Mathematica - Barometer Bricklet

This is the description of the Mathematica API bindings for the Barometer Bricklet. General information and technical specifications for the Barometer 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="XYZ"(*Change XYZ to the UID of your Barometer Bricklet*)

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

(*Get current air pressure*)
Print["Air Pressure: "<>ToString[N[Quantity[b@GetAirPressure[],"mbar/1000"]]]]

(*Get current altitude*)
Print["Altitude: "<>ToString[N[Quantity[b@GetAltitude[],"m/100"]]]]

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

Callback

Download (ExampleCallback.nb)

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

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

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

(*Callback function for air pressure callback*)
AirPressureCB[sender_,airPressure_]:=
 Print["Air Pressure: "<>ToString[N[Quantity[airPressure,"mbar/1000"]]]]
AddEventHandler[b@AirPressureCallback,AirPressureCB]

(*Set period for air pressure callback to 1s (1000ms)*)
(*Note: The air pressure callback is only called every second*)
(*if the air pressure has changed since the last call!*)
b@SetAirPressureCallbackPeriod[1000]

Input["Click OK to exit"]

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

Threshold

Download (ExampleThreshold.nb)

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

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

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

(*Get threshold callbacks with a debounce time of 10 seconds (10000ms)*)
b@SetDebouncePeriod[10000]

(*Callback function for air pressure reached callback*)
AirPressureReachedCB[sender_,airPressure_]:=
 Module[{},
  Print["Air Pressure: "<>ToString[N[Quantity[airPressure,"mbar/1000"]]]];
  Print["Enjoy the potentially good weather!"]
 ]

AddEventHandler[b@AirPressureReachedCallback,AirPressureReachedCB]

(*Configure threshold for air pressure "greater than 1025 mbar"*)
option=Tinkerforge`BrickletBarometer`THRESHOLDUOPTIONUGREATER
b@SetAirPressureCallbackThreshold[option,1025*1000,0]

Input["Click OK to exit"]

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

BrickletBarometer[uid, ipcon] → barometer
Parameters:
  • uid -- String
  • ipcon -- NETObject[IPConnection]
Returns:
  • barometer -- NETObject[BrickletBarometer]

Creates an object with the unique device ID uid:

barometer=NETNew["Tinkerforge.BrickletBarometer","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.

BrickletBarometer@GetAirPressure[] → airPressure
Returns:
  • airPressure -- Integer

Returns the air pressure of the air pressure sensor. The value has a range of 10000 to 1200000 and is given in mbar/1000, i.e. a value of 1001092 means that an air pressure of 1001.092 mbar is measured.

If you want to get the air pressure periodically, it is recommended to use the AirPressureCallback callback and set the period with SetAirPressureCallbackPeriod[].

BrickletBarometer@GetAltitude[] → altitude
Returns:
  • altitude -- Integer

Returns the relative altitude of the air pressure sensor. The value is given in cm and is calculated based on the difference between the current air pressure and the reference air pressure that can be set with SetReferenceAirPressure[].

If you want to get the altitude periodically, it is recommended to use the AltitudeCallback callback and set the period with SetAltitudeCallbackPeriod[].

BrickletBarometer@SetReferenceAirPressure[airPressure] → Null
Parameters:
  • airPressure -- Integer

Sets the reference air pressure in mbar/1000 for the altitude calculation. Valid values are between 10000 and 1200000. Setting the reference to the current air pressure results in a calculated altitude of 0cm. Passing 0 is a shortcut for passing the current air pressure as reference.

Well known reference values are the Q codes QNH and QFE used in aviation.

The default value is 1013.25mbar.

BrickletBarometer@GetReferenceAirPressure[] → airPressure
Returns:
  • airPressure -- Integer

Returns the reference air pressure as set by SetReferenceAirPressure[].

Advanced Functions

BrickletBarometer@GetChipTemperature[] → temperature
Returns:
  • temperature -- Integer

Returns the temperature of the air pressure sensor. The value has a range of -4000 to 8500 and is given in °C/100, i.e. a value of 2007 means that a temperature of 20.07 °C is measured.

