C# - Linear Poti Bricklet

This is the description of the C# 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 C# API bindings is part of their general description.

Examples

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

Simple

Download (ExampleSimple.cs)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
using System;
using Tinkerforge;

class Example
{
    private static string HOST = "localhost";
    private static int PORT = 4223;
    private static string UID = "XYZ"; // Change XYZ to the UID of your Linear Poti Bricklet

    static void Main()
    {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletLinearPoti lp = new BrickletLinearPoti(UID, ipcon); // Create device object

        ipcon.Connect(HOST, PORT); // Connect to brickd
        // Don't use device before ipcon is connected

        // Get current position
        int position = lp.GetPosition();
        Console.WriteLine("Position: " + position); // Range: 0 to 100

        Console.WriteLine("Press enter to exit");
        Console.ReadLine();
        ipcon.Disconnect();
    }
}

Callback

Download (ExampleCallback.cs)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
using System;
using Tinkerforge;

class Example
{
    private static string HOST = "localhost";
    private static int PORT = 4223;
    private static string UID = "XYZ"; // Change XYZ to the UID of your Linear Poti Bricklet

    // Callback function for position callback
    static void PositionCB(BrickletLinearPoti sender, int position)
    {
        Console.WriteLine("Position: " + position); // Range: 0 to 100
    }

    static void Main()
    {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletLinearPoti lp = new BrickletLinearPoti(UID, ipcon); // Create device object

        ipcon.Connect(HOST, PORT); // Connect to brickd
        // Don't use device before ipcon is connected

        // Register position callback to function PositionCB
        lp.PositionCallback += PositionCB;

        // Set period for position callback to 0.05s (50ms)
        // Note: The position callback is only called every 0.05 seconds
        //       if the position has changed since the last call!
        lp.SetPositionCallbackPeriod(50);

        Console.WriteLine("Press enter to exit");
        Console.ReadLine();
        ipcon.Disconnect();
    }
}

API

Generally, every method of the C# 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 C# does not support multiple return values directly, we use the out keyword to return multiple values from a method.

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

All methods listed below are thread-safe.

Basic Functions

class BrickletLinearPoti(String uid, IPConnection ipcon)
Parameters:
  • uid – Type: String
  • ipcon – Type: IPConnection
Returns:
  • linearPoti – Type: BrickletLinearPoti

Creates an object with the unique device ID uid:

BrickletLinearPoti linearPoti = new BrickletLinearPoti("YOUR_DEVICE_UID", ipcon);

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

int BrickletLinearPoti.GetPosition()
Returns:
  • position – Type: int, 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

int BrickletLinearPoti.GetAnalogValue()
Returns:
  • value – Type: int, 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().

void BrickletLinearPoti.GetIdentity(out string uid, out string connectedUid, out char position, out byte[] hardwareVersion, out byte[] firmwareVersion, out int deviceIdentifier)
Output Parameters:
  • 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[], Length: 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[], Length: 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: int, 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

void BrickletLinearPoti.SetPositionCallbackPeriod(long period)
Parameters:
  • period – Type: long, 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.

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

Returns the period as set by SetPositionCallbackPeriod().

void BrickletLinearPoti.SetAnalogValueCallbackPeriod(long period)
Parameters:
  • period – Type: long, 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.

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

Returns the period as set by SetAnalogValueCallbackPeriod().

void BrickletLinearPoti.SetPositionCallbackThreshold(char option, int min, int max)
Parameters:
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: int, Range: [0 to 216 - 1], Default: 0
  • max – Type: int, 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 = '>'
void BrickletLinearPoti.GetPositionCallbackThreshold(out char option, out int min, out int max)
Output Parameters:
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: int, Range: [0 to 216 - 1], Default: 0
  • max – Type: int, 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 = '>'
void BrickletLinearPoti.SetAnalogValueCallbackThreshold(char option, int min, int max)
Parameters:
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: int, Range: [0 to 216 - 1], Default: 0
  • max – Type: int, 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 = '>'
void BrickletLinearPoti.GetAnalogValueCallbackThreshold(out char option, out int min, out int max)
Output Parameters:
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: int, Range: [0 to 216 - 1], Default: 0
  • max – Type: int, 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 = '>'
void BrickletLinearPoti.SetDebouncePeriod(long debounce)
Parameters:
  • debounce – Type: long, 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.

long BrickletLinearPoti.GetDebouncePeriod()
Returns:
  • debounce – Type: long, 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 appending your callback handler to the corresponding event:

void MyCallback(BrickletLinearPoti sender, int value)
{
    System.Console.WriteLine("Value: " + value);
}

linearPoti.ExampleCallback += MyCallback;

The available events 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(BrickletLinearPoti sender, int position)
Callback Parameters:
  • sender – Type: BrickletLinearPoti
  • position – Type: int, 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(BrickletLinearPoti sender, int value)
Callback Parameters:
  • sender – Type: BrickletLinearPoti
  • value – Type: int, 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(BrickletLinearPoti sender, int position)
Callback Parameters:
  • sender – Type: BrickletLinearPoti
  • position – Type: int, 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(BrickletLinearPoti sender, int value)
Callback Parameters:
  • sender – Type: BrickletLinearPoti
  • value – Type: int, 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.

byte[] BrickletLinearPoti.GetAPIVersion()
Output Parameters:
  • apiVersion – Type: byte[], Length: 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.

bool BrickletLinearPoti.GetResponseExpected(byte functionId)
Parameters:
  • functionId – Type: byte, Range: See constants
Returns:
  • responseExpected – Type: bool

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
void BrickletLinearPoti.SetResponseExpected(byte functionId, bool responseExpected)
Parameters:
  • functionId – Type: byte, Range: See constants
  • responseExpected – Type: bool

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
void BrickletLinearPoti.SetResponseExpectedAll(bool responseExpected)
Parameters:
  • responseExpected – Type: bool

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

Constants

int 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.

string BrickletLinearPoti.DEVICE_DISPLAY_NAME

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