Visual Basic .NET - Real-Time Clock Bricklet

This is the description of the Visual Basic .NET API bindings for the Real-Time Clock Bricklet. General information and technical specifications for the Real-Time Clock Bricklet 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).

Simple

Download (ExampleSimple.vb)

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Imports System
Imports Tinkerforge

Module ExampleSimple
    Const HOST As String = "localhost"
    Const PORT As Integer = 4223
    Const UID As String = "XYZ" ' Change XYZ to the UID of your Real-Time Clock Bricklet

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

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

        ' Get current date and time
        Dim year As Integer
        Dim month, day, hour, minute, second, centisecond, weekday As Byte

        rtc.GetDateTime(year, month, day, hour, minute, second, centisecond, weekday)

        Console.WriteLine("Year: " + year.ToString())
        Console.WriteLine("Month: " + month.ToString())
        Console.WriteLine("Day: " + day.ToString())
        Console.WriteLine("Hour: " + hour.ToString())
        Console.WriteLine("Minute: " + minute.ToString())
        Console.WriteLine("Second: " + second.ToString())
        Console.WriteLine("Centisecond: " + centisecond.ToString())
        Console.WriteLine("Weekday: " + weekday.ToString())

        ' Get current timestamp
        Dim timestamp As Long = rtc.GetTimestamp()
        Console.WriteLine("Timestamp: " + timestamp.ToString() + " ms")

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

Callback

Download (ExampleCallback.vb)

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Imports System
Imports Tinkerforge

Module ExampleCallback
    Const HOST As String = "localhost"
    Const PORT As Integer = 4223
    Const UID As String = "XYZ" ' Change XYZ to the UID of your Real-Time Clock Bricklet

    ' Callback subroutine for date and time callback
    Sub DateTimeCB(ByVal sender As BrickletRealTimeClock, ByVal year As Integer, _
                   ByVal month As Byte, ByVal day As Byte, ByVal hour As Byte, _
                   ByVal minute As Byte, ByVal second As Byte, _
                   ByVal centisecond As Byte, ByVal weekday As Byte, _
                   ByVal timestamp As Long)
        Console.WriteLine("Year: " + year.ToString())
        Console.WriteLine("Month: " + month.ToString())
        Console.WriteLine("Day: " + day.ToString())
        Console.WriteLine("Hour: " + hour.ToString())
        Console.WriteLine("Minute: " + minute.ToString())
        Console.WriteLine("Second: " + second.ToString())
        Console.WriteLine("Centisecond: " + centisecond.ToString())
        Console.WriteLine("Weekday: " + weekday.ToString())
        Console.WriteLine("Timestamp: " + timestamp.ToString())
        Console.WriteLine("")
    End Sub

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

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

        ' Register date and time callback to subroutine DateTimeCB
        AddHandler rtc.DateTimeCallback, AddressOf DateTimeCB

        ' Set period for date and time callback to 5s (5000ms)
        ' Note: The date and time callback is only called every 5 seconds
        '       if the date and time has changed since the last call!
        rtc.SetDateTimeCallbackPeriod(5000)

        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 BrickletRealTimeClock(ByVal uid As String, ByVal ipcon As IPConnection)

Creates an object with the unique device ID uid:

Dim realTimeClock As New BrickletRealTimeClock("YOUR_DEVICE_UID", ipcon)

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

Sub BrickletRealTimeClock.SetDateTime(ByVal year As Integer, ByVal month As Byte, ByVal day As Byte, ByVal hour As Byte, ByVal minute As Byte, ByVal second As Byte, ByVal centisecond As Byte, ByVal weekday As Byte)

Sets the current date (including weekday) and the current time with hundredths of a second resolution.

Possible value ranges:

  • Year: 2000 to 2099
  • Month: 1 to 12 (January to December)
  • Day: 1 to 31
  • Hour: 0 to 23
  • Minute: 0 to 59
  • Second: 0 to 59
  • Centisecond: 0 to 99
  • Weekday: 1 to 7 (Monday to Sunday)

If the backup battery is installed then the real-time clock keeps date and time even if the Bricklet is not powered by a Brick.

