Visual Basic .NET - DC Brick – Tinkerforge

- Getting Started
  - Primer
  - Tutorials
  - FAQ
- Hardware
  - Bricks
  - Bricklets
  - Master Extensions
  - Power Supplies
  - Accessories
  - Timeline
- Software
  - Brick Daemon (brickd)
  - Brick Viewer (brickv)
  - API Bindings
    - C/C++
    - C/C++ (iOS)
    - C#
    - C# (Windows Phone)
    - Delphi/Lazarus
    - Java
    - Java (Android)
    - JavaScript
    - LabVIEW
    - Mathematica
    - MATLAB/Octave
    - Perl
    - PHP
    - Python
    - Ruby
    - Shell
    - Visual Basic .NET
      - Requirements
      - Installation
      - Testing an Example
      - API Reference and Examples
        - IP Connection
        - Bricks
          - DC Brick
            - Examples
              - Configuration
              - Callback
            - API
              - Basic Functions
              - Advanced Functions
              - Callback Configuration Functions
              - Callbacks
              - Constants
          - IMU Brick
          - Master Brick
          - RED Brick
          - Servo Brick
          - Stepper Brick
        - Bricklets
  - Firmwares and Plugins
  - Device Identifier
  - Source Code and Bug Tracking
  - Programming Interface
- Starter Kits
  - Weather Station
  - Hardware Hacking
  - Server Room Monitoring
  - Blinkenlights
  - Internet of Things
  - Camera Slider
- Embedded Boards
  - Raspberry Pi
- Specifications
  - Technical Data
  - TCP/IP Protocol
  - Modbus Protocol
  - Wireshark Dissector

# Visual Basic .NET - DC Brick

This is the description of the Visual Basic .NET API bindings for the DC Brick. General information and technical specifications for the DC Brick are summarized in its hardware description.

An installation guide for the Visual Basic .NET API bindings is part of their general description.

## Examples

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

### Configuration

Download (ExampleConfiguration.vb)

     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

    Imports Tinkerforge

    Module ExampleConfiguration
        Const HOST As String = "localhost"
        Const PORT As Integer = 4223
        Const UID As String = "6eS9CJ" ' Change to your UID

        Sub Main()
            Dim ipcon As New IPConnection() ' Create IP connection
            Dim dc As New BrickDC(UID, ipcon) ' Create device object

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

            dc.SetPWMFrequency(10000) ' Use PWM frequency of 10kHz
            dc.SetDriveMode(1) ' Use 1 = Drive/Coast instead of 0 = Drive/Brake

            dc.Enable()
            dc.SetAcceleration(5000) ' Slow acceleration
            dc.SetVelocity(32767) ' Full speed forward

            System.Console.WriteLine("Press key to exit")
            System.Console.ReadLine()
            dc.Disable()
            ipcon.Disconnect()
        End Sub
    End Module

### Callback

Download (ExampleCallback.vb)

     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

    Imports Tinkerforge

    Module ExampleCallback
        Const HOST As String = "localhost"
        Const PORT As Integer = 4223
        Const UID As String = "6eS9CJ" ' Change to your UID

        ' Use velocity reached callback to swing back and forth between
        ' full speed forward and full speed backward
        Sub ReachedCB(ByVal sender As BrickDC, ByVal velocity As Short)
            If velocity = 32767 Then
                System.Console.WriteLine("Velocity: Full Speed forward, turning backward")
                sender.SetVelocity(-32767)
            Else If velocity = -32767 Then
                System.Console.WriteLine("Velocity: Full Speed backward, turning forward")
                sender.SetVelocity(32767)
            Else
                ' Can only happen if another program sets velocity
                System.Console.WriteLine("Error")
            End If
        End Sub

        Sub Main()
            Dim ipcon As New IPConnection() ' Create IP connection
            Dim dc As New BrickDC(UID, ipcon) ' Create device object

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

            ' Register "velocity reached callback" to ReachedCB
            ' ReachedCB will be called every time a velocity set with
            ' SetVelocity is reached
            AddHandler dc.VelocityReached, AddressOf ReachedCB

            dc.Enable()
            ' The acceleration has to be smaller or equal to the maximum acceleration
            ' of the DC motor, otherwise ReachedCB will be called too early
            dc.SetAcceleration(5000) ' Slow acceleration
            dc.SetVelocity(32767) ' Full speed forward

            System.Console.WriteLine("Press key to exit")
            System.Console.ReadLine()
            dc.Disable()
            ipcon.Disconnect()
        End Sub
    End Module

## API

Since Visual Basic .NET does not support multiple return values directly, we use the `ByRef` keyword to return multiple values from a function.

