C# - IP Connection

This is the description of the C# API bindings for the IP Connection. The IP Connection manages the communication between the API bindings and the Brick Daemon or a WIFI/Ethernet Extension. Before Bricks and Bricklets can be controlled using their API an IP Connection has to be created and its TCP/IP connection has to be established.

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).

Enumerate

Download (ExampleEnumerate.cs)

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using Tinkerforge;

class ExampleEnumerate
{
    private static string HOST = "localhost";
    private static int PORT = 4223;

    // Print incoming enumeration
    static void EnumerateCB(IPConnection sender,
                            string uid, string connectedUid, char position,
                            short[] hardwareVersion, short[] firmwareVersion,
                            int deviceIdentifier, short enumerationType)
    {
        System.Console.WriteLine("UID:               " + uid);
        System.Console.WriteLine("Enumeration Type:  " + enumerationType);

        if(enumerationType == IPConnection.ENUMERATION_TYPE_DISCONNECTED)
        {
            System.Console.WriteLine("");
            return;
        }

        System.Console.WriteLine("Connected UID:     " + connectedUid);
        System.Console.WriteLine("Position:          " + position);
        System.Console.WriteLine("Hardware Version:  " + hardwareVersion[0] + "." +
                                                         hardwareVersion[1] + "." +
                                                         hardwareVersion[2]);
        System.Console.WriteLine("Firmware Version:  " + firmwareVersion[0] + "." +
                                                         firmwareVersion[1] + "." +
                                                         firmwareVersion[2]);
        System.Console.WriteLine("Device Identifier: " + deviceIdentifier);
        System.Console.WriteLine("");
    }

    static void Main()
    {
        // Create connection and connect to brickd
        IPConnection ipcon = new IPConnection();
        ipcon.Connect(HOST, PORT);

        // Register Enumerate Callback
        ipcon.EnumerateCallback += EnumerateCB;

        // Trigger Enumerate
        ipcon.Enumerate();

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

Authenticate

Download (ExampleAuthenticate.cs)

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using Tinkerforge;

class ExampleAuthenticate
{
    private static string HOST = "localhost";
    private static int PORT = 4223;
    private static string SECRET = "My Authentication Secret!";

    // Authenticate each time the connection got (re-)established
    static void ConnectedCB(IPConnection sender, short connectReason)
    {
        switch(connectReason)
        {
            case IPConnection.CONNECT_REASON_REQUEST:
                System.Console.WriteLine("Connected by request");
                break;

            case IPConnection.CONNECT_REASON_AUTO_RECONNECT:
                System.Console.WriteLine("Auto-Reconnected");
                break;
        }

        // Authenticate first...
        try
        {
            sender.Authenticate(SECRET);
            System.Console.WriteLine("Authentication succeeded");
        }
        catch(TinkerforgeException)
        {
            System.Console.WriteLine("Could not authenticate");
            return;
        }

        // ...then trigger enumerate
        sender.Enumerate();
    }

    // Print incoming enumeration
    static void EnumerateCB(IPConnection sender,
                            string uid, string connectedUid, char position,
                            short[] hardwareVersion, short[] firmwareVersion,
                            int deviceIdentifier, short enumerationType)
    {
        System.Console.WriteLine("UID: " + uid + ", Enumeration Type: " + enumerationType);
    }

    static void Main()
    {
        // Create IP Connection
        IPConnection ipcon = new IPConnection();

        // Register Connected Callback
        ipcon.Connected += ConnectedCB;

        // Register Enumerate Callback
        ipcon.EnumerateCallback += EnumerateCB;

        // Connect to brickd
        ipcon.Connect(HOST, PORT);

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

API

The namespace for the IPConnection is Tinkerforge.*.

Basic Functions

public class IPConnection()

Creates an IP Connection object that can be used to enumerate the available devices. It is also required for the constructor of Bricks and Bricklets.

public void Connect(String host, int port)

Creates a TCP/IP connection to the given host and port. The host and port can refer to a Brick Daemon or to a WIFI/Ethernet Extension.

Devices can only be controlled when the connection was established successfully.

Blocks until the connection is established and throws an exception if there is no Brick Daemon or WIFI/Ethernet Extension listening at the given host and port.

public void Disconnect()

Disconnects the TCP/IP connection from the Brick Daemon or the WIFI/Ethernet Extension.

public void Authenticate(string secret)

Performs an authentication handshake with the connected Brick Daemon or WIFI/Ethernet Extension. If the handshake succeeds the connection switches from non-authenticated to authenticated state and communication can continue as normal. If the handshake fails then the connection gets closed. Authentication can fail if the wrong secret was used or if authentication is not enabled at all on the Brick Daemon or the WIFI/Ethernet Extension.

