Lightdiction KB2D User manual

Lightdiction
User Manual
KB2D
05/09/2015
Page 1/32
Lightdiction SAS
KB2D User Manual
March 2022 rev 2.0
KB2D Interactive Device
Laser Harp MIDI controller
The KB2D Interactive Device is a detection system working as a MIDI controller. It enables to send customizable
MIDI messages just by touching / interacting with lasers, and can be used with any scanning laser projector system
in order to create an interactive projection.
With the various detection modes available, it can be adapted to any show, from the easiest laser Harp system to
the most complete Interactive laser show. It also features laser tracking modes for laser Theremin for instance.
Thanks to an exclusive and innovative patented detection system and powerful algorithms, it is actually the most
compact, stable, competitive and versatile Laser interactive device on the market.
Footswitches or other external MIDI controllers can be used to improve the flexibility of the device during shows.

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FEATURES
➢COMPACT AND LIGHT DESIGN,EASY TO USE
➢OPEN-SOURCE SOFTWARE INTERFACE
➢CROSS-PLATFORM INTERFACE (WINDOWS,MAC,LINUX).
➢CAN BE USED WITH EXTERNAL MIDI CONTROLLERS LIKE FOOTSWITCHES FOR INSTANCE
➢POLYPHONIC DETECTION
➢LASER HARP MODE WITH UP TO 16 NOTES WITH HEIGHT MODULATION
➢CONTINUOUS MODE FOR LASER TRACKING AND MODULATIONS
➢POWER AND COMMUNICATION THROUGH USB
oUP TO 4X MIDI IN AND OUT PORTS VIA USB
oLOW POWER CONSUMPTION
➢LASER SENSITIVE
oNOT SENSITIVE TO DAYLIGHT
oEXTREMELY RESISTANT TO PARASITIC LIGHTS
oPERFECT FOR USE ON LIVE SHOWS
➢HIGHLY VERSATILE AND FLEXIBLE SYSTEM
oCAN BE USED WITH ANY LASER PROJECTOR
oNO SYNCHRONIZATION OR COMMUNICATION WITH THE LASER
oPOSITION,HEIGHT AND WIDTH DETECTION FOR CUSTOM INTERACTIVE SCENES
oTHE SOFTWARE INTERFACE CAN BE CONNECTED TO ANY EXTERNAL MIDI DEVICE
➢VERY HIGH DETECTION RANGE WITH PROGRAMMABLE AMPLIFICATION FOR LONG DISTANCE INTERACTIVE SHOWS
TYPICAL APPLICATIONS
➢LASER HARP
➢LASER TRACKING
➢INTERACTIVE LASER SHOWS
➢INTERACTIVE GAMES

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User Manual
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TABLE OF CONTENT
I. Presentation of the device.......................................................................................................................................4
1. Technical specifications ......................................................................................................................................4
2. Setup of the KB2D ...............................................................................................................................................5
3. How does it work?................................................................................................................................................6
II. KB2D Laser Harp Interface .....................................................................................................................................7
1. Download and install ...........................................................................................................................................7
2. First start ..............................................................................................................................................................8
3. DESCRIPTION of the interface.......................................................................................................................... 10
Button bar.............................................................................................................................................................. 10
MIDI Ports Settings ............................................................................................................................................... 11
KB2D Ports............................................................................................................................................................ 12
Beam Angles configuration .................................................................................................................................. 13
MIDI Effects Configuration.................................................................................................................................... 14
Generic settings .................................................................................................................................................... 18
External MIDI Mapping ......................................................................................................................................... 24
Firmware Updater ................................................................................................................................................. 26
III. HOW TO QUICKLY SET A LASER HARP SYSTEM .............................................................................................. 28
1. Install The KB2D User Interface....................................................................................................................... 28
2. Place the KB2D ................................................................................................................................................. 28
3. Connect the KB2D and start the interface...................................................................................................... 28
4. Start your favorite DAW..................................................................................................................................... 29
5. Select the notes you want ................................................................................................................................ 29
6. Calibrate detection parameters ....................................................................................................................... 29
7. Calibrate angles ................................................................................................................................................ 29
IV. PRECAUTIONS AND RECOMMANDATIONS ON USE ........................................................................................ 30
V. COMMON ISSUES.................................................................................................................................................. 31
VI. Please read carefully: ....................................................................................................................................... 32
VII. Revision History................................................................................................................................................. 32

