Delphi/Lazarus - Multi Touch Bricklet¶

Simple¶

Download (ExampleSimple.pas)

 1program ExampleSimple;
 2
 3{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
 4{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}
 5
 6uses
 7  SysUtils, IPConnection, BrickletMultiTouch;
 8
 9type
10  TExample = class
11  private
12    ipcon: TIPConnection;
13    mt: TBrickletMultiTouch;
14  public
15    procedure Execute;
16  end;
17
18const
19  HOST = 'localhost';
20  PORT = 4223;
21  UID = 'XYZ'; { Change XYZ to the UID of your Multi Touch Bricklet }
22
23var
24  e: TExample;
25
26procedure TExample.Execute;
27var state: word; i: integer;
28begin
29  { Create IP connection }
30  ipcon := TIPConnection.Create;
31
32  { Create device object }
33  mt := TBrickletMultiTouch.Create(UID, ipcon);
34
35  { Connect to brickd }
36  ipcon.Connect(HOST, PORT);
37  { Don't use device before ipcon is connected }
38
39  { Get current touch state }
40  state := mt.GetTouchState;
41
42  if (state And (1 Shl 12)) = (1 Shl 12) then begin
43    Write('In proximity, ');
44  end;
45
46  if (state And $fff) = 0 then begin
47    WriteLn('No electrodes touched');
48  end
49  else begin
50    Write('Electrodes ');
51    for i := 0 to 11 do begin
52      if (state And (1 Shl i)) = (1 Shl i) then begin
53        Write(IntToStr(i) + ' ');
54      end;
55    end;
56    WriteLn('touched');
57  end;
58  WriteLn('');
59
60  WriteLn('Press key to exit');
61  ReadLn;
62  ipcon.Destroy; { Calls ipcon.Disconnect internally }
63end;
64
65begin
66  e := TExample.Create;
67  e.Execute;
68  e.Destroy;
69end.

Callback¶

Download (ExampleCallback.pas)

 1program ExampleCallback;
 2
 3{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
 4{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}
 5
 6uses
 7  SysUtils, IPConnection, BrickletMultiTouch;
 8
 9type
10  TExample = class
11  private
12    ipcon: TIPConnection;
13    mt: TBrickletMultiTouch;
14  public
15    procedure TouchStateCB(sender: TBrickletMultiTouch; const state: word);
16    procedure Execute;
17  end;
18
19const
20  HOST = 'localhost';
21  PORT = 4223;
22  UID = 'XYZ'; { Change XYZ to the UID of your Multi Touch Bricklet }
23
24var
25  e: TExample;
26
27{ Callback procedure for touch state callback }
28procedure TExample.TouchStateCB(sender: TBrickletMultiTouch; const state: word);
29var i: integer;
30begin
31  if (state And (1 Shl 12)) = (1 Shl 12) then begin
32    Write('In proximity, ');
33  end;
34
35  if (state And $fff) = 0 then begin
36    WriteLn('No electrodes touched');
37  end
38  else begin
39    Write('Electrodes ');
40    for i := 0 to 11 do begin
41      if (state And (1 Shl i)) = (1 Shl i) then begin
42        Write(IntToStr(i) + ' ');
43      end;
44    end;
45    WriteLn('touched');
46  end;
47end;
48
49procedure TExample.Execute;
50begin
51  { Create IP connection }
52  ipcon := TIPConnection.Create;
53
54  { Create device object }
55  mt := TBrickletMultiTouch.Create(UID, ipcon);
56
57  { Connect to brickd }
58  ipcon.Connect(HOST, PORT);
59  { Don't use device before ipcon is connected }
60
61  { Register touch state callback to procedure TouchStateCB }
62  mt.OnTouchState := {$ifdef FPC}@{$endif}TouchStateCB;
63
64  WriteLn('Press key to exit');
65  ReadLn;
66  ipcon.Destroy; { Calls ipcon.Disconnect internally }
67end;
68
69begin
70  e := TExample.Create;
71  e.Execute;
72  e.Destroy;
73end.