See the authentication tutorial for more information.

New in version 2.1.0.

public byte GetConnectionState()

Can return the following states:

  • IPConnection.CONNECTION_STATE_DISCONNECTED (0): No connection is established.
  • IPConnection.CONNECTION_STATE_CONNECTED (1): A connection to the Brick Daemon or the WIFI/Ethernet Extension is established.
  • IPConnection.CONNECTION_STATE_PENDING (2): IP Connection is currently trying to connect.
public void SetAutoReconnect(bool autoReconnect)

Enables or disables auto-reconnect. If auto-reconnect is enabled, the IP Connection will try to reconnect to the previously given host and port, if the currently existing connection is lost. Therefore, auto-reconnect only does something after a successful Connect() call.

Default value is true.

public bool GetAutoReconnect()

Returns true if auto-reconnect is enabled, false otherwise.

public void SetTimeout(int timeout)

Sets the timeout in milliseconds for getters and for setters for which the response expected flag is activated.

Default timeout is 2500.

public int GetTimeout()

Returns the timeout as set by SetTimeout().

public void Enumerate()

Broadcasts an enumerate request. All devices will respond with an enumerate callback.

public void Wait()

Stops the current thread until Unwait() is called.

This is useful if you rely solely on callbacks for events, if you want to wait for a specific callback or if the IP Connection was created in a thread.

Wait and Unwait act in the same way as Acquire and Release of a semaphore.

public void Unwait()

Unwaits the thread previously stopped by Wait()

Wait and Unwait act in the same way as Acquire and Release of a semaphore.

Callbacks

Callbacks can be registered to be notified about events. The registration is done by appending your callback handler to the corresponding event:

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

ipcon.ExampleCallback += MyCallback;

The available events are described below.

public event EnumerateCallback(IPConnection sender, string uid, string connectedUid, char position, short[] hardwareVersion, short[] firmwareVersion, int deviceIdentifier, short enumerationType)

The event receives seven parameters:

  • uid: The UID of the device.
  • connectedUid: UID where the device is connected to. For a Bricklet this will be a UID of the Brick where it is connected to. For a Brick it will be the UID of the bottom Master Brick in the stack. For the bottom Master Brick in a stack this will be "0". With this information it is possible to reconstruct the complete network topology.
  • position: For Bricks: '0' - '8' (position in stack). For Bricklets: 'a' - 'd' (position on Brick).
  • hardwareVersion: Major, minor and release number for hardware version.
  • firmwareVersion: Major, minor and release number for firmware version.
  • deviceIdentifier: A number that represents the device.
  • enumerationType: Type of enumeration.

Possible enumeration types are:

  • IPConnection.ENUMERATION_TYPE_AVAILABLE (0): Device is available (enumeration triggered by user: Enumerate()). This enumeration type can occur multiple times for the same device.
  • IPConnection.ENUMERATION_TYPE_CONNECTED (1): Device is newly connected (automatically send by Brick after establishing a communication connection). This indicates that the device has potentially lost its previous configuration and needs to be reconfigured.
  • IPConnection.ENUMERATION_TYPE_DISCONNECTED (2): Device is disconnected (only possible for USB connection). In this case only uid and enumerationType are valid.

It should be possible to implement plug-and-play functionality with this (as is done in Brick Viewer).

The device identifier numbers can be found here. There are also constants for these numbers named following this pattern:

<device-class>.DEVICE_IDENTIFIER

For example: BrickMaster.DEVICE_IDENTIFIER or BrickletAmbientLight.DEVICE_IDENTIFIER.

public event ConnectedCallback(IPConnection sender, short connectReason)

This event is triggered whenever the IP Connection got connected to a Brick Daemon or to a WIFI/Ethernet Extension, possible reasons are:

  • IPConnection.CONNECT_REASON_REQUEST (0): Connection established after request from user.
  • IPConnection.CONNECT_REASON_AUTO_RECONNECT (1): Connection after auto-reconnect.
public event DisconnectedCallback(IPConnection sender, short disconnectReason)

This event is triggered whenever the IP Connection got disconnected from a Brick Daemon or to a WIFI/Ethernet Extension, possible reasons are:

  • IPConnection.DISCONNECT_REASON_REQUEST (0): Disconnect was requested by user.
  • IPConnection.DISCONNECT_REASON_ERROR (1): Disconnect because of an unresolvable error.
  • IPConnection.DISCONNECT_REASON_SHUTDOWN (2): Disconnect initiated by Brick Daemon or WIFI/Ethernet Extension.