The real-time clock handles leap year and inserts the 29th of February accordingly. But leap seconds, time zones and daylight saving time are not handled.

The following constants are available for this function:

  • BrickletRealTimeClock.WEEKDAY_MONDAY = 1
  • BrickletRealTimeClock.WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClock.WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClock.WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClock.WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClock.WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClock.WEEKDAY_SUNDAY = 7
Sub BrickletRealTimeClock.GetDateTime(ByRef year As Integer, ByRef month As Byte, ByRef day As Byte, ByRef hour As Byte, ByRef minute As Byte, ByRef second As Byte, ByRef centisecond As Byte, ByRef weekday As Byte)

Returns the current date (including weekday) and the current time of the real-time clock with hundredths of a second resolution.

The following constants are available for this function:

  • BrickletRealTimeClock.WEEKDAY_MONDAY = 1
  • BrickletRealTimeClock.WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClock.WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClock.WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClock.WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClock.WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClock.WEEKDAY_SUNDAY = 7
Function BrickletRealTimeClock.GetTimestamp() As Long

Returns the current date and the time of the real-time clock converted to milliseconds. The timestamp has an effective resolution of hundredths of a second.

Advanced Functions

Sub BrickletRealTimeClock.SetOffset(ByVal offset As Short)

Sets the offset the real-time clock should compensate for in 2.17 ppm steps between -277.76 ppm (-128) and +275.59 ppm (127).

The real-time clock time can deviate from the actual time due to the frequency deviation of its 32.768 kHz crystal. Even without compensation (factory default) the resulting time deviation should be at most ±20 ppm (±52.6 seconds per month).

This deviation can be calculated by comparing the same duration measured by the real-time clock (rtc_duration) an accurate reference clock (ref_duration).

For best results the configured offset should be set to 0 ppm first and then a duration of at least 6 hours should be measured.

The new offset (new_offset) can be calculated from the currently configured offset (current_offset) and the measured durations as follow:

new_offset = current_offset - round(1000000 * (rtc_duration - ref_duration) / rtc_duration / 2.17)

If you want to calculate the offset, then we recommend using the calibration dialog in Brick Viewer, instead of doing it manually.

The offset is saved in the EEPROM of the Bricklet and only needs to be configured once.

Function BrickletRealTimeClock.GetOffset() As Short

Returns the offset as set by SetOffset().

Function BrickletRealTimeClock.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 BrickletRealTimeClock.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 BrickletRealTimeClock.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:

  • BrickletRealTimeClock.FUNCTION_SET_DATE_TIME = 1
  • BrickletRealTimeClock.FUNCTION_SET_OFFSET = 4
  • BrickletRealTimeClock.FUNCTION_SET_DATE_TIME_CALLBACK_PERIOD = 6
  • BrickletRealTimeClock.FUNCTION_SET_ALARM = 8
Sub BrickletRealTimeClock.SetResponseExpectedAll(ByVal responseExpected As Boolean)

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

Sub BrickletRealTimeClock.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 BrickletRealTimeClock.SetDateTimeCallbackPeriod(ByVal period As Long)

Sets the period in ms with which the DateTimeCallback callback is triggered periodically. A value of 0 turns the callback off.

The DateTimeCallback Callback is only triggered if the date or time changed since the last triggering.

The default value is 0.

New in version 2.0.1 (Plugin).

Function BrickletRealTimeClock.GetDateTimeCallbackPeriod() As Long

Returns the period as set by SetDateTimeCallbackPeriod().

New in version 2.0.1 (Plugin).

Sub BrickletRealTimeClock.SetAlarm(ByVal month As Short, ByVal day As Short, ByVal hour As Short, ByVal minute As Short, ByVal second As Short, ByVal weekday As Short, ByVal interval As Integer)

Configures a repeatable alarm. The AlarmCallback callback is triggered if the current date and time matches the configured alarm.

Setting a parameter to -1 means that it should be disabled and doesn't take part in the match. Setting all parameters to -1 disables the alarm completely.