All functions and procedures listed below are thread-safe.

### Basic Functions

Class `BrickDC`(ByVal uid As String, ByVal ipcon As IPConnection)

  Creates an object with the unique device ID `uid`:

      Dim dc As New BrickDC("YOUR_DEVICE_UID", ipcon)

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

Sub `BrickDC.``SetVelocity`(ByVal velocity As Short)

  Sets the velocity of the motor. Whereas -32767 is full speed backward, 0 is stop and 32767 is full speed forward. Depending on the acceleration (see `SetAcceleration()`), the motor is not immediately brought to the velocity but smoothly accelerated.

  The velocity describes the duty cycle of the PWM with which the motor is controlled, e.g. a velocity of 3277 sets a PWM with a 10% duty cycle. You can not only control the duty cycle of the PWM but also the frequency, see `SetPWMFrequency()`.

  The default velocity is 0.

Function `BrickDC.``GetVelocity`() As Short

  Returns the velocity as set by `SetVelocity()`.

Function `BrickDC.``GetCurrentVelocity`() As Short

  Returns the current velocity of the motor. This value is different from `GetVelocity()` whenever the motor is currently accelerating to a goal set by `SetVelocity()`.

Sub `BrickDC.``SetAcceleration`(ByVal acceleration As Integer)

  Sets the acceleration of the motor. It is given in velocity/s. An acceleration of 10000 means, that every second the velocity is increased by 10000 (or about 30% duty cycle).

  For example: If the current velocity is 0 and you want to accelerate to a velocity of 16000 (about 50% duty cycle) in 10 seconds, you should set an acceleration of 1600.

  If acceleration is set to 0, there is no speed ramping, i.e. a new velocity is immediately given to the motor.

  The default acceleration is 10000.

Function `BrickDC.``GetAcceleration`() As Integer

  Returns the acceleration as set by `SetAcceleration()`.

Sub `BrickDC.``FullBrake`()

  Executes an active full brake.

  Warning

  This function is for emergency purposes, where an immediate brake is necessary. Depending on the current velocity and the strength of the motor, a full brake can be quite violent.

  Call `SetVelocity()` with 0 if you just want to stop the motor.

Sub `BrickDC.``Enable`()

  Enables the driver chip. The driver parameters can be configured (velocity, acceleration, etc) before it is enabled.

Sub `BrickDC.``Disable`()

  Disables the driver chip. The configurations are kept (velocity, acceleration, etc) but the motor is not driven until it is enabled again.

Function `BrickDC.``IsEnabled`() As Boolean

  Returns true if the driver chip is enabled, false otherwise.

### Advanced Functions

Sub `BrickDC.``SetPWMFrequency`(ByVal frequency As Integer)

  Sets the frequency (in Hz) of the PWM with which the motor is driven. The possible range of the frequency is 1-20000Hz. Often a high frequency is less noisy and the motor runs smoother. However, with a low frequency there are less switches and therefore fewer switching losses. Also with most motors lower frequencies enable higher torque.

  If you have no idea what all this means, just ignore this function and use the default frequency, it will very likely work fine.

  The default frequency is 15 kHz.

Function `BrickDC.``GetPWMFrequency`() As Integer

  Returns the PWM frequency (in Hz) as set by `SetPWMFrequency()`.

Function `BrickDC.``GetStackInputVoltage`() As Integer

  Returns the stack input voltage in mV. The stack input voltage is the voltage that is supplied via the stack, i.e. it is given by a Step-Down or Step-Up Power Supply.

Function `BrickDC.``GetExternalInputVoltage`() As Integer

  Returns the external input voltage in mV. The external input voltage is given via the black power input connector on the DC Brick.

  If there is an external input voltage and a stack input voltage, the motor will be driven by the external input voltage. If there is only a stack voltage present, the motor will be driven by this voltage.

  Warning

  This means, if you have a high stack voltage and a low external voltage, the motor will be driven with the low external voltage. If you then remove the external connection, it will immediately be driven by the high stack voltage.

Function `BrickDC.``GetCurrentConsumption`() As Integer

  Returns the current consumption of the motor in mA.

Sub `BrickDC.``SetDriveMode`(ByVal mode As Byte)

  Sets the drive mode. Possible modes are:

  - 0 = Drive/Brake
  - 1 = Drive/Coast

  These modes are different kinds of motor controls.

  In Drive/Brake mode, the motor is always either driving or braking. There is no freewheeling. Advantages are: A more linear correlation between PWM and velocity, more exact accelerations and the possibility to drive with slower velocities.

  In Drive/Coast mode, the motor is always either driving or freewheeling. Advantages are: Less current consumption and less demands on the motor and driver chip.

  The default value is 0 = Drive/Brake.

  The following constants are available for this function:

  - BrickDC.DRIVE_MODE_DRIVE_BRAKE = 0
  - BrickDC.DRIVE_MODE_DRIVE_COAST = 1

Function `BrickDC.``GetDriveMode`() As Byte

  Returns the drive mode, as set by `SetDriveMode()`.

  The following constants are available for this function:

  - BrickDC.DRIVE_MODE_DRIVE_BRAKE = 0
  - BrickDC.DRIVE_MODE_DRIVE_COAST = 1

Function `BrickDC.``GetAPIVersion`() As Byte()

  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.

Function `BrickDC.``GetResponseExpected`(ByVal functionId As Byte) As 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.

  See `SetResponseExpected()` for the list of function ID constants available for this function.

Sub `BrickDC.``SetResponseExpected`(ByVal functionId As Byte, ByVal responseExpected As 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 and callbacks it is always disabled.

  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:

  - BrickDC.FUNCTION_SET_VELOCITY = 1
  - BrickDC.FUNCTION_SET_ACCELERATION = 4
  - BrickDC.FUNCTION_SET_PWM_FREQUENCY = 6
  - BrickDC.FUNCTION_FULL_BRAKE = 8
  - BrickDC.FUNCTION_ENABLE = 12
  - BrickDC.FUNCTION_DISABLE = 13
  - BrickDC.FUNCTION_SET_MINIMUM_VOLTAGE = 15
  - BrickDC.FUNCTION_SET_DRIVE_MODE = 17
  - BrickDC.FUNCTION_SET_CURRENT_VELOCITY_PERIOD = 19
  - BrickDC.FUNCTION_ENABLE_STATUS_LED = 238
  - BrickDC.FUNCTION_DISABLE_STATUS_LED = 239
  - BrickDC.FUNCTION_RESET = 243

Sub `BrickDC.``SetResponseExpectedAll`(ByVal responseExpected As Boolean)

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

Sub `BrickDC.``EnableStatusLED`()

  Enables the status LED.

  The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.

  The default state is enabled.

  New in version 2.3.1 (Firmware).

Sub `BrickDC.``DisableStatusLED`()

  Disables the status LED.

  The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.

  The default state is enabled.

  New in version 2.3.1 (Firmware).

Function `BrickDC.``IsStatusLEDEnabled`() As Boolean

  Returns true if the status LED is enabled, false otherwise.

  New in version 2.3.1 (Firmware).

Sub `BrickDC.``GetProtocol1BrickletName`(ByVal port As Char, ByRef protocolVersion As Byte, ByRef firmwareVersion() As Byte, ByRef name As String)

  Returns the firmware and protocol version and the name of the Bricklet for a given port.

  This functions sole purpose is to allow automatic flashing of v1.x.y Bricklet plugins.

Function `BrickDC.``GetChipTemperature`() As Short

  Returns the temperature in °C/10 as measured inside the microcontroller. The value returned is not the ambient temperature!

