This is the description of the Mathematica 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 Mathematica 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 | Needs["NETLink`"]
LoadNETAssembly["Tinkerforge",NotebookDirectory[]<>"../../.."]
host="localhost"
port=4223
uid="XYZ"(*Change XYZ to the UID of your Laser Range Finder Bricklet*)
(*Create IPConnection and device object*)
ipcon=NETNew["Tinkerforge.IPConnection"]
lrf=NETNew["Tinkerforge.BrickletLaserRangeFinder",uid,ipcon]
ipcon@Connect[host,port]
(*Turn laser on and wait 250ms for very first measurement to be ready*)
lrf@EnableLaser[]
Pause[0.25]
(*Get current distance*)
Print["Distance: "<>ToString[N[Quantity[lrf@GetDistance[],"cm"]]]]
lrf@DisableLaser[](*Turn laser off*)
ipcon@Disconnect[]
ReleaseNETObject[lrf]
ReleaseNETObject[ipcon]
|
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 | Needs["NETLink`"]
LoadNETAssembly["Tinkerforge",NotebookDirectory[]<>"../../.."]
host="localhost"
port=4223
uid="XYZ"(*Change XYZ to the UID of your Laser Range Finder Bricklet*)
(*Create IPConnection and device object*)
ipcon=NETNew["Tinkerforge.IPConnection"]
lrf=NETNew["Tinkerforge.BrickletLaserRangeFinder",uid,ipcon]
ipcon@Connect[host,port]
(*Turn laser on and wait 250ms for very first measurement to be ready*)
lrf@EnableLaser[]
Pause[0.25]
(*Callback function for distance callback*)
DistanceCB[sender_,distance_]:=
Print["Distance: "<>ToString[N[Quantity[distance,"cm"]]]]
AddEventHandler[lrf@DistanceCallback,DistanceCB]
(*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["Click OK to exit"]
lrf@DisableLaser[](*Turn laser off*)
ipcon@Disconnect[]
ReleaseNETObject[lrf]
ReleaseNETObject[ipcon]
|
Download (ExampleThreshold.nb)
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 | Needs["NETLink`"]
LoadNETAssembly["Tinkerforge",NotebookDirectory[]<>"../../.."]
host="localhost"
port=4223
uid="XYZ"(*Change XYZ to the UID of your Laser Range Finder Bricklet*)
(*Create IPConnection and device object*)
ipcon=NETNew["Tinkerforge.IPConnection"]
lrf=NETNew["Tinkerforge.BrickletLaserRangeFinder",uid,ipcon]
ipcon@Connect[host,port]
(*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]
(*Callback function for distance reached callback*)
DistanceReachedCB[sender_,distance_]:=
Print["Distance: "<>ToString[N[Quantity[distance,"cm"]]]]
AddEventHandler[lrf@DistanceReachedCallback,DistanceReachedCB]
(*Configure threshold for distance "greater than 20 cm"*)
option=Tinkerforge`BrickletLaserRangeFinder`THRESHOLDUOPTIONUGREATER
lrf@SetDistanceCallbackThreshold[option,20,0]
Input["Click OK to exit"]
lrf@DisableLaser[](*Turn laser off*)
ipcon@Disconnect[]
ReleaseNETObject[lrf]
ReleaseNETObject[ipcon]
|
Generally, every function of the Mathematica bindings that returns a value can
throw a Tinkerforge.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 plugs the
device out). However, if a wireless connection is used, timeouts will occur
if the distance to the device gets too big.
Since .NET/Link does not support multiple return values directly, we use the
out
keyword to return multiple values from a function. For further
information about the out
keyword in .NET/Link see the corresponding
Mathematica .NET/Link documentation.
The namespace for all Brick/Bricklet bindings and the IPConnection is
Tinkerforge.*
.
BrickletLaserRangeFinder
[uid, ipcon] → laserRangeFinder¶Parameters: |
|
---|---|
Returns: |
|
Creates an object with the unique device ID uid
:
laserRangeFinder=NETNew["Tinkerforge.BrickletLaserRangeFinder","YOUR_DEVICE_UID",ipcon]
This object can then be used after the IP Connection is connected.
The .NET runtime has built-in garbage collection that frees objects that are no longer in use by a program. But because Mathematica can not automatically tell when a Mathematica "program" doesn't use a .NET object anymore, this has to be done by the program. For this the ReleaseNETObject[] function is used in the examples.
For further information about object management in .NET/Link see the corresponding Mathematica .NET/Link documentation.
BrickletLaserRangeFinder
@
GetDistance
[] → distance¶Returns: |
|
---|
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[]
.
BrickletLaserRangeFinder
@
GetVelocity
[] → velocity¶Returns: |
|
---|
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[]
.
BrickletLaserRangeFinder
@
SetMode
[mode] → Null¶Parameters: |
|
---|
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:
The following constants are available for this function:
For mode:
BrickletLaserRangeFinder
@
GetMode
[] → mode¶Returns: |
|
---|
Returns the mode as set by SetMode[]
.