Basic Functions¶

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

Parameters:	uid – Type: string ipcon – Type: TIPConnection
Returns:	multiTouch – Type: TBrickletMultiTouch

Creates an object with the unique device ID uid:

multiTouch := TBrickletMultiTouch.Create('YOUR_DEVICE_UID', ipcon);

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

function TBrickletMultiTouch.GetTouchState: word¶

Returns:	state – Type: word, Range: [0 to 213 - 1]

Returns the current touch state. The state is given as a bitfield.

Bits 0 to 11 represent the 12 electrodes and bit 12 represents the proximity.

If an electrode is touched, the corresponding bit is true. If a hand or similar is in proximity to the electrodes, bit 12 is true.

Example: The state 4103 = 0x1007 = 0b1000000000111 means that electrodes 0, 1 and 2 are touched and that something is in the proximity of the electrodes.

The proximity is activated with a distance of 1-2cm. An electrode is already counted as touched if a finger is nearly touching the electrode. This means that you can put a piece of paper or foil or similar on top of a electrode to build a touch panel with a professional look.

procedure TBrickletMultiTouch.Recalibrate¶

Recalibrates the electrodes. Call this function whenever you changed or moved you electrodes.

procedure TBrickletMultiTouch.SetElectrodeConfig(const enabledElectrodes: word)¶

Parameters:	enabledElectrodes – Type: word, Range: [0 to 213 - 1], Default: 213 - 1

Enables/disables electrodes with a bitfield (see GetTouchState).

True enables the electrode, false disables the electrode. A disabled electrode will always return false as its state. If you don't need all electrodes you can disable the electrodes that are not needed.

It is recommended that you disable the proximity bit (bit 12) if the proximity feature is not needed. This will reduce the amount of traffic that is produced by the OnTouchState callback.

Disabling electrodes will also reduce power consumption.

Default: 8191 = 0x1FFF = 0b1111111111111 (all electrodes and proximity feature enabled)

function TBrickletMultiTouch.GetElectrodeConfig: word¶

Returns:	enabledElectrodes – Type: word, Range: [0 to 213 - 1], Default: 213 - 1

Returns the electrode configuration, as set by SetElectrodeConfig.

procedure TBrickletMultiTouch.SetElectrodeSensitivity(const sensitivity: byte)¶

Parameters:	sensitivity – Type: byte, Range: [5 to 201], Default: 181

Sets the sensitivity of the electrodes. An electrode with a high sensitivity will register a touch earlier then an electrode with a low sensitivity.

If you build a big electrode you might need to decrease the sensitivity, since the area that can be charged will get bigger. If you want to be able to activate an electrode from further away you need to increase the sensitivity.

After a new sensitivity is set, you likely want to call Recalibrate to calibrate the electrodes with the newly defined sensitivity.

function TBrickletMultiTouch.GetElectrodeSensitivity: byte¶

Returns:	sensitivity – Type: byte, Range: [5 to 201], Default: 181

Returns the current sensitivity, as set by SetElectrodeSensitivity.

Advanced Functions¶

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

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

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

property TBrickletMultiTouch.OnTouchState¶

procedure(sender: TBrickletMultiTouch; const state: word) of object;

Callback Parameters:	sender – Type: TBrickletMultiTouch state – Type: word, Range: [0 to 213 - 1]

Returns the current touch state, see GetTouchState for information about the state.

This callback is triggered every time the touch state changes.

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 TBrickletMultiTouch.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 TBrickletMultiTouch.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_MULTI_TOUCH_FUNCTION_RECALIBRATE = 2

• BRICKLET_MULTI_TOUCH_FUNCTION_SET_ELECTRODE_CONFIG = 3

• BRICKLET_MULTI_TOUCH_FUNCTION_SET_ELECTRODE_SENSITIVITY = 6

procedure TBrickletMultiTouch.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_MULTI_TOUCH_FUNCTION_RECALIBRATE = 2

• BRICKLET_MULTI_TOUCH_FUNCTION_SET_ELECTRODE_CONFIG = 3

• BRICKLET_MULTI_TOUCH_FUNCTION_SET_ELECTRODE_SENSITIVITY = 6

procedure TBrickletMultiTouch.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_MULTI_TOUCH_DEVICE_IDENTIFIER¶

This constant is used to identify a Multi Touch 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_MULTI_TOUCH_DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a Multi Touch Bricklet.