C# - Rotary Poti Bricklet

This is the description of the C# API bindings for the Rotary Poti Bricklet. General information and technical specifications for the Rotary 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)

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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 Rotary Poti Bricklet

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

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

        // Get current position
        short position = rp.GetPosition();
        Console.WriteLine("Position: " + position); // Range: -150 to 150

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

Callback

Download (ExampleCallback.cs)

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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 Rotary Poti Bricklet

    // Callback function for position callback
    static void PositionCB(BrickletRotaryPoti sender, short position)
    {
        Console.WriteLine("Position: " + position); // Range: -150 to 150
    }

    static void Main()
    {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletRotaryPoti rp = new BrickletRotaryPoti(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
        rp.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!
        rp.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

public class BrickletRotaryPoti(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid:

BrickletRotaryPoti rotaryPoti = new BrickletRotaryPoti("YOUR_DEVICE_UID", ipcon);

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

public short GetPosition()

Returns the position of the rotary potentiometer. The value is in degree and between -150° (turned left) and 150° (turned right).

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

Advanced Functions

public int GetAnalogValue()

Returns the value as read by a 12-bit analog-to-digital converter. The value is between 0 and 4095.

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().

public byte[] GetAPIVersion()

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.

public bool GetResponseExpected(byte functionId)

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.

public void SetResponseExpected(byte functionId, bool responseExpected)

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:

  • BrickletRotaryPoti.FUNCTION_SET_POSITION_CALLBACK_PERIOD = 3
  • BrickletRotaryPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_PERIOD = 5
  • BrickletRotaryPoti.FUNCTION_SET_POSITION_CALLBACK_THRESHOLD = 7
  • BrickletRotaryPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_THRESHOLD = 9
  • BrickletRotaryPoti.FUNCTION_SET_DEBOUNCE_PERIOD = 11
public void SetResponseExpectedAll(bool responseExpected)

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

public void GetIdentity(out string uid, out string connectedUid, out char position, out byte[] hardwareVersion, out byte[] firmwareVersion, out int deviceIdentifier)

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

public void SetPositionCallbackPeriod(long period)

Sets the period in ms 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.

The default value is 0.

public long GetPositionCallbackPeriod()

Returns the period as set by SetPositionCallbackPeriod().

public void SetAnalogValueCallbackPeriod(long period)

Sets the period in ms 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.

The default value is 0.

public long GetAnalogValueCallbackPeriod()

Returns the period as set by SetAnalogValueCallbackPeriod().

public void SetPositionCallbackThreshold(char option, short min, short max)

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

The following constants are available for this function:

  • BrickletRotaryPoti.THRESHOLD_OPTION_OFF = 'x'
  • BrickletRotaryPoti.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletRotaryPoti.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletRotaryPoti.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletRotaryPoti.THRESHOLD_OPTION_GREATER = '>'
public void GetPositionCallbackThreshold(out char option, out short min, out short max)

Returns the threshold as set by SetPositionCallbackThreshold().

The following constants are available for this function:

  • BrickletRotaryPoti.THRESHOLD_OPTION_OFF = 'x'
  • BrickletRotaryPoti.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletRotaryPoti.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletRotaryPoti.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletRotaryPoti.THRESHOLD_OPTION_GREATER = '>'
public void SetAnalogValueCallbackThreshold(char option, int min, int max)

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

The following constants are available for this function:

  • BrickletRotaryPoti.THRESHOLD_OPTION_OFF = 'x'
  • BrickletRotaryPoti.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletRotaryPoti.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletRotaryPoti.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletRotaryPoti.THRESHOLD_OPTION_GREATER = '>'
public void GetAnalogValueCallbackThreshold(out char option, out int min, out int max)

Returns the threshold as set by SetAnalogValueCallbackThreshold().

The following constants are available for this function:

  • BrickletRotaryPoti.THRESHOLD_OPTION_OFF = 'x'
  • BrickletRotaryPoti.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletRotaryPoti.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletRotaryPoti.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletRotaryPoti.THRESHOLD_OPTION_GREATER = '>'
public void SetDebouncePeriod(long debounce)

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

public long GetDebouncePeriod()

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

rotaryPoti.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.

public event PositionCallback(BrickletRotaryPoti sender, short position)

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

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

public event AnalogValueCallback(BrickletRotaryPoti sender, int value)

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

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

public event PositionReachedCallback(BrickletRotaryPoti sender, short position)

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

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

public event AnalogValueReachedCallback(BrickletRotaryPoti sender, int value)

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

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

Constants

public int DEVICE_IDENTIFIER

This constant is used to identify a Rotary Poti 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.

public string DEVICE_DISPLAY_NAME

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