Delphi/Lazarus - Ambient Light Bricklet 2.0

This is the description of the Delphi/Lazarus API bindings for the Ambient Light Bricklet 2.0. General information and technical specifications for the Ambient Light 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).

Simple

Download (ExampleSimple.pas)

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program ExampleSimple;

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

uses
  SysUtils, IPConnection, BrickletAmbientLightV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    al: TBrickletAmbientLightV2;
  public
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Ambient Light Bricklet 2.0 }

var
  e: TExample;

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

  { Create device object }
  al := TBrickletAmbientLightV2.Create(UID, ipcon);

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

  { Get current illuminance }
  illuminance := al.GetIlluminance;
  WriteLn(Format('Illuminance: %f lx', [illuminance/100.0]));

  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, BrickletAmbientLightV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    al: TBrickletAmbientLightV2;
  public
    procedure IlluminanceCB(sender: TBrickletAmbientLightV2; const illuminance: longword);
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Ambient Light Bricklet 2.0 }

var
  e: TExample;

{ Callback procedure for illuminance callback }
procedure TExample.IlluminanceCB(sender: TBrickletAmbientLightV2;
                                 const illuminance: longword);
begin
  WriteLn(Format('Illuminance: %f lx', [illuminance/100.0]));
end;

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

  { Create device object }
  al := TBrickletAmbientLightV2.Create(UID, ipcon);

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

  { Register illuminance callback to procedure IlluminanceCB }
  al.OnIlluminance := {$ifdef FPC}@{$endif}IlluminanceCB;

  { Set period for illuminance callback to 1s (1000ms)
    Note: The illuminance callback is only called every second
          if the illuminance has changed since the last call! }
  al.SetIlluminanceCallbackPeriod(1000);

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

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

Threshold

Download (ExampleThreshold.pas)

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program ExampleThreshold;

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

uses
  SysUtils, IPConnection, BrickletAmbientLightV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    al: TBrickletAmbientLightV2;
  public
    procedure IlluminanceReachedCB(sender: TBrickletAmbientLightV2;
                                   const illuminance: longword);
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Ambient Light Bricklet 2.0 }

var
  e: TExample;

{ Callback procedure for illuminance reached callback }
procedure TExample.IlluminanceReachedCB(sender: TBrickletAmbientLightV2;
                                        const illuminance: longword);
begin
  WriteLn(Format('Illuminance: %f lx', [illuminance/100.0]));
  WriteLn('Too bright, close the curtains!');
end;

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

  { Create device object }
  al := TBrickletAmbientLightV2.Create(UID, ipcon);

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

  { Get threshold callbacks with a debounce time of 10 seconds (10000ms) }
  al.SetDebouncePeriod(10000);

  { Register illuminance reached callback to procedure IlluminanceReachedCB }
  al.OnIlluminanceReached := {$ifdef FPC}@{$endif}IlluminanceReachedCB;

  { Configure threshold for illuminance "greater than 500 lx" }
  al.SetIlluminanceCallbackThreshold('>', 500*100, 0);

  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 TBrickletAmbientLightV2.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

ambientLightV2 := TBrickletAmbientLightV2.Create('YOUR_DEVICE_UID', ipcon);

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

function TBrickletAmbientLightV2.GetIlluminance: longword

Returns the illuminance of the ambient light sensor. The measurement range goes up to about 100000lux, but above 64000lux the precision starts to drop. The illuminance is given in lux/100, i.e. a value of 450000 means that an illuminance of 4500lux is measured.

Changed in version 2.0.2 (Plugin): An illuminance of 0lux indicates that the sensor is saturated and the configuration should be modified, see SetConfiguration.

If you want to get the illuminance periodically, it is recommended to use the OnIlluminance callback and set the period with SetIlluminanceCallbackPeriod.

Advanced Functions

procedure TBrickletAmbientLightV2.SetConfiguration(const illuminanceRange: byte; const integrationTime: byte)

Sets the configuration. It is possible to configure an illuminance range between 0-600lux and 0-64000lux and an integration time between 50ms and 400ms.

New in version 2.0.2 (Plugin): The unlimited illuminance range allows to measure up to about 100000lux, but above 64000lux the precision starts to drop.

A smaller illuminance range increases the resolution of the data. A longer integration time will result in less noise on the data.

Changed in version 2.0.2 (Plugin): If the actual measure illuminance is out-of-range then the current illuminance range maximum +0.01lux is reported by GetIlluminance and the OnIlluminance callback. For example, 800001 for the 0-8000lux range.