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I. PRESENTATION OF THE DEVICE
1. TECHNICAL SPECIFICATIONS
Parameter
Comment
Min
Typical
Max
Electrical Specifications
Vin
Voltage, USB Powered
4.5V
5V
6V
Iin
Current consumption
-
60mA
-
Detection Specifications
FPS
Frames Per Second on detection
(Set by User)
50
-
130
BW
Bandwidth on beam detection
(Works with scanning systems)
5 Hz
50 kHz
Ddet
Detection distance of interactions (*)
0.3m (1)
0.8m (2)
-
~10m (1)
~25m (2)
X
Detection angle (can be customized on demand)
-35°
-
35°
Angle accuracy
1 mrad

Wavelength detected - By default
320nm
-
1100nm

Wavelength detected –Optional
510nm
520nm
535nm

Wavelength detected –Optional
625nm
635nm
-

Wavelength detected –Optional
370nm
445nm
470nm
Maximum ambient light
1000 lux
Mechanical / Housing Specifications
L x W x H
Length x Width x Height (mm)
(Without the Handle)
100 x 32 x 58
msys
Weight
155g
IP
Ingress Protection
IP44
(*) When interacting with a Lambertian white target with ~80% reflectance
(1) With a 3W laser projector. Maximum is obtained using the x16 software amplification.
(2) With a 20W laser projector. Maximum is obtained using the x16 software amplification.

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2. SETUP OF THE KB2D
The KB2D is a detection system that can be used with any scanning laser projector. The KB2D is not
communicating with the projector, so there is no direct dependency between the KB2D and the projector.
To create a laser interactive scene, you only need:
➢A laser projector to project the pattern you want to interact with.
➢The KB2D interactive device with a USB (A –B) cable.
➢A computer with Windows 10 or above with the KB2D Laser Harp Interface. The last KB2D setup can be
downloaded at https://lightdiction.com/Ressources/ .
Fig. 1: Typical installation of the KB2D interactive device for a laser Harp application.
•In order to improve the accuracy, the KB2D should be aligned with the (virtual) cross of the beams.
•The length of the KB2D device must be parallel to the plane formed by the beams.
USB (A –B)
2
D
KB2D
Laser
Projector

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3. HOW DOES IT WORK?
The KB2D is detecting the position angle of each incident light interaction. With the help of a complex algorithm,
it can then precisely separate each laser beam from parasitic light source, and send a MIDI signal associated with
a specific interaction. Multiple interactions can be detected simultaneously (so it is possible to play a “polyphonic”
laser Harp for instance).
Interactions can be detected in a 3D environment, but position measurement is in 2 dimensions with the KB2D.
The X (angle) and Z (distance) variables correspond to the coordinates of the interaction. The “Width” variable also
gives an information on the width of the interaction.
Fig. 2: The 2 dimensions on detection with KB2D.
Every interaction in the blue plane will have the same “Position” coordinate. The “height” coordinate is determined
in function of the luminous power received by the KB2D, which is directly correlated with the distance between the
interaction and the KB2D module. Thus, it can introduce a variation on Z height coordinate if the laser source has
not a constant emission power.
The KB2D also detects the width of each interaction, and can send a MIDI signal varying in function of the width.
As the KB2D is measuring the angle and not just detecting light (or laser) interactions, it does not have to be
synchronized with the scanning system of the laser source.

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II. KB2D LASER HARP INTERFACE
1. DOWNLOAD AND INSTALL
The latest version can be found here:
https://lightdiction.com/Ressources/
The KB2D Laser Harp interface is an open-source software. The code can be found here:
https://github.com/Lightdiction/KB2D_Interface_V3
It is recommended to always use the latest version of the Firmware and of the KB2D Laser Harp Interface, to
benefit from all the performances and options available. If the computer running the KB2D Laser Harp Interface
is connected to the internet, all available firmware and software updates will be automatically proposed at the
start of the software.
To install the software, simply start the setup file.