The following constants are available for this function:
For mode:
BrickletLaserRangeFinder
@
EnableLaser
[] → Null¶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
[] → Null¶Deactivates the laser of the LIDAR.
BrickletLaserRangeFinder
@
IsLaserEnabled
[] → laserEnabled¶Returns: |
|
---|
Returns true if the laser is enabled, false otherwise.
BrickletLaserRangeFinder
@
SetConfiguration
[acquisitionCount, enableQuickTermination, thresholdValue, measurementFrequency] → Null¶Parameters: |
|
---|
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
@
GetConfiguration
[out acquisitionCount, out enableQuickTermination, out thresholdValue, out measurementFrequency] → Null¶Output Parameters: |
|
---|
Returns the configuration as set by SetConfiguration[]
.
New in version 2.0.3 (Plugin).
BrickletLaserRangeFinder
@
SetMovingAverage
[distanceAverageLength, velocityAverageLength] → Null¶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.
BrickletLaserRangeFinder
@
GetMovingAverage
[out distanceAverageLength, out velocityAverageLength] → Null¶Output Parameters: |
|
---|
Returns the length moving average as set by SetMovingAverage[]
.
BrickletLaserRangeFinder
@
GetSensorHardwareVersion
[] → version¶Returns: |
|
---|
Returns the LIDAR-Lite hardware version.
The following constants are available for this function:
For version:
New in version 2.0.3 (Plugin).
BrickletLaserRangeFinder
@
GetIdentity
[out uid, out connectedUid, out position, out {hardwareVersion1, hardwareVersion2, hardwareVersion3}, out {firmwareVersion1, firmwareVersion2, firmwareVersion3}, out deviceIdentifier] → Null¶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.
BrickletLaserRangeFinder
@
SetDistanceCallbackPeriod
[period] → Null¶Parameters: |
|
---|
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.
BrickletLaserRangeFinder
@
GetDistanceCallbackPeriod
[] → period¶Returns: |
|
---|
Returns the period as set by SetDistanceCallbackPeriod[]
.
BrickletLaserRangeFinder
@
SetVelocityCallbackPeriod
[period] → Null¶Parameters: |
|
---|
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.
BrickletLaserRangeFinder
@
GetVelocityCallbackPeriod
[] → period¶Returns: |
|
---|
Returns the period as set by SetVelocityCallbackPeriod[]
.
BrickletLaserRangeFinder
@
SetDistanceCallbackThreshold
[option, min, max] → Null¶Parameters: |
|
---|
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
@
GetDistanceCallbackThreshold
[out option, out min, out max] → Null¶Output Parameters: |
|
---|
Returns the threshold as set by SetDistanceCallbackThreshold[]
.
The following constants are available for this function:
For option:
BrickletLaserRangeFinder
@
SetVelocityCallbackThreshold
[option, min, max] → Null¶Parameters: |
|
---|
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
@
GetVelocityCallbackThreshold
[out option, out min, out max] → Null¶Output Parameters: |
|
---|
Returns the threshold as set by SetVelocityCallbackThreshold[]
.
The following constants are available for this function:
For option:
BrickletLaserRangeFinder
@
SetDebouncePeriod
[debounce] → Null¶Parameters: |
|
---|
Sets the period with which the threshold callbacks
are triggered, if the thresholds
keep being reached.
BrickletLaserRangeFinder
@
GetDebouncePeriod
[] → debounce¶Returns: |
|
---|
Returns the debounce period as set by SetDebouncePeriod[]
.
Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a function to a callback property of the device object:
MyCallback[sender_,value_]:=Print["Value: "<>ToString[value]] AddEventHandler[laserRangeFinder@ExampleCallback,MyCallback]
For further information about event handling using .NET/Link see the corresponding Mathematica .NET/Link documentation.
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.
BrickletLaserRangeFinder
@
DistanceCallback
[sender, distance]¶Callback Parameters: |
|
---|
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.
BrickletLaserRangeFinder
@
VelocityCallback
[sender, velocity]¶Callback Parameters: |
|
---|
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.
BrickletLaserRangeFinder
@
DistanceReachedCallback
[sender, distance]¶Callback Parameters: |
|
---|
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
@
VelocityReachedCallback
[sender, velocity]¶Callback Parameters: |
|
---|
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[]
.
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
@
GetAPIVersion
[] → {apiVersion1, apiVersion2, apiVersion3}¶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.
BrickletLaserRangeFinder
@
GetResponseExpected
[functionId] → responseExpected¶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:
BrickletLaserRangeFinder
@
SetResponseExpected
[functionId, responseExpected] → Null¶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:
BrickletLaserRangeFinder
@
SetResponseExpectedAll
[responseExpected] → Null¶Parameters: |
|
---|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
BrickletLaserRangeFinder
`
DEVICEUIDENTIFIER
¶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.
BrickletLaserRangeFinder
`
DEVICEDISPLAYNAME
¶This constant represents the human readable name of a Laser Range Finder Bricklet.