Delphi/Lazarus - DMX Bricklet

This is the description of the Delphi/Lazarus API bindings for the DMX Bricklet. General information and technical specifications for the DMX Bricklet are summarized in its hardware description.

An installation guide for the Delphi/Lazarus API bindings is part of their general description.

Examples

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

Simple

Download (ExampleSimple.pas)

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program ExampleSimple;

{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}

uses
  SysUtils, IPConnection, BrickletDMX;

type
  TExample = class
  private
    ipcon: TIPConnection;
    dmx: TBrickletDMX;
  public
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your DMX Bricklet }

var
  e: TExample;

procedure TExample.Execute;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  dmx := TBrickletDMX.Create(UID, ipcon);

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

  { Configure Bricklet as DMX master }
  dmx.SetDMXMode(BRICKLET_DMX_DMX_MODE_MASTER);

  { Write DMX frame with 3 channels }
  dmx.WriteFrame([255, 128, 0]);

  WriteLn('Press key to exit');
  ReadLn;
  ipcon.Destroy; { Calls ipcon.Disconnect internally }
end;

begin
  e := TExample.Create;
  e.Execute;
  e.Destroy;
end.

API

Since Delphi does not support multiple return values directly, we use the out keyword to return multiple values from a function.

All functions and procedures listed below are thread-safe.

Basic Functions

constructor TBrickletDMX.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

dmx := TBrickletDMX.Create('YOUR_DEVICE_UID', ipcon);

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

procedure TBrickletDMX.SetDMXMode(const dmxMode: byte)

Sets the DMX mode to either master or slave.

Calling this function sets frame number to 0.

The default value is 0 (master).

The following constants are available for this function:

  • BRICKLET_DMX_DMX_MODE_MASTER = 0
  • BRICKLET_DMX_DMX_MODE_SLAVE = 1
function TBrickletDMX.GetDMXMode: byte

Returns the DMX mode, as set by SetDMXMode.

The following constants are available for this function:

  • BRICKLET_DMX_DMX_MODE_MASTER = 0
  • BRICKLET_DMX_DMX_MODE_SLAVE = 1
procedure TBrickletDMX.WriteFrameLowLevel(const frameLength: word; const frameChunkOffset: word; const frameChunkData: array [0..59] of byte)

Writes a DMX frame. The maximum frame size is 512 byte. Each byte represents one channel.

The next frame can be written after the OnFrameStarted callback was called. The frame is double buffered, so a new frame can be written as soon as the writing of the prior frame starts.

The data will be transfered when the next frame duration ends, see SetFrameDuration.

Generic approach:

  • Set the frame duration to a value that represents the number of frames per second you want to achieve.
  • Set channels for first frame.
  • Wait for the OnFrameStarted callback.
  • Set channels for next frame.
  • Wait for the OnFrameStarted callback.
  • and so on.

This approach ensures that you can set new DMX data with a fixed frame rate.

This function can only be called in master mode.

procedure TBrickletDMX.ReadFrameLowLevel(out frameLength: word; out frameChunkOffset: word; out frameChunkData: array [0..55] of byte; out frameNumber: longword)

Returns the last frame that was written by the DMX master. The size of the array is equivalent to the number of channels in the frame. Each byte represents one channel.

The next frame is available after the OnFrameAvailable callback was called.

Generic approach:

  • Call ReadFrame to get first frame.
  • Wait for the OnFrameAvailable callback.
  • Call ReadFrame to get second frame.
  • Wait for the OnFrameAvailable callback.
  • and so on.

Instead of polling this function you can also use the OnFrame callback. You can enable it with SetFrameCallbackConfig.

The frame number starts at 0 and it is increased by one with each received frame.

This function can only be called in slave mode.

procedure TBrickletDMX.SetFrameDuration(const frameDuration: word)

Sets the duration of a frame in ms.

Example: If you want to achieve 20 frames per second, you should set the frame duration to 50ms (50ms * 20 = 1 second).

If you always want to send a frame as fast as possible you can set this value to 0.

This setting is only used in master mode.

Default value: 100ms (10 frames per second).

function TBrickletDMX.GetFrameDuration: word

Returns the frame duration as set by SetFrameDuration.

