Delphi/Lazarus - Accelerometer 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, BrickletAccelerometer;

type
  TExample = class
  private
    ipcon: TIPConnection;
    a: TBrickletAccelerometer;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

procedure TExample.Execute;
var x, y, z: smallint;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  a := TBrickletAccelerometer.Create(UID, ipcon);

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

  { Get current acceleration }
  a.GetAcceleration(x, y, z);

  WriteLn(Format('Acceleration [X]: %f g', [x/1000.0]));
  WriteLn(Format('Acceleration [Y]: %f g', [y/1000.0]));
  WriteLn(Format('Acceleration [Z]: %f g', [z/1000.0]));

  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, BrickletAccelerometer;

type
  TExample = class
  private
    ipcon: TIPConnection;
    a: TBrickletAccelerometer;
  public
    procedure AccelerationCB(sender: TBrickletAccelerometer; const x: smallint;
                             const y: smallint; const z: smallint);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for acceleration callback }
procedure TExample.AccelerationCB(sender: TBrickletAccelerometer; const x: smallint;
                                  const y: smallint; const z: smallint);
begin
  WriteLn(Format('Acceleration [X]: %f g', [x/1000.0]));
  WriteLn(Format('Acceleration [Y]: %f g', [y/1000.0]));
  WriteLn(Format('Acceleration [Z]: %f g', [z/1000.0]));
  WriteLn('');
end;

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

  { Create device object }
  a := TBrickletAccelerometer.Create(UID, ipcon);

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

  { Register acceleration callback to procedure AccelerationCB }
  a.OnAcceleration := {$ifdef FPC}@{$endif}AccelerationCB;

  { Set period for acceleration callback to 1s (1000ms)
    Note: The acceleration callback is only called every second
          if the acceleration has changed since the last call! }
  a.SetAccelerationCallbackPeriod(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, BrickletAccelerometer;

type
  TExample = class
  private
    ipcon: TIPConnection;
    a: TBrickletAccelerometer;
  public
    procedure AccelerationReachedCB(sender: TBrickletAccelerometer; const x: smallint;
                                    const y: smallint; const z: smallint);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for acceleration reached callback }
procedure TExample.AccelerationReachedCB(sender: TBrickletAccelerometer;
                                         const x: smallint; const y: smallint;
                                         const z: smallint);
begin
  WriteLn(Format('Acceleration [X]: %f g', [x/1000.0]));
  WriteLn(Format('Acceleration [Y]: %f g', [y/1000.0]));
  WriteLn(Format('Acceleration [Z]: %f g', [z/1000.0]));
  WriteLn('');
end;

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

  { Create device object }
  a := TBrickletAccelerometer.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) }
  a.SetDebouncePeriod(10000);

  { Register acceleration reached callback to procedure AccelerationReachedCB }
  a.OnAccelerationReached := {$ifdef FPC}@{$endif}AccelerationReachedCB;

  { Configure threshold for acceleration "greater than 2 g, 2 g, 2 g" }
  a.SetAccelerationCallbackThreshold('>', 2*1000, 0, 2*1000, 0, 2*1000, 0);

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

Parameters:	uid – Type: string ipcon – Type: TIPConnection
Returns:	accelerometer – Type: TBrickletAccelerometer

Creates an object with the unique device ID uid:

accelerometer := TBrickletAccelerometer.Create('YOUR_DEVICE_UID', ipcon);

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

procedure TBrickletAccelerometer.GetAcceleration(out x: smallint; out y: smallint; out z: smallint)¶

Output Parameters:	x – Type: smallint, Unit: 1/1000 gₙ, Range: ? y – Type: smallint, Unit: 1/1000 gₙ, Range: ? z – Type: smallint, Unit: 1/1000 gₙ, Range: ?

Returns the acceleration in x, y and z direction. The values are given in gₙ/1000 (1gₙ = 9.80665m/s²). The range is configured with SetConfiguration.

