LabVIEW - Linear Poti Bricklet

This is the description of the LabVIEW API bindings for the Linear Poti Bricklet. General information and technical specifications for the Linear Poti Bricklet are summarized in its hardware description.

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

API

Generally, every function of the LabVIEW bindings that outputs a value can report a Tinkerforge.TimeoutException. This error gets reported 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.

The namespace for all Brick/Bricklet bindings and the IPConnection is Tinkerforge.*.

Basic Functions

BrickletLinearPoti(uid, ipcon) → linearPoti
Input:
  • uid – Type: String
  • ipcon – Type: .NET Refnum (IPConnection)
Output:
  • linearPoti – Type: .NET Refnum (BrickletLinearPoti)

Creates an object with the unique device ID uid. This object can then be used after the IP Connection is connected (see examples above).

BrickletLinearPoti.GetPosition() → position
Output:
  • position – Type: Int32, Range: [0 to 100]

Returns the position of the linear potentiometer. The value is between 0 (slider down) and 100 (slider up).

If you want to get the position periodically, it is recommended to use the PositionCallback callback and set the period with SetPositionCallbackPeriod().

Advanced Functions

BrickletLinearPoti.GetAnalogValue() → value
Output:
  • value – Type: Int32, Range: [0 to 4095]

Returns the value as read by a 12-bit analog-to-digital converter.

Note

The value returned by GetPosition() is averaged over several samples to yield less noise, while GetAnalogValue() gives back raw unfiltered analog values. The only reason to use GetAnalogValue() is, if you need the full resolution of the analog-to-digital converter.

If you want the analog value periodically, it is recommended to use the AnalogValueCallback callback and set the period with SetAnalogValueCallbackPeriod().

BrickletLinearPoti.GetIdentity() → uid, connectedUid, position, hardwareVersion, firmwareVersion, deviceIdentifier
Output:
  • uid – Type: String, Length: up to 8
  • connectedUid – Type: String, Length: up to 8
  • position – Type: Char, Range: ["a" to "h", "i", "z"]
  • hardwareVersion – Type: Byte[3]
    • 0: major – Type: Byte, Range: [0 to 255]
    • 1: minor – Type: Byte, Range: [0 to 255]
    • 2: revision – Type: Byte, Range: [0 to 255]
  • firmwareVersion – Type: Byte[3]
    • 0: major – Type: Byte, Range: [0 to 255]
    • 1: minor – Type: Byte, Range: [0 to 255]
    • 2: revision – Type: Byte, Range: [0 to 255]
  • deviceIdentifier – Type: Int32, Range: [0 to 216 - 1]

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). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as position 'z'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

BrickletLinearPoti.SetPositionCallbackPeriod(period)
Input:
  • period – Type: Int64, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

The PositionCallback callback is only triggered if the position has changed since the last triggering.

BrickletLinearPoti.GetPositionCallbackPeriod() → period
Output:
  • period – Type: Int64, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by SetPositionCallbackPeriod().

BrickletLinearPoti.SetAnalogValueCallbackPeriod(period)
Input:
  • period – Type: Int64, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

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

The AnalogValueCallback callback is only triggered if the analog value has changed since the last triggering.

BrickletLinearPoti.GetAnalogValueCallbackPeriod() → period
Output:
  • period – Type: Int64, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by SetAnalogValueCallbackPeriod().

BrickletLinearPoti.SetPositionCallbackThreshold(option, min, max)
Input:
  • option – Type: Char, Range: See constants, Default: "x"
  • min – Type: Int32, Range: [0 to 216 - 1], Default: 0
  • max – Type: Int32, Range: [0 to 216 - 1], Default: 0

Sets the thresholds for the PositionReachedCallback callback.

The following options are possible:

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

The following constants are available for this function:

For option:

  • BrickletLinearPoti.THRESHOLD_OPTION_OFF = "x"
  • BrickletLinearPoti.THRESHOLD_OPTION_OUTSIDE = "o"
  • BrickletLinearPoti.THRESHOLD_OPTION_INSIDE = "i"
  • BrickletLinearPoti.THRESHOLD_OPTION_SMALLER = "<"
  • BrickletLinearPoti.THRESHOLD_OPTION_GREATER = ">"
BrickletLinearPoti.GetPositionCallbackThreshold() → option, min, max
Output:
  • option – Type: Char, Range: See constants, Default: "x"
  • min – Type: Int32, Range: [0 to 216 - 1], Default: 0
  • max – Type: Int32, Range: [0 to 216 - 1], Default: 0

Returns the threshold as set by SetPositionCallbackThreshold().

The following constants are available for this function:

For option:

  • BrickletLinearPoti.THRESHOLD_OPTION_OFF = "x"
  • BrickletLinearPoti.THRESHOLD_OPTION_OUTSIDE = "o"
  • BrickletLinearPoti.THRESHOLD_OPTION_INSIDE = "i"
  • BrickletLinearPoti.THRESHOLD_OPTION_SMALLER = "<"
  • BrickletLinearPoti.THRESHOLD_OPTION_GREATER = ">"
BrickletLinearPoti.SetAnalogValueCallbackThreshold(option, min, max)
Input:
  • option – Type: Char, Range: See constants, Default: "x"
  • min – Type: Int32, Range: [0 to 216 - 1], Default: 0
  • max – Type: Int32, Range: [0 to 216 - 1], Default: 0

Sets the thresholds for the AnalogValueReachedCallback callback.

