count, Enable Quick Termination, Threshold Value and Measurement Frequency are 128, false, 0 and 0.
BrickletLaserRangeFinderV2.
GetConfiguration
(ByRef acquisitionCount As Byte, ByRef enableQuickTermination As Boolean, ByRef thresholdValue As Byte, ByRef measurementFrequency As Integer)¶Output Parameters: |
|
---|
Returns the configuration as set by SetConfiguration()
.
BrickletLaserRangeFinderV2.
SetDistanceLEDConfig
(ByVal config As Byte)¶Parameters: |
|
---|
Configures the distance LED to be either turned off, turned on, blink in heartbeat mode or show the distance (brighter = object is nearer).
The following constants are available for this function:
For config:
BrickletLaserRangeFinderV2.
GetDistanceLEDConfig
() As Byte¶Returns: |
|
---|
Returns the LED configuration as set by SetDistanceLEDConfig()
The following constants are available for this function:
For config:
BrickletLaserRangeFinderV2.
SetMovingAverage
(ByVal distanceAverageLength As Byte, ByVal velocityAverageLength As Byte)¶Parameters: |
|
---|
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.
BrickletLaserRangeFinderV2.
GetMovingAverage
(ByRef distanceAverageLength As Byte, ByRef velocityAverageLength As Byte)¶Output Parameters: |
|
---|
Returns the length moving average as set by SetMovingAverage()
.
BrickletLaserRangeFinderV2.
SetOffsetCalibration
(ByVal offset As Short)¶Parameters: |
|
---|
The offset is added to the measured distance. It is saved in non-volatile memory, you only have to set it once.
The Bricklet comes with a per-sensor factory-calibrated offset value, you should not have to call this function.
If you want to re-calibrate the offset you first have to set it to 0. Calculate the offset by measuring the distance to a known distance and set it again.
BrickletLaserRangeFinderV2.
GetOffsetCalibration
() As Short¶Returns: |
|
---|
Returns the offset value as set by SetOffsetCalibration()
.
BrickletLaserRangeFinderV2.
GetSPITFPErrorCount
(ByRef errorCountAckChecksum As Long, ByRef errorCountMessageChecksum As Long, ByRef errorCountFrame As Long, ByRef errorCountOverflow As Long)¶Output Parameters: |
|
---|
Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.
BrickletLaserRangeFinderV2.
SetStatusLEDConfig
(ByVal config As Byte)¶Parameters: |
|
---|
Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.
You can also turn the LED permanently on/off or show a heartbeat.
If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.
The following constants are available for this function:
For config:
BrickletLaserRangeFinderV2.
GetStatusLEDConfig
() As Byte¶Returns: |
|
---|
Returns the configuration as set by SetStatusLEDConfig()
The following constants are available for this function:
For config:
BrickletLaserRangeFinderV2.
GetChipTemperature
() As Short¶Returns: |
|
---|
Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!
The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.
BrickletLaserRangeFinderV2.
Reset
()¶Calling this function will reset the Bricklet. All configurations will be lost.
After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!
BrickletLaserRangeFinderV2.
GetIdentity
(ByRef uid As String, ByRef connectedUid As String, ByRef position As Char, ByRef hardwareVersion() As Byte, ByRef firmwareVersion() As Byte, ByRef deviceIdentifier As Integer)¶Output Parameters: |
|
---|
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.
BrickletLaserRangeFinderV2.
SetDistanceCallbackConfiguration
(ByVal period As Long, ByVal valueHasToChange As Boolean, ByVal option As Char, ByVal min As Short, ByVal max As Short)¶Parameters: |
|
---|
The period is the period with which the DistanceCallback
callback is triggered
periodically. A value of 0 turns the callback off.
If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.
If it is set to false, the callback is continuously triggered with the period, independent of the value.
It is furthermore possible to constrain the callback with thresholds.
The option-parameter together with min/max sets a threshold for the DistanceCallback
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Threshold is turned off |
'o' | Threshold is triggered when the value is outside the min and max values |
'i' | Threshold is triggered when the value is inside or equal to the min and max values |
'<' | Threshold is triggered when the value is smaller than the min value (max is ignored) |
'>' | Threshold is triggered when the value is greater than the min value (max is ignored) |
If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.
The following constants are available for this function:
For option:
BrickletLaserRangeFinderV2.
GetDistanceCallbackConfiguration
(ByRef period As Long, ByRef valueHasToChange As Boolean, ByRef option As Char, ByRef min As Short, ByRef max As Short)¶Output Parameters: |
|
---|
Returns the callback configuration as set by SetDistanceCallbackConfiguration()
.
The following constants are available for this function:
For option:
BrickletLaserRangeFinderV2.