If you want to get the acceleration periodically, it is recommended to use the OnAcceleration callback and set the period with SetAccelerationCallbackPeriod.

function TBrickletAccelerometer.GetTemperature: smallint¶

Returns:	temperature – Type: smallint, Unit: 1 °C, Range: [-103 to 152]

Returns the temperature of the accelerometer.

procedure TBrickletAccelerometer.LEDOn¶

Enables the LED on the Bricklet.

procedure TBrickletAccelerometer.LEDOff¶

Disables the LED on the Bricklet.

function TBrickletAccelerometer.IsLEDOn: boolean¶

Returns:	on – Type: boolean, Default: false

Returns true if the LED is enabled, false otherwise.

Advanced Functions¶

procedure TBrickletAccelerometer.SetConfiguration(const dataRate: byte; const fullScale: byte; const filterBandwidth: byte)¶

Parameters:	dataRate – Type: byte, Range: See constants, Default: 6 fullScale – Type: byte, Range: See constants, Default: 1 filterBandwidth – Type: byte, Range: See constants, Default: 2

Configures the data rate, full scale range and filter bandwidth. Possible values are:

• Data rate of 0Hz to 1600Hz.
• Full scale range of ±2gₙ up to ±16gₙ.
• Filter bandwidth between 50Hz and 800Hz.

Decreasing data rate or full scale range will also decrease the noise on the data.

The following constants are available for this function:

For dataRate:

• BRICKLET_ACCELEROMETER_DATA_RATE_OFF = 0
• BRICKLET_ACCELEROMETER_DATA_RATE_3HZ = 1
• BRICKLET_ACCELEROMETER_DATA_RATE_6HZ = 2
• BRICKLET_ACCELEROMETER_DATA_RATE_12HZ = 3
• BRICKLET_ACCELEROMETER_DATA_RATE_25HZ = 4
• BRICKLET_ACCELEROMETER_DATA_RATE_50HZ = 5
• BRICKLET_ACCELEROMETER_DATA_RATE_100HZ = 6
• BRICKLET_ACCELEROMETER_DATA_RATE_400HZ = 7
• BRICKLET_ACCELEROMETER_DATA_RATE_800HZ = 8
• BRICKLET_ACCELEROMETER_DATA_RATE_1600HZ = 9

For fullScale:

• BRICKLET_ACCELEROMETER_FULL_SCALE_2G = 0
• BRICKLET_ACCELEROMETER_FULL_SCALE_4G = 1
• BRICKLET_ACCELEROMETER_FULL_SCALE_6G = 2
• BRICKLET_ACCELEROMETER_FULL_SCALE_8G = 3
• BRICKLET_ACCELEROMETER_FULL_SCALE_16G = 4

For filterBandwidth:

• BRICKLET_ACCELEROMETER_FILTER_BANDWIDTH_800HZ = 0
• BRICKLET_ACCELEROMETER_FILTER_BANDWIDTH_400HZ = 1
• BRICKLET_ACCELEROMETER_FILTER_BANDWIDTH_200HZ = 2
• BRICKLET_ACCELEROMETER_FILTER_BANDWIDTH_50HZ = 3

procedure TBrickletAccelerometer.GetConfiguration(out dataRate: byte; out fullScale: byte; out filterBandwidth: byte)¶

Output Parameters:	dataRate – Type: byte, Range: See constants, Default: 6 fullScale – Type: byte, Range: See constants, Default: 1 filterBandwidth – Type: byte, Range: See constants, Default: 2

Returns the configuration as set by SetConfiguration.

The following constants are available for this function:

For dataRate:

• BRICKLET_ACCELEROMETER_DATA_RATE_OFF = 0
• BRICKLET_ACCELEROMETER_DATA_RATE_3HZ = 1
• BRICKLET_ACCELEROMETER_DATA_RATE_6HZ = 2
• BRICKLET_ACCELEROMETER_DATA_RATE_12HZ = 3
• BRICKLET_ACCELEROMETER_DATA_RATE_25HZ = 4
• BRICKLET_ACCELEROMETER_DATA_RATE_50HZ = 5
• BRICKLET_ACCELEROMETER_DATA_RATE_100HZ = 6
• BRICKLET_ACCELEROMETER_DATA_RATE_400HZ = 7
• BRICKLET_ACCELEROMETER_DATA_RATE_800HZ = 8
• BRICKLET_ACCELEROMETER_DATA_RATE_1600HZ = 9

For fullScale:

• BRICKLET_ACCELEROMETER_FULL_SCALE_2G = 0
• BRICKLET_ACCELEROMETER_FULL_SCALE_4G = 1
• BRICKLET_ACCELEROMETER_FULL_SCALE_6G = 2
• BRICKLET_ACCELEROMETER_FULL_SCALE_8G = 3
• BRICKLET_ACCELEROMETER_FULL_SCALE_16G = 4

For filterBandwidth:

• BRICKLET_ACCELEROMETER_FILTER_BANDWIDTH_800HZ = 0
• BRICKLET_ACCELEROMETER_FILTER_BANDWIDTH_400HZ = 1
• BRICKLET_ACCELEROMETER_FILTER_BANDWIDTH_200HZ = 2
• BRICKLET_ACCELEROMETER_FILTER_BANDWIDTH_50HZ = 3

procedure TBrickletAccelerometer.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 TBrickletAccelerometer.SetAccelerationCallbackPeriod(const period: longword)¶

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

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

The OnAcceleration callback is only triggered if the acceleration has changed since the last triggering.

function TBrickletAccelerometer.GetAccelerationCallbackPeriod: longword¶

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

Returns the period as set by SetAccelerationCallbackPeriod.

procedure TBrickletAccelerometer.SetAccelerationCallbackThreshold(const option: char; const minX: smallint; const maxX: smallint; const minY: smallint; const maxY: smallint; const minZ: smallint; const maxZ: smallint)¶

Parameters:

option – Type: char, Range: See constants, Default: 'x' minX – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 maxX – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 minY – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 maxY – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 minZ – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 maxZ – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0

Sets the thresholds for the OnAccelerationReached callback.

The following options are possible:

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

The following constants are available for this function:

For option:

• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_OFF = 'x'
• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_OUTSIDE = 'o'
• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_INSIDE = 'i'
• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_SMALLER = '<'
• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_GREATER = '>'

procedure TBrickletAccelerometer.GetAccelerationCallbackThreshold(out option: char; out minX: smallint; out maxX: smallint; out minY: smallint; out maxY: smallint; out minZ: smallint; out maxZ: smallint)¶

Output Parameters:

option – Type: char, Range: See constants, Default: 'x' minX – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 maxX – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 minY – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 maxY – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 minZ – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0 maxZ – Type: smallint, Unit: 1/1000 gₙ, Range: [-215 to 215 - 1], Default: 0

Returns the threshold as set by SetAccelerationCallbackThreshold.

The following constants are available for this function:

For option:

• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_OFF = 'x'
• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_OUTSIDE = 'o'
• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_INSIDE = 'i'
• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_SMALLER = '<'
• BRICKLET_ACCELEROMETER_THRESHOLD_OPTION_GREATER = '>'

procedure TBrickletAccelerometer.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

• OnAccelerationReached

is triggered, if the threshold

• SetAccelerationCallbackThreshold

keeps being reached.

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

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

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

property TBrickletAccelerometer.OnAcceleration¶

procedure(sender: TBrickletAccelerometer; const x: smallint; const y: smallint; const z: smallint) of object;

Callback Parameters:	sender – Type: TBrickletAccelerometer x – Type: smallint, Unit: 1/1000 gₙ, Range: ? y – Type: smallint, Unit: 1/1000 gₙ, Range: ? z – Type: smallint, Unit: 1/1000 gₙ, Range: ?

This callback is triggered periodically with the period that is set by SetAccelerationCallbackPeriod. The parameters are the X, