Visual Basic .NET - RS232 Bricklet 2.0

This is the description of the Visual Basic .NET API bindings for the RS232 Bricklet 2.0. General information and technical specifications for the RS232 Bricklet 2.0 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).

Loopback

Download (ExampleLoopback.vb)

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Imports System
Imports Tinkerforge

' For this example connect the RX pin to the TX pin on the same Bricklet

Module ExampleLoopback
    Const HOST As String = "localhost"
    Const PORT As Integer = 4223
    Const UID As String = "XYZ" ' Change XYZ to the UID of your RS232 Bricklet 2.0

    ' Callback subroutine for read callback
    Sub ReadCB(ByVal sender As BrickletRS232V2, ByVal message As Char())
        ' Assume that the message consists of ASCII characters and convert it
        ' from an array of chars to a string
        Console.WriteLine("Message: ""{0}""", new String(message))
    End Sub

    Sub Main()
        Dim ipcon As New IPConnection() ' Create IP connection
        Dim rs232 As New BrickletRS232V2(UID, ipcon) ' Create device object

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

        ' Register read callback to subroutine ReadCB
        AddHandler rs232.ReadCallback, AddressOf ReadCB

        ' Enable read callback
        rs232.EnableReadCallback()

        ' Write "test" string
        rs232.Write("test".ToCharArray())

        Console.WriteLine("Press key to exit")
        Console.ReadLine()
        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 BrickletRS232V2(ByVal uid As String, ByVal ipcon As IPConnection)

Creates an object with the unique device ID uid:

Dim rs232V2 As New BrickletRS232V2("YOUR_DEVICE_UID", ipcon)

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

Function BrickletRS232V2.Write(ByVal message() As Char) As Integer

Writes characters to the RS232 interface. The characters can be binary data, ASCII or similar is not necessary.

The return value is the number of characters that were written.

See SetConfiguration() for configuration possibilities regarding baud rate, parity and so on.

Function BrickletRS232V2.Read(ByVal length As Integer) As Char()

Returns up to length characters from receive buffer.

Instead of polling with this function, you can also use callbacks. But note that this function will return available data only when the read callback is disabled. See EnableReadCallback() and ReadCallback callback.

Sub BrickletRS232V2.SetConfiguration(ByVal baudrate As Long, ByVal parity As Byte, ByVal stopbits As Byte, ByVal wordlength As Byte, ByVal flowcontrol As Byte)

Sets the configuration for the RS232 communication. Available options:

  • Baud rate between 100 and 2000000 baud.
  • Parity of none, odd or even.
  • Stop bits can be 1 or 2.
  • Word length of 5 to 8.
  • Flow control can be off, software or hardware.

The default is: 115200 baud, parity none, 1 stop bit, word length 8.

The following constants are available for this function:

  • BrickletRS232V2.PARITY_NONE = 0
  • BrickletRS232V2.PARITY_ODD = 1
  • BrickletRS232V2.PARITY_EVEN = 2
  • BrickletRS232V2.STOPBITS_1 = 1
  • BrickletRS232V2.STOPBITS_2 = 2
  • BrickletRS232V2.WORDLENGTH_5 = 5
  • BrickletRS232V2.WORDLENGTH_6 = 6
  • BrickletRS232V2.WORDLENGTH_7 = 7
  • BrickletRS232V2.WORDLENGTH_8 = 8
  • BrickletRS232V2.FLOWCONTROL_OFF = 0
  • BrickletRS232V2.FLOWCONTROL_SOFTWARE = 1
  • BrickletRS232V2.FLOWCONTROL_HARDWARE = 2
Sub BrickletRS232V2.GetConfiguration(ByRef baudrate As Long, ByRef parity As Byte, ByRef stopbits As Byte, ByRef wordlength As Byte, ByRef flowcontrol As Byte)

Returns the configuration as set by SetConfiguration().

The following constants are available for this function:

  • BrickletRS232V2.PARITY_NONE = 0
  • BrickletRS232V2.PARITY_ODD = 1
  • BrickletRS232V2.PARITY_EVEN = 2
  • BrickletRS232V2.STOPBITS_1 = 1
  • BrickletRS232V2.STOPBITS_2 = 2
  • BrickletRS232V2.WORDLENGTH_5 = 5
  • BrickletRS232V2.WORDLENGTH_6 = 6
  • BrickletRS232V2.WORDLENGTH_7 = 7
  • BrickletRS232V2.WORDLENGTH_8 = 8
  • BrickletRS232V2.FLOWCONTROL_OFF = 0
  • BrickletRS232V2.FLOWCONTROL_SOFTWARE = 1
  • BrickletRS232V2.FLOWCONTROL_HARDWARE = 2

Advanced Functions

Sub BrickletRS232V2.SetBufferConfig(ByVal sendBufferSize As Integer, ByVal receiveBufferSize As Integer)

Sets the send and receive buffer size in byte. In total the buffers have to be 10240 byte (10kb) in size, the minimum buffer size is 1024 byte (1kb) for each.

The current buffer content is lost if this function is called.

The send buffer holds data that is given by Write() and can not be written yet. The receive buffer holds data that is received through RS232 but could not yet be send to the user, either by Read() or through ReadCallback callback.

The default configuration is 5120 byte (5kb) per buffer.

Sub BrickletRS232V2.GetBufferConfig(ByRef sendBufferSize As Integer, ByRef receiveBufferSize As Integer)

Returns the buffer configuration as set by SetBufferConfig().

Sub BrickletRS232V2.GetBufferStatus(ByRef sendBufferUsed As Integer, ByRef receiveBufferUsed As Integer)

Returns the currently used bytes for the send and received buffer.

See SetBufferConfig() for buffer size configuration.

Sub BrickletRS232V2.GetErrorCount(ByRef errorCountOverrun As Long, ByRef errorCountParity As Long)

Returns the current number of overrun and parity errors.

Function BrickletRS232V2.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 BrickletRS232V2.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 BrickletRS232V2.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.

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:

  • BrickletRS232V2.FUNCTION_ENABLE_READ_CALLBACK = 3
  • BrickletRS232V2.FUNCTION_DISABLE_READ_CALLBACK = 4
  • BrickletRS232V2.FUNCTION_SET_CONFIGURATION = 6
  • BrickletRS232V2.FUNCTION_SET_BUFFER_CONFIG = 8
  • BrickletRS232V2.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletRS232V2.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletRS232V2.FUNCTION_RESET = 243
  • BrickletRS232V2.FUNCTION_WRITE_UID = 248
Sub BrickletRS232V2.SetResponseExpectedAll(ByVal responseExpected As Boolean)

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

Sub BrickletRS232V2.GetSPITFPErrorCount(ByRef errorCountAckChecksum As Long, ByRef errorCountMessageChecksum As Long, ByRef errorCountFrame As Long, ByRef errorCountOverflow As Long)

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

Function BrickletRS232V2.SetBootloaderMode(ByVal mode As Byte) As Byte

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

  • BrickletRS232V2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletRS232V2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BrickletRS232V2.BOOTLOADER_STATUS_OK = 0
  • BrickletRS232V2.BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletRS232V2.BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletRS232V2.BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletRS232V2.BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletRS232V2.BOOTLOADER_STATUS_CRC_MISMATCH = 5
Function BrickletRS232V2.GetBootloaderMode() As Byte

Returns the current bootloader mode, see SetBootloaderMode().

The following constants are available for this function:

  • BrickletRS232V2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletRS232V2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
Sub BrickletRS232V2.SetWriteFirmwarePointer(ByVal pointer As Long)

Sets the firmware pointer for WriteFirmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

Function BrickletRS232V2.WriteFirmware(ByVal data() As Byte) As Byte

Writes 64 Bytes of firmware at the position as written by SetWriteFirmwarePointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

Sub BrickletRS232V2.SetStatusLEDConfig(ByVal config As Byte)

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

  • BrickletRS232V2.STATUS_LED_CONFIG_OFF = 0
  • BrickletRS232V2.STATUS_LED_CONFIG_ON = 1
  • BrickletRS232V2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletRS232V2.STATUS_LED_CONFIG_SHOW_STATUS = 3
Function BrickletRS232V2.GetStatusLEDConfig() As Byte

Returns the configuration as set by SetStatusLEDConfig()

The following constants are available for this function:

  • BrickletRS232V2.STATUS_LED_CONFIG_OFF = 0
  • BrickletRS232V2.STATUS_LED_CONFIG_ON = 1
  • BrickletRS232V2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletRS232V2.STATUS_LED_CONFIG_SHOW_STATUS = 3
Function BrickletRS232V2.GetChipTemperature() As Short

Returns the temperature in °C 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 bad accuracy. Practically it is only useful as an indicator for temperature changes.

Sub BrickletRS232V2.Reset()

Calling this function will reset the Bricklet. All configurations will be lost.

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

Sub BrickletRS232V2.WriteUID(ByVal uid As Long)

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

Function BrickletRS232V2.ReadUID() As Long

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

Sub BrickletRS232V2.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 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

Sub BrickletRS232V2.EnableReadCallback()

Enables the ReadCallback callback.

By default the callback is disabled.

Sub BrickletRS232V2.DisableReadCallback()

Disables the ReadCallback callback.

By default the callback is disabled.

Function BrickletRS232V2.IsReadCallbackEnabled() As Boolean

Returns true if the ReadCallback callback is enabled, false otherwise.

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 MyCallback(ByVal sender As BrickletRS232V2, ByVal value As Short)
    Console.WriteLine("Value: {0}", value)
End Sub

AddHandler rs232V2.ExampleCallback, AddressOf MyCallback

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 BrickletRS232V2.ReadCallback(ByVal sender As BrickletRS232V2, ByVal message() As Char)

This callback is called if new data is available.

To enable this callback, use EnableReadCallback().

Event BrickletRS232V2.ErrorCountCallback(ByVal sender As BrickletRS232V2, ByVal errorCountOverrun As Long, ByVal errorCountParity As Long)

This callback is called if a new error occurs. It returns the current overrun and parity error count.

Constants

Const BrickletRS232V2.DEVICE_IDENTIFIER

This constant is used to identify a RS232 Bricklet 2.0.

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

Const BrickletRS232V2.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a RS232 Bricklet 2.0.