For example, to make the alarm trigger every day at 7:30 AM it can be configured as (-1, -1, 7, 30, -1, -1, -1). The hour is set to match 7 and the minute is set to match 30. The alarm is triggered if all enabled parameters match.

The interval has a special role. It allows to make the alarm reconfigure itself. This is useful if you need a repeated alarm that cannot be expressed by matching the current date and time. For example, to make the alarm trigger every 23 seconds it can be configured as (-1, -1, -1, -1, -1, -1, 23). Internally the Bricklet will take the current date and time, add 23 seconds to it and set the result as its alarm. The first alarm will be triggered 23 seconds after the call. Because the interval is not -1, the Bricklet will do the same again internally, take the current date and time, add 23 seconds to it and set that as its alarm. This results in a repeated alarm that triggers every 23 seconds.

The interval can also be used in combination with the other parameters. For example, configuring the alarm as (-1, -1, 7, 30, -1, -1, 300) results in an alarm that triggers every day at 7:30 AM and is then repeated every 5 minutes.

The following constants are available for this function:

  • BrickletRealTimeClock.ALARM_MATCH_DISABLED = -1
  • BrickletRealTimeClock.ALARM_INTERVAL_DISABLED = -1

New in version 2.0.1 (Plugin).

Sub BrickletRealTimeClock.GetAlarm(ByRef month As Short, ByRef day As Short, ByRef hour As Short, ByRef minute As Short, ByRef second As Short, ByRef weekday As Short, ByRef interval As Integer)

Returns the alarm configuration as set by SetAlarm().

The following constants are available for this function:

  • BrickletRealTimeClock.ALARM_MATCH_DISABLED = -1
  • BrickletRealTimeClock.ALARM_INTERVAL_DISABLED = -1

New in version 2.0.1 (Plugin).

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

AddHandler realTimeClock.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 BrickletRealTimeClock.DateTimeCallback(ByVal sender As BrickletRealTimeClock, ByVal year As Integer, ByVal month As Byte, ByVal day As Byte, ByVal hour As Byte, ByVal minute As Byte, ByVal second As Byte, ByVal centisecond As Byte, ByVal weekday As Byte, ByVal timestamp As Long)

This callback is triggered periodically with the period that is set by SetDateTimeCallbackPeriod(). The parameters are the same as for GetDateTime() and GetTimestamp() combined.

The DateTimeCallback callback is only triggered if the date or time changed since the last triggering.

The following constants are available for this function:

  • BrickletRealTimeClock.WEEKDAY_MONDAY = 1
  • BrickletRealTimeClock.WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClock.WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClock.WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClock.WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClock.WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClock.WEEKDAY_SUNDAY = 7

New in version 2.0.1 (Plugin).

Event BrickletRealTimeClock.AlarmCallback(ByVal sender As BrickletRealTimeClock, ByVal year As Integer, ByVal month As Byte, ByVal day As Byte, ByVal hour As Byte, ByVal minute As Byte, ByVal second As Byte, ByVal centisecond As Byte, ByVal weekday As Byte, ByVal timestamp As Long)

This callback is triggered every time the current date and time matches the configured alarm (see SetAlarm()). The parameters are the same as for GetDateTime() and GetTimestamp() combined.

The following constants are available for this function:

  • BrickletRealTimeClock.WEEKDAY_MONDAY = 1
  • BrickletRealTimeClock.WEEKDAY_TUESDAY = 2
  • BrickletRealTimeClock.WEEKDAY_WEDNESDAY = 3
  • BrickletRealTimeClock.WEEKDAY_THURSDAY = 4
  • BrickletRealTimeClock.WEEKDAY_FRIDAY = 5
  • BrickletRealTimeClock.WEEKDAY_SATURDAY = 6
  • BrickletRealTimeClock.WEEKDAY_SUNDAY = 7

New in version 2.0.1 (Plugin).

Constants

Const BrickletRealTimeClock.DEVICE_IDENTIFIER

This constant is used to identify a Real-Time Clock 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.

Const BrickletRealTimeClock.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Real-Time Clock Bricklet.