Advanced Functions

procedure TBrickletDMX.GetFrameErrorCount(out overrunErrorCount: longword; out framingErrorCount: longword)

Returns the current number of overrun and framing errors.

procedure TBrickletDMX.SetCommunicationLEDConfig(const config: byte)

Sets the communication LED configuration. By default the LED shows communication traffic, 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 off.

The following constants are available for this function:

  • BRICKLET_DMX_COMMUNICATION_LED_CONFIG_OFF = 0
  • BRICKLET_DMX_COMMUNICATION_LED_CONFIG_ON = 1
  • BRICKLET_DMX_COMMUNICATION_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_DMX_COMMUNICATION_LED_CONFIG_SHOW_COMMUNICATION = 3
function TBrickletDMX.GetCommunicationLEDConfig: byte

Returns the configuration as set by SetCommunicationLEDConfig

The following constants are available for this function:

  • BRICKLET_DMX_COMMUNICATION_LED_CONFIG_OFF = 0
  • BRICKLET_DMX_COMMUNICATION_LED_CONFIG_ON = 1
  • BRICKLET_DMX_COMMUNICATION_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_DMX_COMMUNICATION_LED_CONFIG_SHOW_COMMUNICATION = 3
procedure TBrickletDMX.SetErrorLEDConfig(const config: byte)

Sets the error LED configuration.

By default the error LED turns on if there is any error (see OnFrameErrorCount callback). If you call this function with the Show-Error option again, the LED will turn off until the next error occurs.

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

If the Bricklet is in bootloader mode, the LED is off.

The following constants are available for this function:

  • BRICKLET_DMX_ERROR_LED_CONFIG_OFF = 0
  • BRICKLET_DMX_ERROR_LED_CONFIG_ON = 1
  • BRICKLET_DMX_ERROR_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_DMX_ERROR_LED_CONFIG_SHOW_ERROR = 3
function TBrickletDMX.GetErrorLEDConfig: byte

Returns the configuration as set by SetErrorLEDConfig.

The following constants are available for this function:

  • BRICKLET_DMX_ERROR_LED_CONFIG_OFF = 0
  • BRICKLET_DMX_ERROR_LED_CONFIG_ON = 1
  • BRICKLET_DMX_ERROR_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_DMX_ERROR_LED_CONFIG_SHOW_ERROR = 3
function TBrickletDMX.GetAPIVersion: array [0..2] of 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 TBrickletDMX.GetResponseExpected(const functionId: byte): 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.

procedure TBrickletDMX.SetResponseExpected(const functionId: byte; const responseExpected: 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:

  • BRICKLET_DMX_FUNCTION_SET_DMX_MODE = 1
  • BRICKLET_DMX_FUNCTION_WRITE_FRAME = 3
  • BRICKLET_DMX_FUNCTION_SET_FRAME_DURATION = 5
  • BRICKLET_DMX_FUNCTION_SET_COMMUNICATION_LED_CONFIG = 8
  • BRICKLET_DMX_FUNCTION_SET_ERROR_LED_CONFIG = 10
  • BRICKLET_DMX_FUNCTION_SET_FRAME_CALLBACK_CONFIG = 12
  • BRICKLET_DMX_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_DMX_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_DMX_FUNCTION_RESET = 243
  • BRICKLET_DMX_FUNCTION_WRITE_UID = 248
procedure TBrickletDMX.SetResponseExpectedAll(const responseExpected: boolean)

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

procedure TBrickletDMX.GetSPITFPErrorCount(out errorCountAckChecksum: longword; out errorCountMessageChecksum: longword; out errorCountFrame: longword; out errorCountOverflow: longword)

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 TBrickletDMX.SetBootloaderMode(const mode: byte): 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:

  • BRICKLET_DMX_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_DMX_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_DMX_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_DMX_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_DMX_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BRICKLET_DMX_BOOTLOADER_STATUS_OK = 0
  • BRICKLET_DMX_BOOTLOADER_STATUS_INVALID_MODE = 1
  • BRICKLET_DMX_BOOTLOADER_STATUS_NO_CHANGE = 2
  • BRICKLET_DMX_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BRICKLET_DMX_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BRICKLET_DMX_BOOTLOADER_STATUS_CRC_MISMATCH = 5
function TBrickletDMX.GetBootloaderMode: byte

Returns the current bootloader mode, see SetBootloaderMode.