Changed in version 2.0.2 (Plugin): With a long integration time the sensor might be saturated before the measured value reaches the maximum of the selected illuminance range. In this case 0lux is reported by GetIlluminance and the OnIlluminance callback.

If the measurement is out-of-range or the sensor is saturated then you should configure the next higher illuminance range. If the highest range is already in use, then start to reduce the integration time.

The default values are 0-8000lux illuminance range and 200ms integration time.

The following constants are available for this function:

  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_UNLIMITED = 6
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_64000LUX = 0
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_32000LUX = 1
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_16000LUX = 2
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_8000LUX = 3
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_1300LUX = 4
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_600LUX = 5
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_50MS = 0
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_100MS = 1
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_150MS = 2
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_200MS = 3
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_250MS = 4
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_300MS = 5
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_350MS = 6
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_400MS = 7
procedure TBrickletAmbientLightV2.GetConfiguration(out illuminanceRange: byte; out integrationTime: byte)

Returns the configuration as set by SetConfiguration.

The following constants are available for this function:

  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_UNLIMITED = 6
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_64000LUX = 0
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_32000LUX = 1
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_16000LUX = 2
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_8000LUX = 3
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_1300LUX = 4
  • BRICKLET_AMBIENT_LIGHT_V2_ILLUMINANCE_RANGE_600LUX = 5
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_50MS = 0
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_100MS = 1
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_150MS = 2
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_200MS = 3
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_250MS = 4
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_300MS = 5
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_350MS = 6
  • BRICKLET_AMBIENT_LIGHT_V2_INTEGRATION_TIME_400MS = 7
function TBrickletAmbientLightV2.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 TBrickletAmbientLightV2.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 TBrickletAmbientLightV2.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_AMBIENT_LIGHT_V2_FUNCTION_SET_ILLUMINANCE_CALLBACK_PERIOD = 2
  • BRICKLET_AMBIENT_LIGHT_V2_FUNCTION_SET_ILLUMINANCE_CALLBACK_THRESHOLD = 4
  • BRICKLET_AMBIENT_LIGHT_V2_FUNCTION_SET_DEBOUNCE_PERIOD = 6
  • BRICKLET_AMBIENT_LIGHT_V2_FUNCTION_SET_CONFIGURATION = 8
procedure TBrickletAmbientLightV2.SetResponseExpectedAll(const responseExpected: boolean)

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

procedure TBrickletAmbientLightV2.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.

Callback Configuration Functions

procedure TBrickletAmbientLightV2.SetIlluminanceCallbackPeriod(const period: longword)

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

The OnIlluminance callback is only triggered if the illuminance has changed since the last triggering.

The default value is 0.

function TBrickletAmbientLightV2.GetIlluminanceCallbackPeriod: longword

Returns the period as set by SetIlluminanceCallbackPeriod.

procedure TBrickletAmbientLightV2.SetIlluminanceCallbackThreshold(const option: char; const min: longword; const max: longword)

Sets the thresholds for the OnIlluminanceReached callback.

The following options are possible:

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

The default value is ('x', 0, 0).

The following constants are available for this function:

  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletAmbientLightV2.GetIlluminanceCallbackThreshold(out option: char; out min: longword; out max: longword)

Returns the threshold as set by SetIlluminanceCallbackThreshold.

The following constants are available for this function:

  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_AMBIENT_LIGHT_V2_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletAmbientLightV2.SetDebouncePeriod(const debounce: longword)

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

function TBrickletAmbientLightV2.GetDebouncePeriod: longword

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: TBrickletAmbientLightV2; const param: word);
begin
  WriteLn(param);
end;

ambientLightV2.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 TBrickletAmbientLightV2.OnIlluminance
procedure(sender: TBrickletAmbientLightV2; const illuminance: longword) of object;

This callback is triggered periodically with the period that is set by SetIlluminanceCallbackPeriod. The parameter is the illuminance of the ambient light sensor.

The OnIlluminance callback is only triggered if the illuminance has changed since the last triggering.

property TBrickletAmbientLightV2.OnIlluminanceReached
procedure(sender: TBrickletAmbientLightV2; const illuminance: longword) of object;

This callback is triggered when the threshold as set by SetIlluminanceCallbackThreshold is reached. The parameter is the illuminance of the ambient light sensor.

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

Constants

const BRICKLET_AMBIENT_LIGHT_V2_DEVICE_IDENTIFIER

This constant is used to identify a Ambient Light 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_AMBIENT_LIGHT_V2_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Ambient Light Bricklet 2.0.