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2. FIRST START
Connect your KB2D on your computer, it will automatically install the standard MIDI Driver. Once your KB2D is
connected and the driver installed, you can start the KB2D Laser Harp Interface.
If your KB2D is connected and correctly recognized by the interface, it should show an information window at the
start of the interface, showing some information like the Serial Number and firmware version of your KB2D
controller.
Fig. 3: Information window when we start the interface with the KB2D connected
If for some reason the KB2D is detected but the ports are not available, you will see this kind of warning window:
Fig. 4: Warning window if MIDI ports are detected but are not available
This generally happens when another software took the control of the KB2D. For instance, if your DAW is started,
it may have taken the control automatically. Simply deactivate the reserved ports in your DAW, so the KB2D Laser
Harp Interface can connect to these:
The reserved ports are the following:
-MIDI IN 2 –KB2D Interactive
-MIDI OUT –KB2D Interactive
Or you can also close other MIDI software then start the KB2D Laser Harp Interface in priority so it takes the control
of the port.
Then, the interface opens and read all parameters in the KB2D. It should look like this:

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Fig. 5: KB2D Laser Harp Interface when the device is detected and successfully connected
If no device is found, the interface is almost empty like this:
Fig. 6: KB2D Laser Harp Interface when no device is found

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3. DESCRIPTION OF THE INTERFACE
Button bar
At the top of the interface, we have the button bar:
Fig. 7: Button bar
Button
Description
Start / Pause
Enable or disable the detection of the KB2D. When the KB2D is started, we see a light
on the button next to the USB connector on the KB2D.
We can also manually go to Start state by pressing this same button on the KB2D device.
Restart
Force the KB2D to restart. If parameters are not saved in the KB2D, changes will be lost.
Restore Defaults
Restore defaults parameters, except the number of MIDI ports.
Save in KB2D
Save all parameters in the FLASH memory of the KB2D. So, the KB2D will restore these
parameters after a restart or a loss of power.
Detection
Assistant
Opens the detection assistant window. This helps to set the detection threshold and
Speed parameters automatically (Min interaction time, Max interaction duration).
Calibrate Angles
Opens an assistant to calibrate automatically all the beams by interacting with the first
beam and the last beam. All intermediary beam angles will be deduced from this.
Learn One Angle
Calibrate one beam in particular. Click on this button, then select the number of the
beam you want to learn to measure its position angle. This enables to have a better
accuracy for intermediary beams, in comparison with “Calibrate angles”.
Learn All –One by
One
Equivalent to click on Learn One Angle for all beams. This is recommended to calibrate
all the beams in laser harp mode, with a very good accuracy.
Invert X Notes
Invert all angles, so the notes and position variables
MIDI Ports
Settings
Opens a window to access and customize all MIDI connections: KB2D Ports, External
Mapping Ports, and MIDI Bridge to connect an Input port to an Output one.
About
Show some information about the version of the software.

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MIDI Ports Settings
This window can be accessed by clicking on “MIDI Ports Settings” button on the button bar.
Fig. 8: MIDI Ports Settings window
Command
Description
Update All MIDI devices
Updates the list of all MIDI Devices available.
KB2D (MIDI In Feedback)
Select the MIDI port corresponding to the KB2D for the feedback (generally
this is the 2nd input port of the KB2D). Changing this may result in an
incorrect communication with the KB2D.
KB2D (MIDI Out Commands)
Select the MIDI port corresponding to the KB2D for the commands sent to
the device. By default, it Is the 1st output port of the KB2D. Changing this
may result in an incorrect communication with the KB2D.
External mapping (MIDI In)
MIDI Input port used for the external mapping in the interface.
External mapping (MIDI Out)
MIDI Output port used as a MIDI through for the external mapping in the
interface. All MIDI messages received by the input for the mapping are sent
to this output.
MIDI Bridge (MIDI In / Out)
Select a MIDI Input that you want to connect directly to a MIDI Output. All
messages received by the input are sent to the output. This is useful to
connect 2 hardware together. For instance, we can use this bridge to
connect the KB2D (Input 1) to an external hardware Synth.
Accept / Cancel
Accept or cancel changes and close the window.