This temperature is used internally for temperature compensation of the air pressure measurement. It is not as accurate as the temperature measured by the Temperature Bricklet or the Temperature IR Bricklet.

BrickletBarometer@SetAveraging[movingAveragePressure, averagePressure, averageTemperature] → Null
Parameters:
  • movingAveragePressure -- Integer
  • averagePressure -- Integer
  • averageTemperature -- Integer

Sets the different averaging parameters. It is possible to set the length of a normal averaging for the temperature and pressure, as well as an additional length of a moving average for the pressure. The moving average is calculated from the normal averages. There is no moving average for the temperature.

The maximum length for the pressure average is 10, for the temperature average is 255 and for the moving average is 25.

Setting the all three parameters to 0 will turn the averaging completely off. If the averaging is off, there is lots of noise on the data, but the data is without delay. Thus we recommend to turn the averaging off if the Barometer Bricklet data is to be used for sensor fusion with other sensors.

The default values are 10 for the normal averages and 25 for the moving average.

New in version 2.0.1 (Plugin).

BrickletBarometer@GetAveraging[out movingAveragePressure, out averagePressure, out averageTemperature] → Null
Parameters:
  • movingAveragePressure -- Integer
  • averagePressure -- Integer
  • averageTemperature -- Integer

Returns the averaging configuration as set by SetAveraging[].

New in version 2.0.1 (Plugin).

BrickletBarometer@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.

BrickletBarometer@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.

BrickletBarometer@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:

  • BrickletBarometer`FUNCTIONUSETUAIRUPRESSUREUCALLBACKUPERIOD = 3
  • BrickletBarometer`FUNCTIONUSETUALTITUDEUCALLBACKUPERIOD = 5
  • BrickletBarometer`FUNCTIONUSETUAIRUPRESSUREUCALLBACKUTHRESHOLD = 7
  • BrickletBarometer`FUNCTIONUSETUALTITUDEUCALLBACKUTHRESHOLD = 9
  • BrickletBarometer`FUNCTIONUSETUDEBOUNCEUPERIOD = 11
  • BrickletBarometer`FUNCTIONUSETUREFERENCEUAIRUPRESSURE = 13
  • BrickletBarometer`FUNCTIONUSETUAVERAGING = 20
BrickletBarometer@SetResponseExpectedAll[responseExpected] → Null
Parameters:
  • responseExpected -- True/False

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

BrickletBarometer@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

BrickletBarometer@SetAirPressureCallbackPeriod[period] → Null
Parameters:
  • period -- Integer

Sets the period in ms with which the AirPressureCallback callback is triggered periodically. A value of 0 turns the callback off.

The AirPressureCallback callback is only triggered if the air pressure has changed since the last triggering.

The default value is 0.

BrickletBarometer@GetAirPressureCallbackPeriod[] → period
Returns:
  • period -- Integer

Returns the period as set by SetAirPressureCallbackPeriod[].

BrickletBarometer@SetAltitudeCallbackPeriod[period] → Null
Parameters:
  • period -- Integer

Sets the period in ms with which the AltitudeCallback callback is triggered periodically. A value of 0 turns the callback off.

The AltitudeCallback callback is only triggered if the altitude has changed since the last triggering.

The default value is 0.

BrickletBarometer@GetAltitudeCallbackPeriod[] → period
Returns:
  • period -- Integer

Returns the period as set by SetAltitudeCallbackPeriod[].

BrickletBarometer@SetAirPressureCallbackThreshold[option, min, max] → Null
Parameters:
  • option -- Integer
  • min -- Integer
  • max -- Integer

Sets the thresholds for the AirPressureReachedCallback callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the air pressure is outside the min and max values
'i' Callback is triggered when the air pressure is inside the min and max values
'<' Callback is triggered when the air pressure is smaller than the min value (max is ignored)
'>' Callback is triggered when the air pressure is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following constants are available for this function:

  • BrickletBarometer`THRESHOLDUOPTIONUOFF = ToCharacterCode["x"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUOUTSIDE = ToCharacterCode["o"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUINSIDE = ToCharacterCode["i"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUSMALLER = ToCharacterCode["<"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUGREATER = ToCharacterCode[">"][[0]]
BrickletBarometer@GetAirPressureCallbackThreshold[out option, out min, out max] → Null
Parameters:
  • option -- Integer
  • min -- Integer
  • max -- Integer

Returns the threshold as set by SetAirPressureCallbackThreshold[].

