Delphi/Lazarus - Segment Display 4x7 Bricklet 2.0

This is the description of the Delphi/Lazarus API bindings for the Segment Display 4x7 Bricklet 2.0. General information and technical specifications for the Segment Display 4x7 Bricklet 2.0 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).

Numeric Value

Download (ExampleNumericValue.pas)

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program ExampleNumericValue;

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

uses
  SysUtils, IPConnection, BrickletSegmentDisplay4x7V2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    sd: TBrickletSegmentDisplay4x7V2;
  public
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Segment Display 4x7 Bricklet 2.0 }

var
  e: TExample;

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

  { Create device object }
  sd := TBrickletSegmentDisplay4x7V2.Create(UID, ipcon);

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

  sd.SetBrightness(7); { Set to full brightness }

  { Show "- 42" on the Display }
  sd.SetNumericValue([-2, -1, 4, 2]);

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

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

Set Segments

Download (ExampleSetSegments.pas)

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program ExampleSetSegments;

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

uses
  SysUtils, IPConnection, BrickletSegmentDisplay4x7V2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    sd: TBrickletSegmentDisplay4x7V2;
  public
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Segment Display 4x7 Bricklet 2.0 }

var
  e: TExample;

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

  { Create device object }
  sd := TBrickletSegmentDisplay4x7V2.Create(UID, ipcon);

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

  sd.SetBrightness(7); { Set to full brightness }

  { Activate all segments }
  sd.SetSegments([true, true, true, true, true, true, true, true],
                 [true, true, true, true, true, true, true, true],
                 [true, true, true, true, true, true, true, true],
                 [true, true, true, true, true, true, true, true], [true, true], true);

  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 TBrickletSegmentDisplay4x7V2.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

segmentDisplay4x7V2 := TBrickletSegmentDisplay4x7V2.Create('YOUR_DEVICE_UID', ipcon);

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

procedure TBrickletSegmentDisplay4x7V2.SetSegments(const digit0: array [0..7] of boolean; const digit1: array [0..7] of boolean; const digit2: array [0..7] of boolean; const digit3: array [0..7] of boolean; const colon: array [0..1] of boolean; const tick: boolean)

Sets the segments of the Segment Display 4x7 Bricklet 2.0 segment-by-segment.

The data is split into the four digits, two colon dots and the tick mark.

The indices of the segments in the digit and colon parameters are as follows:

Indices of segments
procedure TBrickletSegmentDisplay4x7V2.GetSegments(out digit0: array [0..7] of boolean; out digit1: array [0..7] of boolean; out digit2: array [0..7] of boolean; out digit3: array [0..7] of boolean; out colon: array [0..1] of boolean; out tick: boolean)

Returns the segment data as set by SetSegments.

procedure TBrickletSegmentDisplay4x7V2.SetBrightness(const brightness: byte)

The brightness can be set between 0 (dark) and 7 (bright).

The default value is 7.

function TBrickletSegmentDisplay4x7V2.GetBrightness: byte

Returns the brightness as set by SetBrightness.

procedure TBrickletSegmentDisplay4x7V2.SetNumericValue(const value: array [0..3] of shortint)

Sets a numeric value for each of the digits. The values can be between -2 and 15. They represent:

  • -2: minus sign
  • -1: blank
  • 0-9: 0-9
  • 10: A
  • 11: b
  • 12: C
  • 13: d
  • 14: E
  • 15: F

Example: A call with [-2, -1, 4, 2] will result in a display of "- 42".

procedure TBrickletSegmentDisplay4x7V2.SetSelectedSegment(const segment: byte; const value: boolean)

Turns one specified segment on or off.

The indices of the segments are as follows:

Indices of selected segments
function TBrickletSegmentDisplay4x7V2.GetSelectedSegment(const segment: byte): boolean

Returns the value of a single segment.

Advanced Functions

procedure TBrickletSegmentDisplay4x7V2.StartCounter(const valueFrom: smallint; const valueTo: smallint; const increment: smallint; const length: longword)

Starts a counter with the from value that counts to the to value with the each step incremented by increment. The length of the increment is given in ms.

Example: If you set from to 0, to to 100, increment to 1 and length to 1000, a counter that goes from 0 to 100 with one second pause between each increment will be started.

The maximum values for from, to and increment is 9999, the minimum value is -999.

Using a negative increment allows to count backwards.

You can stop the counter at every time by calling SetSegments or SetNumericValue.

function TBrickletSegmentDisplay4x7V2.GetCounterValue: word

Returns the counter value that is currently shown on the display.

If there is no counter running a 0 will be returned.

function TBrickletSegmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.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_SEGMENT_DISPLAY_4X7_V2_FUNCTION_SET_SEGMENTS = 1
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_FUNCTION_SET_BRIGHTNESS = 3
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_FUNCTION_SET_NUMERIC_VALUE = 5
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_FUNCTION_SET_SELECTED_SEGMENT = 6
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_FUNCTION_START_COUNTER = 8
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_FUNCTION_RESET = 243
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_FUNCTION_WRITE_UID = 248
procedure TBrickletSegmentDisplay4x7V2.SetResponseExpectedAll(const responseExpected: boolean)

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

procedure TBrickletSegmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.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_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_STATUS_OK = 0
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
function TBrickletSegmentDisplay4x7V2.GetBootloaderMode: byte

Returns the current bootloader mode, see SetBootloaderMode.

The following constants are available for this function:

  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
procedure TBrickletSegmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.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_SEGMENT_DISPLAY_4X7_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletSegmentDisplay4x7V2.GetStatusLEDConfig: byte

Returns the configuration as set by SetStatusLEDConfig

The following constants are available for this function:

  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_SEGMENT_DISPLAY_4X7_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletSegmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.ReadUID: longword

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

procedure TBrickletSegmentDisplay4x7V2.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.

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: TBrickletSegmentDisplay4x7V2; const param: word);
begin
  WriteLn(param);
end;

segmentDisplay4x7V2.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 TBrickletSegmentDisplay4x7V2.OnCounterFinished
procedure(sender: TBrickletSegmentDisplay4x7V2) of object;

This callback is triggered when the counter (see StartCounter) is finished.

Constants

const BRICKLET_SEGMENT_DISPLAY_4X7_V2_DEVICE_IDENTIFIER

This constant is used to identify a Segment Display 4x7 Bricklet 2.0.

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_SEGMENT_DISPLAY_4X7_V2_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Segment Display 4x7 Bricklet 2.0.