Mathematica - RS232 Bricklet

This is the description of the Mathematica API bindings for the RS232 Bricklet. General information and technical specifications for the RS232 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).

Loopback

Download (ExampleLoopback.nb)

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

(*For this example connect the RX1 and TX pin to receive the send message*)

host="localhost"
port=4223
uid="XYZ"(*Change XYZ to the UID of your RS232 Bricklet*)

(*Create IPConnection and device object*)
ipcon=NETNew["Tinkerforge.IPConnection"]
rs232=NETNew["Tinkerforge.BrickletRS232",uid,ipcon]
ipcon@Connect[host,port]

(*Convert string to char array with length 60,as needed by write*)
StringToCharList[message_]:=PadRight[ToCharacterCode[message],60,0]

(*Assume that the message consists of ASCII characters and*)
(*convert it from an array of chars to a string*)
CharListToString[message_,length_]:=StringTake[FromCharacterCode[message],length]

(*Callback function for read callback *)
ReadCB[sender_,message_,length_]:=
 Print["Message (Length: "<>ToString[N[length]]<>"): "<>
       CharListToString[message,length]]
AddEventHandler[rs232@ReadCallback,ReadCB]

(*Enable read callback*)
rs232@EnableReadCallback[]

(*Write "test" string*)
message:="test"
(*FIXME: This call crashes Mono with a SIGSEGV, no clue why*)
rs232@Write[StringToCharList[message],StringLength[message]]

Input["Click OK to exit"]

(*Clean up*)
ipcon@Disconnect[]
ReleaseNETObject[rs232]
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

BrickletRS232[uid, ipcon] → rs232
Parameters:
  • uid -- String
  • ipcon -- NETObject[IPConnection]
Returns:
  • rs232 -- NETObject[BrickletRS232]

Creates an object with the unique device ID uid:

rs232=NETNew["Tinkerforge.BrickletRS232","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.

BrickletRS232@Write[{message1, message2, ..., message60}, length] → written
Parameters:
  • messagei -- Integer
  • length -- Integer
Returns:
  • written -- Integer

Writes a string of up to 60 characters to the RS232 interface. The string can be binary data, ASCII or similar is not necessary.

The length of the string has to be given as an additional parameter.

The return value is the number of bytes that could be written.

See SetConfiguration[] for configuration possibilities regarding baudrate, parity and so on.

BrickletRS232@Read[out {message1, message2, ..., message60}, out length] → Null
Parameters:
  • messagei -- Integer
  • length -- Integer

Returns the currently buffered message. The maximum length of message is 60. If the length is given as 0, there was no new data available.

Instead of polling with this function, you can also use callbacks. See EnableReadCallback[] and ReadCallback callback.

BrickletRS232@SetConfiguration[baudrate, parity, stopbits, wordlength, hardwareFlowcontrol, softwareFlowcontrol] → Null
Parameters:
  • baudrate -- Integer
  • parity -- Integer
  • stopbits -- Integer
  • wordlength -- Integer
  • hardwareFlowcontrol -- Integer
  • softwareFlowcontrol -- Integer

Sets the configuration for the RS232 communication. Available options:

  • Baudrate between 300 and 230400 baud.
  • Parity of none, odd, even or forced parity.
  • Stopbits can be 1 or 2.
  • Word length of 5 to 8.
  • Hard-/Software flow control can either be on or off but not both simultaneously on.

The default is: 115200 baud, parity none, 1 stop bit, word length 8, hard-/software flow control off.

The following constants are available for this function:

  • BrickletRS232`BAUDRATEU300 = 0
  • BrickletRS232`BAUDRATEU600 = 1
  • BrickletRS232`BAUDRATEU1200 = 2
  • BrickletRS232`BAUDRATEU2400 = 3
  • BrickletRS232`BAUDRATEU4800 = 4
  • BrickletRS232`BAUDRATEU9600 = 5
  • BrickletRS232`BAUDRATEU14400 = 6
  • BrickletRS232`BAUDRATEU19200 = 7
  • BrickletRS232`BAUDRATEU28800 = 8
  • BrickletRS232`BAUDRATEU38400 = 9
  • BrickletRS232`BAUDRATEU57600 = 10
  • BrickletRS232`BAUDRATEU115200 = 11
  • BrickletRS232`BAUDRATEU230400 = 12
  • BrickletRS232`PARITYUNONE = 0
  • BrickletRS232`PARITYUODD = 1
  • BrickletRS232`PARITYUEVEN = 2
  • BrickletRS232`PARITYUFORCEDUPARITYU1 = 3
  • BrickletRS232`PARITYUFORCEDUPARITYU0 = 4
  • BrickletRS232`STOPBITSU1 = 1
  • BrickletRS232`STOPBITSU2 = 2
  • BrickletRS232`WORDLENGTHU5 = 5
  • BrickletRS232`WORDLENGTHU6 = 6
  • BrickletRS232`WORDLENGTHU7 = 7
  • BrickletRS232`WORDLENGTHU8 = 8
  • BrickletRS232`HARDWAREUFLOWCONTROLUOFF = 0
  • BrickletRS232`HARDWAREUFLOWCONTROLUON = 1
  • BrickletRS232`SOFTWAREUFLOWCONTROLUOFF = 0
  • BrickletRS232`SOFTWAREUFLOWCONTROLUON = 1
BrickletRS232@GetConfiguration[out baudrate, out parity, out stopbits, out wordlength, out hardwareFlowcontrol, out softwareFlowcontrol] → Null
Parameters:
  • baudrate -- Integer
  • parity -- Integer
  • stopbits -- Integer
  • wordlength -- Integer
  • hardwareFlowcontrol -- Integer
  • softwareFlowcontrol -- Integer

Returns the configuration as set by SetConfiguration[].

