Delphi/Lazarus - OLED 128x64 Bricklet

This is the description of the Delphi/Lazarus API bindings for the OLED 128x64 Bricklet. General information and technical specifications for the OLED 128x64 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).

Hello World

Download (ExampleHelloWorld.pas)

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program ExampleHelloWorld;

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

uses
  SysUtils, IPConnection, BrickletOLED128x64;

type
  TExample = class
  private
    ipcon: TIPConnection;
    oled: TBrickletOLED128x64;
  public
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your OLED 128x64 Bricklet }

var
  e: TExample;

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

  { Create device object }
  oled := TBrickletOLED128x64.Create(UID, ipcon);

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

  { Clear display }
  oled.ClearDisplay;

  { Write "Hello World" starting from upper left corner of the screen }
  oled.WriteLine(0, 0, 'Hello World');

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

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

Pixel Matrix

Download (ExamplePixelMatrix.pas)

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program ExamplePixelMatrix;

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

uses
  Math, SysUtils, IPConnection, BrickletOLED128x64;

const
  WIDTH = 128;
  HEIGHT = 64;

type
  TPixels = array [0..(HEIGHT - 1), 0..(WIDTH - 1)] of boolean;
  TExample = class
  private
    ipcon: TIPConnection;
    oled: TBrickletOLED128x64;
  public
    procedure DrawMatrix(pixels: TPixels);
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your OLED 128x64 Bricklet }

var
  e: TExample;

procedure TExample.DrawMatrix(pixels: TPixels);
var row, column, bit, i: integer;
    pages: array [0..(HEIGHT div 8 - 1), 0..(WIDTH - 1)] of byte;
    section: array [0..63] of byte;
begin
  for row := 0 to HEIGHT div 8 - 1 do begin
    for column := 0 to WIDTH - 1 do begin
      pages[row][column] := 0;
      for bit := 0 to 7 do begin
        if (pixels[(row * 8) + bit, column]) then begin
          pages[row][column] := pages[row][column] or (1 << bit);
        end;
      end;
    end;
  end;
  oled.NewWindow(0, WIDTH - 1, 0, HEIGHT div 8 - 1);
  for row := 0 to HEIGHT div 8 - 1 do begin
    column := 0;
    while column < WIDTH - 1 do begin
      for i := 0 to 63 do begin
        section[i] := pages[row][column + i];
      end;
      oled.write(section);
      column := column + 64;
    end;
  end;
end;

procedure TExample.Execute;
var row, column: integer; pixels: TPixels;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  oled := TBrickletOLED128x64.Create(UID, ipcon);

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

  { Clear display }
  oled.ClearDisplay;

  { Draw checkerboard pattern }
  for row := 0 to HEIGHT - 1 do begin
    for column := 0 to WIDTH - 1 do begin
      pixels[row, column] := (row div 8) mod 2 = (column div 8) mod 2;
    end;
  end;

  e.DrawMatrix(pixels);

  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 TBrickletOLED128x64.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

oled128x64 := TBrickletOLED128x64.Create('YOUR_DEVICE_UID', ipcon);

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

procedure TBrickletOLED128x64.Write(const data: array [0..63] of byte)

Appends 64 byte of data to the window as set by NewWindow.

Each row has a height of 8 pixels which corresponds to one byte of data.

Example: if you call NewWindow with column from 0 to 127 and row from 0 to 7 (the whole display) each call of Write (red arrow) will write half of a row.

Display pixel order

The LSB (D0) of each data byte is at the top and the MSB (D7) is at the bottom of the row.

The next call of Write will write the second half of the row and the next two the second row and so on. To fill the whole display you need to call Write 16 times.

procedure TBrickletOLED128x64.NewWindow(const columnFrom: byte; const columnTo: byte; const rowFrom: byte; const rowTo: byte)

Sets the window in which you can write with Write. One row has a height of 8 pixels.

The columns have a range of 0 to 127 and the rows have a range of 0 to 7.

procedure TBrickletOLED128x64.ClearDisplay

Clears the current content of the window as set by NewWindow.

procedure TBrickletOLED128x64.WriteLine(const line: byte; const position: byte; const text: string)

Writes text to a specific line (0 to 7) with a specific position (0 to 25). The text can have a maximum of 26 characters.

For example: (1, 10, "Hello") will write Hello in the middle of the second line of the display.

You can draw to the display with Write and then add text to it afterwards.

The display uses a special 5x7 pixel charset. You can view the characters of the charset in Brick Viewer.

Advanced Functions

procedure TBrickletOLED128x64.SetDisplayConfiguration(const contrast: byte; const invert: boolean)

Sets the configuration of the display.

You can set a contrast value from 0 to 255 and you can invert the color (black/white) of the display.

The default values are contrast 143 and inverting off.

procedure TBrickletOLED128x64.GetDisplayConfiguration(out contrast: byte; out invert: boolean)

Returns the configuration as set by SetDisplayConfiguration.

function TBrickletOLED128x64.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 TBrickletOLED128x64.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 TBrickletOLED128x64.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_OLED_128X64_FUNCTION_WRITE = 1
  • BRICKLET_OLED_128X64_FUNCTION_NEW_WINDOW = 2
  • BRICKLET_OLED_128X64_FUNCTION_CLEAR_DISPLAY = 3
  • BRICKLET_OLED_128X64_FUNCTION_SET_DISPLAY_CONFIGURATION = 4
  • BRICKLET_OLED_128X64_FUNCTION_WRITE_LINE = 6
procedure TBrickletOLED128x64.SetResponseExpectedAll(const responseExpected: boolean)

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

procedure TBrickletOLED128x64.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.

Constants

const BRICKLET_OLED_128X64_DEVICE_IDENTIFIER

This constant is used to identify a OLED 128x64 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_OLED_128X64_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a OLED 128x64 Bricklet.