SetVelocityCallbackConfiguration
(ByVal period As Long, ByVal valueHasToChange As Boolean, ByVal option As Char, ByVal min As Short, ByVal max As Short)¶Parameters: |
|
---|
The period is the period with which the VelocityCallback
callback is triggered
periodically. A value of 0 turns the callback off.
If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.
If it is set to false, the callback is continuously triggered with the period, independent of the value.
It is furthermore possible to constrain the callback with thresholds.
The option-parameter together with min/max sets a threshold for the VelocityCallback
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Threshold is turned off |
'o' | Threshold is triggered when the value is outside the min and max values |
'i' | Threshold is triggered when the value is inside or equal to the min and max values |
'<' | Threshold is triggered when the value is smaller than the min value (max is ignored) |
'>' | Threshold is triggered when the value is greater than the min value (max is ignored) |
If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.
The following constants are available for this function:
For option:
BrickletLaserRangeFinderV2.
GetVelocityCallbackConfiguration
(ByRef period As Long, ByRef valueHasToChange As Boolean, ByRef option As Char, ByRef min As Short, ByRef max As Short)¶Output Parameters: |
|
---|
Returns the callback configuration as set by SetVelocityCallbackConfiguration()
.
The following constants are available for this function:
For option:
Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a procedure to an callback property of the device object:
Sub MyCallback(ByVal sender As BrickletLaserRangeFinderV2, ByVal value As Short) Console.WriteLine("Value: {0}", value) End Sub AddHandler laserRangeFinderV2.ExampleCallback, AddressOf MyCallback
The available callback property and their 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.
BrickletLaserRangeFinderV2.
DistanceCallback
(ByVal sender As BrickletLaserRangeFinderV2, ByVal distance As Short)¶Callback Parameters: |
|
---|
This callback is triggered periodically according to the configuration set by
SetDistanceCallbackConfiguration()
.
The parameter is the same as GetDistance()
.
BrickletLaserRangeFinderV2.
VelocityCallback
(ByVal sender As BrickletLaserRangeFinderV2, ByVal velocity As Short)¶Callback Parameters: |
|
---|
This callback is triggered periodically according to the configuration set by
SetVelocityCallbackConfiguration()
.
The parameter is the same as GetVelocity()
.
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.
BrickletLaserRangeFinderV2.
GetAPIVersion
() As Byte()¶Output Parameters: |
|
---|
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.
BrickletLaserRangeFinderV2.
GetResponseExpected
(ByVal functionId As Byte) As Boolean¶Parameters: |
|
---|---|
Returns: |
|
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 sent and errors are silently ignored, because they cannot be detected.
The following constants are available for this function:
For functionId:
BrickletLaserRangeFinderV2.
SetResponseExpected
(ByVal functionId As Byte, ByVal responseExpected As Boolean)¶Parameters: |
|
---|
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 functionId:
BrickletLaserRangeFinderV2.
SetResponseExpectedAll
(ByVal responseExpected As Boolean)¶Parameters: |
|
---|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.
BrickletLaserRangeFinderV2.
SetBootloaderMode
(ByVal mode As Byte) As Byte¶Parameters: |
|
---|---|
Returns: |
|
Sets the bootloader mode and returns the status after the requested mode change was instigated.
You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
The following constants are available for this function:
For mode:
For status:
BrickletLaserRangeFinderV2.
GetBootloaderMode
() As Byte¶Returns: |
|
---|
Returns the current bootloader mode, see SetBootloaderMode()
.
The following constants are available for this function:
For mode:
BrickletLaserRangeFinderV2.
SetWriteFirmwarePointer
(ByVal pointer As Long)¶Parameters: |
|
---|
Sets the firmware pointer for WriteFirmware()
. The pointer has
to be increased by chunks of size 64. The data is written to flash
every 4 chunks (which equals to one page of size 256).
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
BrickletLaserRangeFinderV2.
WriteFirmware
(ByVal data() As Byte) As Byte¶Parameters: |
|
---|---|
Returns: |
|
Writes 64 Bytes of firmware at the position as written by
SetWriteFirmwarePointer()
before. The firmware is written
to flash every 4 chunks.
You can only write firmware in bootloader mode.
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
BrickletLaserRangeFinderV2.
WriteUID
(ByVal uid As Long)¶Parameters: |
|
---|
Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.
We recommend that you use Brick Viewer to change the UID.
BrickletLaserRangeFinderV2.
ReadUID
() As Long¶Returns: |
|
---|
Returns the current UID as an integer. Encode as Base58 to get the usual string version.
BrickletLaserRangeFinderV2.
DEVICE_IDENTIFIER
¶This constant is used to identify a Laser Range Finder Bricklet 2.0.
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.
BrickletLaserRangeFinderV2.
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Laser Range Finder Bricklet 2.0.