C# - Dual Button Bricklet

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

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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
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 Dual Button Bricklet

    // Callback function for state changed callback
    static void StateChangedCB(BrickletDualButton sender, byte buttonL, byte buttonR,
                               byte ledL, byte ledR)
    {
        if(buttonL == BrickletDualButton.BUTTON_STATE_PRESSED)
        {
            Console.WriteLine("Left Button: Pressed");
        }
        else if(buttonL == BrickletDualButton.BUTTON_STATE_RELEASED)
        {
            Console.WriteLine("Left Button: Released");
        }

        if(buttonR == BrickletDualButton.BUTTON_STATE_PRESSED)
        {
            Console.WriteLine("Right Button: Pressed");
        }
        else if(buttonR == BrickletDualButton.BUTTON_STATE_RELEASED)
        {
            Console.WriteLine("Right Button: Released");
        }

        Console.WriteLine("");
    }

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

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

        // Register state changed callback to function StateChangedCB
        db.StateChangedCallback += StateChangedCB;

        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 BrickletDualButton(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid:

BrickletDualButton dualButton = new BrickletDualButton("YOUR_DEVICE_UID", ipcon);

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

public void SetLEDState(byte ledL, byte ledR)

Sets the state of the LEDs. Possible states are:

  • 0 = AutoToggleOn: Enables auto toggle with initially enabled LED.
  • 1 = AutoToggleOff: Activates auto toggle with initially disabled LED.
  • 2 = On: Enables LED (auto toggle is disabled).
  • 3 = Off: Disables LED (auto toggle is disabled).

In auto toggle mode the LED is toggled automatically at each press of a button.

If you just want to set one of the LEDs and don't know the current state of the other LED, you can get the state with GetLEDState() or you can use SetSelectedLEDState().

The default value is (1, 1).

The following constants are available for this function:

  • BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
  • BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
  • BrickletDualButton.LED_STATE_ON = 2
  • BrickletDualButton.LED_STATE_OFF = 3
public void GetLEDState(out byte ledL, out byte ledR)

Returns the current state of the LEDs, as set by SetLEDState().

The following constants are available for this function:

  • BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
  • BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
  • BrickletDualButton.LED_STATE_ON = 2
  • BrickletDualButton.LED_STATE_OFF = 3
public void GetButtonState(out byte buttonL, out byte buttonR)

Returns the current state for both buttons. Possible states are:

  • 0 = pressed
  • 1 = released

The following constants are available for this function:

  • BrickletDualButton.BUTTON_STATE_PRESSED = 0
  • BrickletDualButton.BUTTON_STATE_RELEASED = 1

Advanced Functions

public void SetSelectedLEDState(byte led, byte state)

Sets the state of the selected LED (0 or 1).

The other LED remains untouched.

The following constants are available for this function:

  • BrickletDualButton.LED_LEFT = 0
  • BrickletDualButton.LED_RIGHT = 1
  • BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
  • BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
  • BrickletDualButton.LED_STATE_ON = 2
  • BrickletDualButton.LED_STATE_OFF = 3
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:

  • BrickletDualButton.FUNCTION_SET_LED_STATE = 1
  • BrickletDualButton.FUNCTION_SET_SELECTED_LED_STATE = 5
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.

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

dualButton.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 StateChangedCallback(BrickletDualButton sender, byte buttonL, byte buttonR, byte ledL, byte ledR)

This callback is called whenever a button is pressed.

Possible states for buttons are:

  • 0 = pressed
  • 1 = released

Possible states for LEDs are:

  • 0 = AutoToggleOn: Auto toggle enabled and LED on.
  • 1 = AutoToggleOff: Auto toggle enabled and LED off.
  • 2 = On: LED on (auto toggle is disabled).
  • 3 = Off: LED off (auto toggle is disabled).

The following constants are available for this function:

  • BrickletDualButton.BUTTON_STATE_PRESSED = 0
  • BrickletDualButton.BUTTON_STATE_RELEASED = 1
  • BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
  • BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
  • BrickletDualButton.LED_STATE_ON = 2
  • BrickletDualButton.LED_STATE_OFF = 3

Constants

public int DEVICE_IDENTIFIER

This constant is used to identify a Dual Button 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 Dual Button Bricklet.