Delphi/Lazarus - Rotary Encoder 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, BrickletRotaryEncoder;

type
  TExample = class
  private
    ipcon: TIPConnection;
    re: TBrickletRotaryEncoder;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

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

  { Create device object }
  re := TBrickletRotaryEncoder.Create(UID, ipcon);

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

  { Get current count without reset }
  count := re.GetCount(false);
  WriteLn(Format('Count: %d', [count]));

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

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

Callback¶

Download (ExampleCallback.pas)

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program ExampleCallback;

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

uses
  SysUtils, IPConnection, BrickletRotaryEncoder;

type
  TExample = class
  private
    ipcon: TIPConnection;
    re: TBrickletRotaryEncoder;
  public
    procedure CountCB(sender: TBrickletRotaryEncoder; const count: longint);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for count callback }
procedure TExample.CountCB(sender: TBrickletRotaryEncoder; const count: longint);
begin
  WriteLn(Format('Count: %d', [count]));
end;

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

  { Create device object }
  re := TBrickletRotaryEncoder.Create(UID, ipcon);

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

  { Register count callback to procedure CountCB }
  re.OnCount := {$ifdef FPC}@{$endif}CountCB;

  { Set period for count callback to 0.05s (50ms)
    Note: The count callback is only called every 0.05 seconds
          if the count has changed since the last call! }
  re.SetCountCallbackPeriod(50);

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

Parameters:	uid – Type: string ipcon – Type: TIPConnection
Returns:	rotaryEncoder – Type: TBrickletRotaryEncoder

Creates an object with the unique device ID uid:

rotaryEncoder := TBrickletRotaryEncoder.Create('YOUR_DEVICE_UID', ipcon);

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

function TBrickletRotaryEncoder.GetCount(const reset: boolean): longint¶

Parameters:	reset – Type: boolean
Returns:	count – Type: longint, Range: [-231 to 231 - 1]

Returns the current count of the encoder. If you set reset to true, the count is set back to 0 directly after the current count is read.

The encoder has 24 steps per rotation

Turning the encoder to the left decrements the counter, so a negative count is possible.

function TBrickletRotaryEncoder.IsPressed: boolean¶

Returns:	pressed – Type: boolean

Returns true if the button is pressed and false otherwise.

It is recommended to use the OnPressed and OnReleased callbacks to handle the button.

Advanced Functions¶

procedure TBrickletRotaryEncoder.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.

Callback Configuration Functions¶

procedure TBrickletRotaryEncoder.SetCountCallbackPeriod(const period: longword)¶

Parameters:	period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Sets the period with which the OnCount callback is triggered periodically. A value of 0 turns the callback off.

The OnCount callback is only triggered if the count has changed since the last triggering.

function TBrickletRotaryEncoder.GetCountCallbackPeriod: longword¶

Returns:	period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by SetCountCallbackPeriod.

procedure TBrickletRotaryEncoder.SetCountCallbackThreshold(const option: char; const min: longint; const max: longint)¶

Parameters:	option – Type: char, Range: See constants, Default: 'x' min – Type: longint, Range: [-231 to 231 - 1], Default: 0 max – Type: longint, Range: [-231 to 231 - 1], Default: 0

Sets the thresholds for the OnCountReached callback.

The following options are possible:

Option	Description
'x'	Callback is turned off
'o'	Callback is triggered when the count is outside the min and max values
'i'	Callback is triggered when the count is inside the min and max values
'<'	Callback is triggered when the count is smaller than the min value (max is ignored)
'>'	Callback is triggered when the count is greater than the min value (max is ignored)

The following constants are available for this function:

For option:

• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_OFF = 'x'
• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_OUTSIDE = 'o'
• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_INSIDE = 'i'
• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_SMALLER = '<'
• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_GREATER = '>'

procedure TBrickletRotaryEncoder.GetCountCallbackThreshold(out option: char; out min: longint; out max: longint)¶

Output Parameters:	option – Type: char, Range: See constants, Default: 'x' min – Type: longint, Range: [-231 to 231 - 1], Default: 0 max – Type: longint, Range: [-231 to 231 - 1], Default: 0

Returns the threshold as set by SetCountCallbackThreshold.

The following constants are available for this function:

For option:

• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_OFF = 'x'
• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_OUTSIDE = 'o'
• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_INSIDE = 'i'
• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_SMALLER = '<'
• BRICKLET_ROTARY_ENCODER_THRESHOLD_OPTION_GREATER = '>'

procedure TBrickletRotaryEncoder.SetDebouncePeriod(const debounce: longword)¶

Parameters:	debounce – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Sets the period with which the threshold callback

• OnCountReached

is triggered, if the thresholds

• SetCountCallbackThreshold

keeps being reached.

function TBrickletRotaryEncoder.GetDebouncePeriod: longword¶

Returns:	debounce – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by SetDebouncePeriod.

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

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

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

property TBrickletRotaryEncoder.OnCount¶

procedure(sender: TBrickletRotaryEncoder; const count: longint) of object;

Callback Parameters:	sender – Type: TBrickletRotaryEncoder count – Type: longint, Range: [-231 to 231 - 1]

This callback is triggered periodically with the period that is set by SetCountCallbackPeriod. The parameter is the count of the encoder.

The OnCount callback is only triggered if the count has changed since the last triggering.

property TBrickletRotaryEncoder.OnCountReached¶

procedure(sender: TBrickletRotaryEncoder; const count: longint) of object;

Callback Parameters:	sender – Type: TBrickletRotaryEncoder count – Type: longint, Range: [-231 to 231 - 1]

This callback is triggered when the threshold as set by SetCountCallbackThreshold is reached. The parameter is the count of the encoder.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by SetDebouncePeriod.

property TBrickletRotaryEncoder.OnPressed¶

procedure(sender: TBrickletRotaryEncoder) of object;

Callback Parameters:	sender – Type: TBrickletRotaryEncoder

This callback is triggered when the button is pressed.

property TBrickletRotaryEncoder.OnReleased¶

procedure(sender: TBrickletRotaryEncoder) of object;

Callback Parameters:	sender – Type: TBrickletRotaryEncoder

This callback is triggered when the button is released.

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 TBrickletRotaryEncoder.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 TBrickletRotaryEncoder.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_ROTARY_ENCODER_FUNCTION_SET_COUNT_CALLBACK_PERIOD = 2
• BRICKLET_ROTARY_ENCODER_FUNCTION_SET_COUNT_CALLBACK_THRESHOLD = 4
• BRICKLET_ROTARY_ENCODER_FUNCTION_SET_DEBOUNCE_PERIOD = 6

procedure TBrickletRotaryEncoder.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_ROTARY_ENCODER_FUNCTION_SET_COUNT_CALLBACK_PERIOD = 2
• BRICKLET_ROTARY_ENCODER_FUNCTION_SET_COUNT_CALLBACK_THRESHOLD = 4
• BRICKLET_ROTARY_ENCODER_FUNCTION_SET_DEBOUNCE_PERIOD = 6

procedure TBrickletRotaryEncoder.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_ROTARY_ENCODER_DEVICE_IDENTIFIER¶

This constant is used to identify a Rotary Encoder 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_ROTARY_ENCODER_DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a Rotary Encoder Bricklet.