The following constants are available for this function:

  • BRICKLET_DMX_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_DMX_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_DMX_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_DMX_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_DMX_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
procedure TBrickletDMX.SetWriteFirmwarePointer(const pointer: longword)

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 TBrickletDMX.WriteFirmware(const data: array [0..63] of byte): 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.

procedure TBrickletDMX.SetStatusLEDConfig(const config: 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:

  • BRICKLET_DMX_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_DMX_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_DMX_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_DMX_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletDMX.GetStatusLEDConfig: byte

Returns the configuration as set by SetStatusLEDConfig

The following constants are available for this function:

  • BRICKLET_DMX_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_DMX_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_DMX_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_DMX_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletDMX.GetChipTemperature: smallint

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.

procedure TBrickletDMX.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!

procedure TBrickletDMX.WriteUID(const uid: longword)

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 TBrickletDMX.ReadUID: longword

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

procedure TBrickletDMX.GetIdentity(out uid: string; out connectedUid: string; out position: char; out hardwareVersion: array [0..2] of byte; out firmwareVersion: array [0..2] of byte; out deviceIdentifier: word)

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

procedure TBrickletDMX.SetFrameCallbackConfig(const frameStartedCallbackEnabled: boolean; const frameAvailableCallbackEnabled: boolean; const frameCallbackEnabled: boolean; const frameErrorCountCallbackEnabled: boolean)

Enables/Disables the different callbacks. By default the OnFrameStarted callback and OnFrameAvailable callback are enabled while the OnFrame callback and OnFrameErrorCount callback are disabled.

If you want to use the OnFrame callback you can enable it and disable the cb:Frame Available callback at the same time. It becomes redundant in this case.

procedure TBrickletDMX.GetFrameCallbackConfig(out frameStartedCallbackEnabled: boolean; out frameAvailableCallbackEnabled: boolean; out frameCallbackEnabled: boolean; out frameErrorCountCallbackEnabled: boolean)

Returns the frame callback config as set by SetFrameCallbackConfig.

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:

procedure TExample.MyCallback(sender: TBrickletDMX; const param: word);
begin
  WriteLn(param);
end;

dmx.OnExample := {$ifdef FPC}@{$endif}example.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.

property TBrickletDMX.OnFrameStarted
procedure(sender: TBrickletDMX) of object;

This callback is triggered as soon as a new frame write is started. You should send the data for the next frame directly after this callback was triggered.

For an explanation of the general approach see WriteFrame.

This callback can be enabled via SetFrameCallbackConfig.

This callback can only be triggered in master mode.

property TBrickletDMX.OnFrameAvailable
procedure(sender: TBrickletDMX; const frameNumber: longword) of object;

This callback is triggered in slave mode when a new frame was received from the DMX master and it can be read out. You have to read the frame before the master has written the next frame, see ReadFrame for more details.

The parameter is the frame number, it is increased by one with each received frame.

This callback can be enabled via SetFrameCallbackConfig.

This callback can only be triggered in slave mode.

property TBrickletDMX.OnFrameLowLevel
procedure(sender: TBrickletDMX; const frameLength: word; const frameChunkOffset: word; const frameChunkData: array [0..55] of byte; const frameNumber: longword) of object;

This callback is called as soon as a new frame is available (written by the DMX master).

The size of the array is equivalent to the number of channels in the frame. Each byte represents one channel.

This callback can be enabled via SetFrameCallbackConfig.

This callback can only be triggered in slave mode.

property TBrickletDMX.OnFrameErrorCount
procedure(sender: TBrickletDMX; const overrunErrorCount: longword; const framingErrorCount: longword) of object;

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

Constants

const BRICKLET_DMX_DEVICE_IDENTIFIER

This constant is used to identify a DMX Bricklet.

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

const BRICKLET_DMX_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a DMX Bricklet.