Mathematica - LED Strip Bricklet

This is the description of the Mathematica API bindings for the LED Strip Bricklet. General information and technical specifications for the LED Strip Bricklet are summarized in its hardware description.

An installation guide for the Mathematica API bindings is part of their general description.

Examples

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

Simple

Download (ExampleSimple.nb)

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Needs["NETLink`"]
LoadNETAssembly["Tinkerforge",NotebookDirectory[]<>"../../.."]

host="localhost"
port=4223
uid="jEE"(* Change to your UID *)

(* Create IPConnection and device object *)
ipcon=NETNew["Tinkerforge.IPConnection"]
ls=NETNew["Tinkerforge.BrickletLEDStrip",uid,ipcon]
ipcon@Connect[host,port]

(* Set first 10 LEDs to green *)
r={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
g={255,255,255,255,255,255,255,255,255,255,0,0,0,0,0,0}
b={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
ls@SetRGBValues[0,10,r,g,b]

(* Clean up *)
ipcon@Disconnect[]
ReleaseNETObject[ls]
ReleaseNETObject[ipcon]

Callback

Download (ExampleCallback.nb)

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Needs["NETLink`"]
LoadNETAssembly["Tinkerforge",NotebookDirectory[]<>"../../.."]

host="localhost"
port=4223
uid="jEE"(* Change to your UID *)

(* Create IPConnection and device object *)
ipcon=NETNew["Tinkerforge.IPConnection"]
ls=NETNew["Tinkerforge.BrickletLEDStrip",uid,ipcon]
ipcon@Connect[host,port]

(* Set frame duration to 50ms (20 frames per second) *)
ls@SetFrameDuration[50]

numLEDs=16
rIndex=1
r={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
g={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
b={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}

(* Frame rendered callback,is called when a new frame was rendered *)
(* We increase the index of one blue LED with every frame *)
FrameRenderedCB[sender_,length_]:=
 Module[{},
  b[[rIndex]]=0;
  If[rIndex==numLEDs,rIndex=1,rIndex=rIndex+1];
  b[[rIndex]]=255;

  (* Set new data for next render cycle *)
  sender@SetRGBValues[0,numLEDs,r,g,b]
 ]

AddEventHandler[ls@FrameRendered,FrameRenderedCB]

(* Set initial rgb values to get started *)
ls@SetRGBValues[0,numLEDs,r,g,b]

Input["Click OK to exit"]

(* Clean up *)
ipcon@Disconnect[]
ReleaseNETObject[ls]
ReleaseNETObject[ipcon]

API

Generally, every method 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 method. 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.*.

Basic Functions

BrickletLEDStrip[uid, ipcon] → ledStrip
Parameters:
  • uid -- String
  • ipcon -- NETObject[IPConnection]
Returns:
  • ledStrip -- NETObject[BrickletLEDStrip]

Creates an object with the unique device ID uid:

ledStrip=NETNew["Tinkerforge.BrickletLEDStrip","YOUR_DEVICE_UID",ipcon]

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

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.

BrickletLEDStrip@SetRGBValues[index, length, {r1, r2, ..., r16}, {g1, g2, ..., g16}, {b1, b2, ..., b16}] → Null
Parameters:
  • index -- Integer
  • length -- Integer
  • ri -- Integer
  • gi -- Integer
  • bi -- Integer

Sets the rgb values for the LEDs with the given length starting from index.

The maximum length is 16, the index goes from 0 to 319 and the rgb values have 8 bits each.

Example: If you set

  • index to 5,
  • length to 3,
  • r to [255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
  • g to [0, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] and
  • b to [0, 0, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

the LED with index 5 will be red, 6 will be green and 7 will be blue.

Note

Depending on the LED circuitry colors can be permuted.

The colors will be transfered to actual LEDs when the next frame duration ends, see SetFrameDuration[].

Generic approach:

  • Set the frame duration to a value that represents the number of frames per second you want to achieve.
  • Set all of the LED colors for one frame.
  • Wait for the FrameRendered callback.
  • Set all of the LED colors for next frame.
  • Wait for the FrameRendered callback.
  • and so on.

This approach ensures that you can change the LED colors with a fixed frame rate.

The actual number of controllable LEDs depends on the number of free Bricklet ports. See here for more information. A call of SetRGBValues[] with index + length above the bounds is ignored completely.

BrickletLEDStrip@GetRGBValues[index, length, out {r1, r2, ..., r16}, out {g1, g2, ..., g16}, out {b1, b2, ..., b16}] → Null
Parameters:
  • index -- Integer
  • length -- Integer
  • ri -- Integer
  • gi -- Integer
  • bi -- Integer

Returns the rgb with the given length starting from the given index.

The values are the last values that were set by SetRGBValues[].

BrickletLEDStrip@SetFrameDuration[duration] → Null
Parameters:
  • duration -- Integer

Sets the frame duration in ms.

