Delphi/Lazarus - Segment Display 4x7 Bricklet¶

Simple¶

Download (ExampleSimple.pas)

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program ExampleSimple;

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

uses
  SysUtils, IPConnection, BrickletSegmentDisplay4x7;

type
  TExample = class
  private
    ipcon: TIPConnection;
    sd: TBrickletSegmentDisplay4x7;
  public
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Segment Display 4x7 Bricklet }
  DIGITS : array [0..15] of byte = ($3f,$06,$5b,$4f,
                                    $66,$6d,$7d,$07,
                                    $7f,$6f,$77,$7c,
                                    $39,$5e,$79,$71);

var
  e: TExample;

procedure TExample.Execute;
var segments: array [0..3] of byte;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  sd := TBrickletSegmentDisplay4x7.Create(UID, ipcon);

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

  { Write "4223" to the display with full brightness without colon }
  segments[0] := DIGITS[4];
  segments[1] := DIGITS[2];
  segments[2] := DIGITS[2];
  segments[3] := DIGITS[3];
  sd.SetSegments(segments, 7, false);

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

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

Basic Functions¶

constructor TBrickletSegmentDisplay4x7.Create(const uid: string; ipcon: TIPConnection)¶

Parameters:	uid – Type: string ipcon – Type: TIPConnection
Returns:	segmentDisplay4x7 – Type: TBrickletSegmentDisplay4x7

Creates an object with the unique device ID uid:

segmentDisplay4x7 := TBrickletSegmentDisplay4x7.Create('YOUR_DEVICE_UID', ipcon);

This object can then be used after the IP Connection is connected.

procedure TBrickletSegmentDisplay4x7.SetSegments(const segments: array [0..3] of byte; const brightness: byte; const colon: boolean)¶

Parameters:	segments – Type: array [0..3] of byte, Range: [0 to 127] brightness – Type: byte, Range: [0 to 7] colon – Type: boolean

The 7-segment display can be set with bitmaps. Every bit controls one segment:

For example to set a "5" you would want to activate segments 0, 2, 3, 5 and 6. This is represented by the number 0b01101101 = 0x6d = 109.

The brightness can be set between 0 (dark) and 7 (bright). The colon parameter turns the colon of the display on or off.

procedure TBrickletSegmentDisplay4x7.GetSegments(out segments: array [0..3] of byte; out brightness: byte; out colon: boolean)¶

Output Parameters:	segments – Type: array [0..3] of byte, Range: [0 to 127] brightness – Type: byte, Range: [0 to 7] colon – Type: boolean

Returns the segment, brightness and color data as set by SetSegments.

Advanced Functions¶

procedure TBrickletSegmentDisplay4x7.StartCounter(const valueFrom: smallint; const valueTo: smallint; const increment: smallint; const length: longword)¶

Parameters:	valueFrom – Type: smallint, Range: [-999 to 9999] valueTo – Type: smallint, Range: [-999 to 9999] increment – Type: smallint, Range: [-999 to 9999] length – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1]

Starts a counter with the from value that counts to the to value with the each step incremented by increment. length is the pause between each increment.

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.

Using a negative increment allows to count backwards.

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

function TBrickletSegmentDisplay4x7.GetCounterValue: word¶

Returns:	value – Type: word, Range: [-999 to 9999]

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

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

procedure TBrickletSegmentDisplay4x7.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)¶

Output Parameters:

uid – Type: string, Length: up to 8 connectedUid – Type: string, Length: up to 8 position – Type: char, Range: ['a' to 'h', 'z'] hardwareVersion – Type: array [0..2] of byte 0: major – Type: byte, Range: [0 to 255] 1: minor – Type: byte, Range: [0 to 255] 2: revision – Type: byte, Range: [0 to 255] firmwareVersion – Type: array [0..2] of byte 0: major – Type: byte, Range: [0 to 255] 1: minor – Type: byte, Range: [0 to 255] 2: revision – Type: byte, Range: [0 to 255] deviceIdentifier – Type: word, Range: [0 to 216 - 1]

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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

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: TBrickletSegmentDisplay4x7; const value: longint);
begin
  WriteLn(Format('Value: %d', [value]));
end;

segmentDisplay4x7.OnExample := {$ifdef FPC}@{$endif}example.MyCallback;

The available callback properties and their parameter types are described below.

property TBrickletSegmentDisplay4x7.OnCounterFinished¶

procedure(sender: TBrickletSegmentDisplay4x7) of object;

Callback Parameters:	sender – Type: TBrickletSegmentDisplay4x7

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

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

function TBrickletSegmentDisplay4x7.GetAPIVersion: array [0..2] of byte¶

Output Parameters:	apiVersion – Type: array [0..2] of byte 0: major – Type: byte, Range: [0 to 255] 1: minor – Type: byte, Range: [0 to 255] 2: revision – Type: byte, Range: [0 to 255]

Returns the version of the API definition 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 TBrickletSegmentDisplay4x7.GetResponseExpected(const functionId: byte): boolean¶

Parameters:	functionId – Type: byte, Range: See constants
Returns:	responseExpected – Type: 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

• BRICKLET_SEGMENT_DISPLAY_4X7_FUNCTION_SET_SEGMENTS = 1
• BRICKLET_SEGMENT_DISPLAY_4X7_FUNCTION_START_COUNTER = 3

procedure TBrickletSegmentDisplay4x7.SetResponseExpected(const functionId: byte; const responseExpected: boolean)¶

Parameters:	functionId – Type: byte, Range: See constants responseExpected – Type: 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

• BRICKLET_SEGMENT_DISPLAY_4X7_FUNCTION_SET_SEGMENTS = 1
• BRICKLET_SEGMENT_DISPLAY_4X7_FUNCTION_START_COUNTER = 3

procedure TBrickletSegmentDisplay4x7.SetResponseExpectedAll(const responseExpected: boolean)¶

Parameters:	responseExpected – Type: boolean

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

Constants¶

const BRICKLET_SEGMENT_DISPLAY_4X7_DEVICE_IDENTIFIER¶

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

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

const BRICKLET_SEGMENT_DISPLAY_4X7_DEVICE_DISPLAY_NAME¶

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