The following constants are available for this function:

  • BrickletBarometer`THRESHOLDUOPTIONUOFF = ToCharacterCode["x"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUOUTSIDE = ToCharacterCode["o"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUINSIDE = ToCharacterCode["i"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUSMALLER = ToCharacterCode["<"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUGREATER = ToCharacterCode[">"][[0]]
BrickletBarometer@SetAltitudeCallbackThreshold[option, min, max] → Null
Parameters:
  • option -- Integer
  • min -- Integer
  • max -- Integer

Sets the thresholds for the AltitudeReachedCallback callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the altitude is outside the min and max values
'i' Callback is triggered when the altitude is inside the min and max values
'<' Callback is triggered when the altitude is smaller than the min value (max is ignored)
'>' Callback is triggered when the altitude is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following constants are available for this function:

  • BrickletBarometer`THRESHOLDUOPTIONUOFF = ToCharacterCode["x"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUOUTSIDE = ToCharacterCode["o"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUINSIDE = ToCharacterCode["i"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUSMALLER = ToCharacterCode["<"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUGREATER = ToCharacterCode[">"][[0]]
BrickletBarometer@GetAltitudeCallbackThreshold[out option, out min, out max] → Null
Parameters:
  • option -- Integer
  • min -- Integer
  • max -- Integer

Returns the threshold as set by SetAltitudeCallbackThreshold[].

The following constants are available for this function:

  • BrickletBarometer`THRESHOLDUOPTIONUOFF = ToCharacterCode["x"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUOUTSIDE = ToCharacterCode["o"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUINSIDE = ToCharacterCode["i"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUSMALLER = ToCharacterCode["<"][[0]]
  • BrickletBarometer`THRESHOLDUOPTIONUGREATER = ToCharacterCode[">"][[0]]
BrickletBarometer@SetDebouncePeriod[debounce] → Null
Parameters:
  • debounce -- Integer

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

BrickletBarometer@GetDebouncePeriod[] → debounce
Returns:
  • debounce -- Integer

Returns the debounce period as set by SetDebouncePeriod[].

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[barometer@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 BrickletBarometer@AirPressureCallback[sender, airPressure]
Parameters:
  • sender -- NETObject[BrickletBarometer]
  • airPressure -- Integer

This callback is triggered periodically with the period that is set by SetAirPressureCallbackPeriod[]. The parameter is the air pressure of the air pressure sensor.

The AirPressureCallback callback is only triggered if the air pressure has changed since the last triggering.

event BrickletBarometer@AltitudeCallback[sender, altitude]
Parameters:
  • sender -- NETObject[BrickletBarometer]
  • altitude -- Integer

This callback is triggered periodically with the period that is set by SetAltitudeCallbackPeriod[]. The parameter is the altitude of the air pressure sensor.

The AltitudeCallback callback is only triggered if the altitude has changed since the last triggering.

event BrickletBarometer@AirPressureReachedCallback[sender, airPressure]
Parameters:
  • sender -- NETObject[BrickletBarometer]
  • airPressure -- Integer

This callback is triggered when the threshold as set by SetAirPressureCallbackThreshold[] is reached. The parameter is the air pressure of the air pressure sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by SetDebouncePeriod[].

event BrickletBarometer@AltitudeReachedCallback[sender, altitude]
Parameters:
  • sender -- NETObject[BrickletBarometer]
  • altitude -- Integer

This callback is triggered when the threshold as set by SetAltitudeCallbackThreshold[] is reached. The parameter is the altitude of the air pressure sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by SetDebouncePeriod[].

Constants

BrickletBarometer`DEVICEUIDENTIFIER

This constant is used to identify a Barometer 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.

BrickletBarometer`DEVICEDISPLAYNAME

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