The following constants are available for this function:

  • BrickletRS232`BAUDRATEU300 = 0
  • BrickletRS232`BAUDRATEU600 = 1
  • BrickletRS232`BAUDRATEU1200 = 2
  • BrickletRS232`BAUDRATEU2400 = 3
  • BrickletRS232`BAUDRATEU4800 = 4
  • BrickletRS232`BAUDRATEU9600 = 5
  • BrickletRS232`BAUDRATEU14400 = 6
  • BrickletRS232`BAUDRATEU19200 = 7
  • BrickletRS232`BAUDRATEU28800 = 8
  • BrickletRS232`BAUDRATEU38400 = 9
  • BrickletRS232`BAUDRATEU57600 = 10
  • BrickletRS232`BAUDRATEU115200 = 11
  • BrickletRS232`BAUDRATEU230400 = 12
  • BrickletRS232`PARITYUNONE = 0
  • BrickletRS232`PARITYUODD = 1
  • BrickletRS232`PARITYUEVEN = 2
  • BrickletRS232`PARITYUFORCEDUPARITYU1 = 3
  • BrickletRS232`PARITYUFORCEDUPARITYU0 = 4
  • BrickletRS232`STOPBITSU1 = 1
  • BrickletRS232`STOPBITSU2 = 2
  • BrickletRS232`WORDLENGTHU5 = 5
  • BrickletRS232`WORDLENGTHU6 = 6
  • BrickletRS232`WORDLENGTHU7 = 7
  • BrickletRS232`WORDLENGTHU8 = 8
  • BrickletRS232`HARDWAREUFLOWCONTROLUOFF = 0
  • BrickletRS232`HARDWAREUFLOWCONTROLUON = 1
  • BrickletRS232`SOFTWAREUFLOWCONTROLUOFF = 0
  • BrickletRS232`SOFTWAREUFLOWCONTROLUON = 1
BrickletRS232@SetBreakCondition[breakTime] → Null
Parameters:
  • breakTime -- Integer

Sets a break condition (the TX output is forced to a logic 0 state). The parameter sets the hold-time of the break condition (in ms).

New in version 2.0.2 (Plugin).

Advanced Functions

BrickletRS232@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.

BrickletRS232@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.

BrickletRS232@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.

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:

  • BrickletRS232`FUNCTIONUENABLEUREADUCALLBACK = 3
  • BrickletRS232`FUNCTIONUDISABLEUREADUCALLBACK = 4
  • BrickletRS232`FUNCTIONUSETUCONFIGURATION = 6
  • BrickletRS232`FUNCTIONUSETUBREAKUCONDITION = 10
BrickletRS232@SetResponseExpectedAll[responseExpected] → Null
Parameters:
  • responseExpected -- True/False

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

BrickletRS232@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.

Callback Configuration Functions

BrickletRS232@EnableReadCallback[] → Null

Enables the ReadCallback callback.

By default the callback is disabled.

BrickletRS232@DisableReadCallback[] → Null

Disables the ReadCallback callback.

By default the callback is disabled.

BrickletRS232@IsReadCallbackEnabled[] → enabled
Returns:
  • enabled -- True/False

Returns true if the ReadCallback callback is enabled, false otherwise.

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:

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

AddEventHandler[rs232@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.

event BrickletRS232@ReadCallback[sender, {message1, message2, ..., message60}, length]
Parameters:
  • sender -- NETObject[BrickletRS232]
  • messagei -- Integer
  • length -- Integer

This callback is called if new data is available. The message has a maximum size of 60 characters. The actual length of the message is given in addition.

To enable this callback, use EnableReadCallback[].

event BrickletRS232@ErrorCallback[sender, error]
Parameters:
  • sender -- NETObject[BrickletRS232]
  • error -- Integer

This callback is called if an error occurs. Possible errors are overrun, parity or framing error.

The following constants are available for this function:

  • BrickletRS232`ERRORUOVERRUN = 1
  • BrickletRS232`ERRORUPARITY = 2
  • BrickletRS232`ERRORUFRAMING = 4

New in version 2.0.1 (Plugin).

Constants

BrickletRS232`DEVICEUIDENTIFIER

This constant is used to identify a RS232 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.

BrickletRS232`DEVICEDISPLAYNAME

This constant represents the human readable name of a RS232 Bricklet.