The following options are possible:

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

The following constants are available for this function:

For option:

  • BrickletLinearPoti.THRESHOLD_OPTION_OFF = "x"
  • BrickletLinearPoti.THRESHOLD_OPTION_OUTSIDE = "o"
  • BrickletLinearPoti.THRESHOLD_OPTION_INSIDE = "i"
  • BrickletLinearPoti.THRESHOLD_OPTION_SMALLER = "<"
  • BrickletLinearPoti.THRESHOLD_OPTION_GREATER = ">"
BrickletLinearPoti.GetAnalogValueCallbackThreshold() → option, min, max
Output:
  • option – Type: Char, Range: See constants, Default: "x"
  • min – Type: Int32, Range: [0 to 216 - 1], Default: 0
  • max – Type: Int32, Range: [0 to 216 - 1], Default: 0

Returns the threshold as set by SetAnalogValueCallbackThreshold().

The following constants are available for this function:

For option:

  • BrickletLinearPoti.THRESHOLD_OPTION_OFF = "x"
  • BrickletLinearPoti.THRESHOLD_OPTION_OUTSIDE = "o"
  • BrickletLinearPoti.THRESHOLD_OPTION_INSIDE = "i"
  • BrickletLinearPoti.THRESHOLD_OPTION_SMALLER = "<"
  • BrickletLinearPoti.THRESHOLD_OPTION_GREATER = ">"
BrickletLinearPoti.SetDebouncePeriod(debounce)
Input:
  • debounce – Type: Int64, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Sets the period with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

BrickletLinearPoti.GetDebouncePeriod() → debounce
Output:
  • debounce – Type: Int64, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

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. 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 BrickletLinearPoti.PositionCallback → sender, position
Callback Output:
  • sender – Type: .NET Refnum (BrickletLinearPoti)
  • position – Type: Int32, Range: [0 to 100]

This callback is triggered periodically with the period that is set by SetPositionCallbackPeriod(). The parameter is the position of the linear potentiometer.

The PositionCallback callback is only triggered if the position has changed since the last triggering.

event BrickletLinearPoti.AnalogValueCallback → sender, value
Callback Output:
  • sender – Type: .NET Refnum (BrickletLinearPoti)
  • value – Type: Int32, Range: [0 to 4095]

This callback is triggered periodically with the period that is set by SetAnalogValueCallbackPeriod(). The parameter is the analog value of the Linear Potentiometer.

The AnalogValueCallback callback is only triggered if the position has changed since the last triggering.

event BrickletLinearPoti.PositionReachedCallback → sender, position
Callback Output:
  • sender – Type: .NET Refnum (BrickletLinearPoti)
  • position – Type: Int32, Range: [0 to 100]

This callback is triggered when the threshold as set by SetPositionCallbackThreshold() is reached. The parameter is the position of the linear potentiometer.

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

event BrickletLinearPoti.AnalogValueReachedCallback → sender, value
Callback Output:
  • sender – Type: .NET Refnum (BrickletLinearPoti)
  • value – Type: Int32, Range: [0 to 4095]

This callback is triggered when the threshold as set by SetAnalogValueCallbackThreshold() is reached. The parameter is the analog value of the linear potentiometer.

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

Virtual Functions

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.

BrickletLinearPoti.GetAPIVersion() → apiVersion
Output:
  • apiVersion – Type: Byte[3]
    • 0: major – Type: Byte, Range: [0 to 255]
    • 1: minor – Type: Byte, Range: [0 to 255]
    • 2: revision – Type: Byte, Range: [0 to 255]

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.

BrickletLinearPoti.GetResponseExpected(functionId) → responseExpected
Input:
  • functionId – Type: Byte, Range: See constants
Output:
  • responseExpected – Type: Boolean

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.

The following constants are available for this function:

For functionId:

  • BrickletLinearPoti.FUNCTION_SET_POSITION_CALLBACK_PERIOD = 3
  • BrickletLinearPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_PERIOD = 5
  • BrickletLinearPoti.FUNCTION_SET_POSITION_CALLBACK_THRESHOLD = 7
  • BrickletLinearPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_THRESHOLD = 9
  • BrickletLinearPoti.FUNCTION_SET_DEBOUNCE_PERIOD = 11
BrickletLinearPoti.SetResponseExpected(functionId, responseExpected)
Input:
  • functionId – Type: Byte, Range: See constants
  • responseExpected – Type: Boolean

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 constants are available for this function:

For functionId:

  • BrickletLinearPoti.FUNCTION_SET_POSITION_CALLBACK_PERIOD = 3
  • BrickletLinearPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_PERIOD = 5
  • BrickletLinearPoti.FUNCTION_SET_POSITION_CALLBACK_THRESHOLD = 7
  • BrickletLinearPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_THRESHOLD = 9
  • BrickletLinearPoti.FUNCTION_SET_DEBOUNCE_PERIOD = 11
BrickletLinearPoti.SetResponseExpectedAll(responseExpected)
Input:
  • responseExpected – Type: Boolean

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

Constants

BrickletLinearPoti.DEVICE_IDENTIFIER

This constant is used to identify a Linear Poti 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.

BrickletLinearPoti.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Linear Poti Bricklet.