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KB2D Ports
The KB2D Ports section gives information about the connected hardware.
Fig. 9: KB2D Ports section
Once the KB2D ports have been opened, if the communication succeeded, the ports are locked to avoid
disconnecting these by mistake. We normally do not need to select anything in these ports. The connection is done
automatically if the correct ports are detected.
KB2D Ports Enabled lets you select the number of Ports you want to use for the KB2D. By default, the KB2D uses
2 In / 2 Out.
Indeed, 1 In and 1 Out is used for the feedback + command. One other Output of the KB2D is used to send the
MIDI signals corresponding to the interaction and effects.
We can select 3 In / 3 Out or even 4 In / 4 Out to be able to create additional effects. This way we can have a
configuration with 1 output of the KB2D connected to a DAW for instance, another one to a laser software to
control the laser projector itself, and another output connected to the Bridge (connected to a hardware synth) for
instance.
The MIDI messages sent by each port of the KB2D can be customized individually.
Here is a typical connection diagram of MIDI ports, with a 2 In / 2 Out configuration:
KB2D Controller
Signal (out)
Feedback (out)
Commands (input)
Laser Harp User Interface
MIDI In (KB2D_2) Feedback
MIDI Out (KB2D) Command
MIDI In (Ext.)
DAW (Digital Audio Workstation)
MIDI In
KB2D Interactive
KB2D Interactive
MIDIIN2 (KB2DInteractive)
Footswitch / MIDI Controller Out

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Beam Angles configuration
Fig. 10: Beam Angles configuration
The Beam Angles configuration section gives you information and commands about the number of beams used
and their position.
Command
Description
Number of beams
Select the number of beams you want to interact with. The maximum number of
beams is 16. This value is useful only for discrete beam detection.
For continuous detection (with Position variable), this number of beams is not
relevant.
Enable Angle filter
(mrad)
When the angle filter is enabled, a detection is considered as valid only if it
corresponds to the angular position of a beam +/- the value of this filter.
When disabled, all detections are valid. The valid beam will be the closest one to the
angle measured.
Angle
Gives some information about the position angle in mrad. This value should not be
considered as an absolute mrad value, but more as an arbitrary unit close to a mrad.
The maximum detected angle can go up to +/- 500 mrad.
For the Position variable, the minimum and maximum of the Position correspond to
the angle of the first beam and last beam.
Click to learn
Click to learn a beam (just like the “Learn One Angle” of the Button bar).

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MIDI Effects Configuration
This is probably the most important section of the interface. This is where you do all the settings regarding the
messages you want to send to each port of the KB2D.
There is one tab for MIDI Effects Configuration for each port of the KB2D you have activated (1 in 2/2 mode, 2 in
3/3 mode, 3 in 4/4 mode, since 1 port In and Out is reserved for the control and feedback).
Fig. 11: MIDI Effects tabs in 3In/3Out mode. 2 Tabs are enabled.
Click on the tab you want to configure. All the tabs are the same and can be configured for each port.
At the top of this section, we have the Enable beams buttons.
Fig. 12: Enable beams buttons
By clicking on these buttons, we can activate a specific beam, or disable it. By default, all beams are activated
(yellow background). This option can be useful when we use multiple ports. We can activate a beam on a MIDI port
(for sounds for instance), but disable this same beam for visual effects, on another ports.
Just below, we have the effect selection section.
This is where you decide how you want the KB2D to interact with the beams.
Fig. 13: Effect selection section
On the left, we can enable or disable Note On/Off effect. This is a particular effect, as when there is an interaction,
it will send a Note On. When the interaction stops, it sends the corresponding note off.
On the middle and on the right, we can add MIDI effects on interaction. These effects can be one of a standard
type of MIDI message: Poly Aftertouch, Control Change, Program Change, Channel Aftertouch, Pitch Bend.
We can activate the Note On / Off and 2 MIDI effects on each channel, at the same time, if we want so.
This means the KB2D can create up to 9 types of MIDI interaction at the same time (3 MIDI interactions by port,
on 3 ports).
As a MIDI message is composed of 3 values, we can decide what we want to put on these values.
The first value is the Channel.
Fig. 14: Channel selection

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We can select here the Channel where we want the effect to play. The channel goes from 1 to 16. We can select
a fixed value, or we can select a Variable called “N° beam”.
By selecting this variable, you indicate to the KB2D that you want the value to change in function of the beam you
interact with. When you interact with the first beam, it will be channel 1. If you have 16 beams and you interact
with beam number 16, It will send 16.
The second value is the Note or Control:
Fig. 15: Note / control selection
This second value can vary from 0 to 127. Here again, we can choose a fixed value, or we can select a variable:
Variable
Description
Keyboard
Select this variable to be able to assign a value on each beam. To ease the selection
of the value, a keyboard will be displayed, so you select the note you want on each
beam. Then, the interface will automatically make the conversion between the note
you chose, and its MIDI value.
Combos
Just like the Keyboard variable, “Combos” lets you decide the value you want to
assign to each beam. The difference is about the way you select the value. With
“Combos”, you have to select directly the value you want, from 0 to 127 (by default).
Position
This variable will vary from continuously from 0 to 127 (by default) in function of the
position (angle) where you interact with beam. 0 correspond to the angle of the first
beam. 127 correspond to the position of the last beam. Let’s say we project a
continuous line; we can track the position of the interaction in function of the value of
this variable. On a large interaction, or if you interact on multiple points at the same
time (polyphonic), the position value will be the median of the extreme values.
Height
This variable will vary continuously from 0 to 127 in function of the height of the
interaction. By default, in relative mode, the value will be 64 when you start
interaction. Then it goes up or down in function of the variation of the height after the
interaction. If you interact on multiple height at the same time (polyphonic), the value
of the height will correspond to the average height.
Width
As an interaction is never punctual, this variable corresponds to the width of the
interaction. 0 is a punctual interaction. 127 is an interaction that goes from the angle
of the first beam to the angle of the last beam.
When interacting on multiple position at the same time, the width corresponds to the
maximum distance covered by all the interactions.

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Glide
Glide is a test variable, currently not used.
The third value is the Velocity or Effect value.
The third value has the same options as the second value.
Application example:
For a Basic Harp application, with pitch variation with height, we can set the following parameters:
Fig. 16: Configuration example for a Harp application
We enable Notes On/Off for sure. We select Channel 1 for instance. As we want to choose the notes played on
each beam, we will select the “Keyboard” variable for the note value. And we will set the velocity to a fixed value:
127 to have it at full volume.
For the pitch effect with height, we enable one of the effects, and we select “Pitch” in the drop-down menu. Then,
we also select the Channel 1 (for instance), and we put the control to 0. Then we will let the value of this pitch vary
in function of the height, so we select “Height” as the variable for the value.
Below, we have the Keyboard (if the “keyboard” variable is selected)
Fig. 17: Keyboard section
This section is shown only if the “Keyboard” variable is used.
A keyboard is displayed. The keys currently used are colored in yellow, and the corresponding beam number is
indicated on the key.
We also have a few options and buttons:

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Variable
Description
+1/2 tone
-1/2 tone
+1 tone
-1 tone
These buttons are quite explicit. This shifts all current notes selected up or down.
User 1 / 2 / 3
These buttons load note values that have been saved previously. This user presets
are saved locally on the computer, not in the KB2D.
Select Preset
You can select and load here any custom preset you saved previously.
Save Preset…
Click to save the current notes configuration to a preset of your choice. You can save
to a User preset (1, 2 or 3), or to a custom preset that you can also name as you want.
Manage presets…
Open a window to let you manage your presets currently saved: switch presets, delete
preset, rename preset, and so on.
Select beam to
assign
Click here on the beam index you want, then click to a key on the keyboard to assign
the key to the index.
You can also click on “All” to assign all beams one by one, starting with the first or the
one currently selected.
[Click on a key]
By clicking on a key of the keyboard, this will send the note. This is also a way to
check if your KB2D is correctly connected to your DAW or synth.
Also, clicking on the Key will let you choose the beam you want to assign to this note.
This is an alternative method to assign a key to a beam.
Select Note on a click
If you uncheck this box, the note will not be sent when you click on a key of the
keyboard. (But you can still assign a note to a beam index by clicking on the key).
First Key
Select the first key shown on the keyboard.
Number of keys
Select the number of keys you want to be shown on the keyboard.
Combos section (only if the “Combos” variable is selected)
Fig. 18: Combos section
This section is shown only if the “Combos” variable is used.
Drop down menus are shown for each beam. Each drop down has a value going from 0 to 127. You can select the
value you want directly here on each combo.

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Generic settings
The generic settings are in the panel at the right of the interface.
The size of this panel can be adjusting by clicking and moving on its left edge.
Preset modes
At the top of this panel, we have the preset modes:
Fig. 19: Preset modes
This section lets you switch quickly between some preset modes. This also helps at the beginning to show you
some examples, if you do not know how to set the KB2D.
Variable
Description
Basic Harp
This mode sets a basic harp mode, with only notes On and Off activated when you
interact with the beams.
Harp + Height
This mode is the basic harp, but with the height also enabled.
Tracking effects
This just enables a position varying effect, so you can use it to track your interaction.
It should be used with a line pattern on the laser.
Theremin
This enables a Theremin mode, with a fixed note being played, a pitch varying with the
position and a CC effect varying with the width. It should be used with a line pattern
on the laser.
Detection settings
Just below we have the detection settings:
Fig. 20: Detection settings section
This section lets you adjust the following parameters regarding the detection. Some of these parameters (detection
threshold, Min interaction time, Max interaction duration) are set automatically when you use the detection
assistant, but you can still adjust these manually in order to optimize the detection.

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Parameter
Description
Hardware Gain
This is an additional amplification on the KB2D electronic board, that can be selected
with the software. By default, there is no additional amplification, but if the detection
threshold is very low (less than 100), you can enable a x2, x4, x8 or x16 amplification.
This can also be useful for long distance interactions in some configurations.
Frames Per Second
Set the detection frame rate. This should be close are slightly less than the frame rate
of your laser pattern.
Detection threshold
This is the minimum value (arbitrary unit) of lighting power that the sensor needs to
receive to consider an interaction as potentially valid.
If this value is too low, the KB2D can detection other elements in the environment,
like the background (ceiling if you project your laser vertically indoor).
If this value is too high, the system will have difficulties to detect your hand or the
object you want to interact with.
Min interaction time
To be considered as valid, an interaction has to last a minimum time specified by this
parameter (arbitrary unit). This parameter can help to filter some parasitic lights (like
short flash from cameras, for instance).
Max interaction time
This qualify the maximum time an interaction should last to be considered as valid (in
1 frame).
In most environments, this parameter is not very useful, and you can set it at an
intermediary value.
Note Off release
This is the number of frames before a note turns Off, when you start interacting with a
beam (or when a beam is not detected). In particular, it is useful if the frame rate set
in your interface is approximative. It will avoid parasitic Note Off messages when you
interact with a beam. If the value is too high, it will introduce a latency on the note off.
A value of 4 is generally good, and we don’t really feel the latency.
Height settings
Just below we have the height settings:
Fig. 21: Height settings section

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This section lets you adjust the settings related to the “Height” variable.
Parameter
Description
Min Height /
Intermediate / Max
Height
Assign the minimum and maximum value the height can take. The intermediate value
corresponds to the initial value the Height takes when you start interacting (in relative
mode).
Substitute Height
value
The substitute value is sent when we stop interacting with the beams, instead of
keeping the last value. This is a kind of “Note Off” for effect.
Invert Height
modulation
By default, the minimum value corresponds to an interaction far from the sensor, and
the maximum value is close to the sensor. Check this box to invert the variation.
Height modulation
Type of modulation (relative or absolute). Relative modulation always starts with the
intermediate value, and then varies in function of the height variation.
Absolute modulation corresponds to the absolute power value received by the sensor.
Currently, absolute variation is not fully functional and should not be used.
Amplitude (sensitivity)
The Amplitude is the amount of variation in function of the height. If this value is high,
the height variable will vary faster.
Smoothing filter
This is used to avoid brutal variation of the height variable in function od the height. If
the smoothing filter is high, the height variable will vary very slowly.
It is recommended to not set it too low, or you could have brutal variation when
removing your hand for instance.
Attack filter
This sets the minimum number of frames before the KB2D starts modulating. It
avoids to have incorrect values at the start of the interaction, you should keep it quite
high preferably.
Stabilization delta
This sets in area around the initial height where the variable will keep the
intermediate value and will not modulate. This lets you play easily without having a
modulation constantly when you are trying to play the exact note without modulation.