  The temperature is only proportional to the real temperature and it has an accuracy of +-15%. Practically it is only useful as an indicator for temperature changes.

Sub `BrickDC.``Reset`()

  Calling this function will reset the Brick. Calling this function on a Brick inside of a stack will reset the whole stack.

  After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

Sub `BrickDC.``GetIdentity`(ByRef uid As String, ByRef connectedUid As String, ByRef position As Char, ByRef hardwareVersion() As Byte, ByRef firmwareVersion() As Byte, ByRef deviceIdentifier As Integer)

  Returns the UID, the UID where the Brick is connected to, the position, the hardware and firmware version as well as the device identifier.

  The position can be '0'-'8' (stack position).

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

### Callback Configuration Functions

Sub `BrickDC.``SetMinimumVoltage`(ByVal voltage As Integer)

  Sets the minimum voltage in mV, below which the `UnderVoltage` callback is triggered. The minimum possible value that works with the DC Brick is 6V. You can use this function to detect the discharge of a battery that is used to drive the motor. If you have a fixed power supply, you likely do not need this functionality.

  The default value is 6V.

Function `BrickDC.``GetMinimumVoltage`() As Integer

  Returns the minimum voltage as set by `SetMinimumVoltage()`

Sub `BrickDC.``SetCurrentVelocityPeriod`(ByVal period As Integer)

  Sets a period in ms with which the `CurrentVelocity` callback is triggered. A period of 0 turns the callback off.

  The default value is 0.

Function `BrickDC.``GetCurrentVelocityPeriod`() As Integer

  Returns the period as set by `SetCurrentVelocityPeriod()`.

### Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a procedure to an callback property of the device object:

>     Sub Callback(ByVal sender As BrickDC, ByVal value As Short)
>         Console.WriteLine("Value: {0}", value)
>     End Sub

>     AddHandler dc.Example, AddressOf Callback

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 `BrickDC.``UnderVoltage`(ByVal sender As BrickDC, ByVal voltage As Integer)

  This callback is triggered when the input voltage drops below the value set by `SetMinimumVoltage()`. The parameter is the current voltage given in mV.

Event `BrickDC.``EmergencyShutdown`(ByVal sender As BrickDC)

  This callback is triggered if either the current consumption is too high (above 5A) or the temperature of the driver chip is too high (above 175°C). These two possibilities are essentially the same, since the temperature will reach this threshold immediately if the motor consumes too much current. In case of a voltage below 3.3V (external or stack) this callback is triggered as well.

  If this callback is triggered, the driver chip gets disabled at the same time. That means, `Enable()` has to be called to drive the motor again.

  Note

  This callback only works in Drive/Brake mode (see `SetDriveMode()`). In Drive/Coast mode it is unfortunately impossible to reliably read the overcurrent/overtemperature signal from the driver chip.

Event `BrickDC.``VelocityReached`(ByVal sender As BrickDC, ByVal velocity As Short)

  This callback is triggered whenever a set velocity is reached. For example: If a velocity of 0 is present, acceleration is set to 5000 and velocity to 10000, `VelocityReached` will be triggered after about 2 seconds, when the set velocity is actually reached.

  Note

  Since we can't get any feedback from the DC motor, this only works if the acceleration (see `SetAcceleration()`) is set smaller or equal to the maximum acceleration of the motor. Otherwise the motor will lag behind the control value and the callback will be triggered too early.

Event `BrickDC.``CurrentVelocity`(ByVal sender As BrickDC, ByVal velocity As Short)

  This callback is triggered with the period that is set by `SetCurrentVelocityPeriod()`. The parameter is the current velocity used by the motor.

  `CurrentVelocity` is only triggered after the set period if there is a change in the velocity.

### Constants

Const `BrickDC.``DEVICE_IDENTIFIER`

  This constant is used to identify a DC Brick.

  The `GetIdentity()` function and the `EnumerateCallback` callback of the IP Connection have a `deviceIdentifier` parameter to specify the Brick's or Bricklet's type.

The content of this page is licensed under Creative Commons Attribution 3.0 Unported License.