Example: If you want to achieve 20 frames per second, you should set the frame duration to 50ms (50ms * 20 = 1 second).

For an explanation of the general approach see SetRGBValues[].

Default value: 100ms (10 frames per second).

BrickletLEDStrip@GetFrameDuration[] → duration
Returns:
  • duration -- Integer

Returns the frame duration as set by SetFrameDuration[].

BrickletLEDStrip@GetSupplyVoltage[] → voltage
Returns:
  • voltage -- Integer

Returns the current supply voltage of the LEDs. The voltage is given in mV.

BrickletLEDStrip@SetClockFrequency[frequency] → Null
Parameters:
  • frequency -- Integer

Sets the frequency of the clock in Hz. The range is 10000Hz (10kHz) up to 2000000Hz (2MHz).

The Bricklet will choose the nearest achievable frequency, which may be off by a few Hz. You can get the exact frequency that is used by calling GetClockFrequency[].

If you have problems with flickering LEDs, they may be bits flipping. You can fix this by either making the connection between the LEDs and the Bricklet shorter or by reducing the frequency.

With a decreasing frequency your maximum frames per second will decrease too.

The default value is 1.66MHz.

Note

The frequency in firmware version 2.0.0 is fixed at 2MHz.

New in version 2.0.1 (Plugin).

BrickletLEDStrip@GetClockFrequency[] → frequency
Returns:
  • frequency -- Integer

Returns the currently used clock frequency as set by SetClockFrequency[].

New in version 2.0.1 (Plugin).

BrickletLEDStrip@SetChipType[chip] → Null
Parameters:
  • chip -- Integer

Sets the type of the led driver chip. We currently support the chips

  • WS2801 (chip = 2801),
  • WS2811 (chip = 2811) and
  • WS2812 (chip = 2812).

The WS2812 is sometimes also called "NeoPixel", a name coined by Adafruit.

The default value is WS2801 (chip = 2801).

The following constants are available for this function:

  • BrickletLEDStrip`CHIPUTYPEUWS2801 = 2801
  • BrickletLEDStrip`CHIPUTYPEUWS2811 = 2811
  • BrickletLEDStrip`CHIPUTYPEUWS2812 = 2812

New in version 2.0.2 (Plugin).

BrickletLEDStrip@GetChipType[] → chip
Returns:
  • chip -- Integer

Returns the currently used chip type as set by SetChipType[].

The following constants are available for this function:

  • BrickletLEDStrip`CHIPUTYPEUWS2801 = 2801
  • BrickletLEDStrip`CHIPUTYPEUWS2811 = 2811
  • BrickletLEDStrip`CHIPUTYPEUWS2812 = 2812

New in version 2.0.2 (Plugin).

Advanced Functions

BrickletLEDStrip@GetAPIVersion[] → {apiVersion1, apiVersion2, apiVersion3}
Returns:
  • apiVersioni -- Integer

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.

BrickletLEDStrip@GetResponseExpected[functionId] → responseExpected
Parameters:
  • functionId -- Integer
Returns:
  • responseExpected -- True/False

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.

BrickletLEDStrip@SetResponseExpected[functionId, responseExpected] → Null
Parameters:
  • functionId -- Integer
  • responseExpected -- True/False

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:

  • BrickletLEDStrip`FUNCTIONUSETURGBUVALUES = 1
  • BrickletLEDStrip`FUNCTIONUSETUFRAMEUDURATION = 3
  • BrickletLEDStrip`FUNCTIONUSETUCLOCKUFREQUENCY = 7
  • BrickletLEDStrip`FUNCTIONUSETUCHIPUTYPE = 9
BrickletLEDStrip@SetResponseExpectedAll[responseExpected] → Null
Parameters:
  • responseExpected -- True/False

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

BrickletLEDStrip@GetIdentity[out uid, out connectedUid, out position, out {hardwareVersion1, hardwareVersion2, hardwareVersion3}, out {firmwareVersion1, firmwareVersion2, firmwareVersion3}, out deviceIdentifier] → Null
Parameters:
  • uid -- String
  • connectedUid -- String
  • position -- Integer
  • hardwareVersioni -- Integer
  • firmwareVersioni -- Integer
  • deviceIdentifier -- Integer

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.

Callbacks

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:

Callback[sender_,value_]:=Print["Value: "<>ToString[value]]

AddEventHandler[ledStrip@Example,Callback]

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.

event BrickletLEDStrip@FrameRendered[sender, length]
Parameters:
  • sender -- NETObject[BrickletLEDStrip]
  • length -- Integer

This callback is triggered directly after a new frame is rendered.

You should send the data for the next frame directly after this callback was triggered.

For an explanation of the general approach see SetRGBValues[].

Constants

BrickletLEDStrip`DEVICEUIDENTIFIER

This constant is used to identify a LED Strip Bricklet.

The GetIdentity[] function and the EnumerateCallback callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

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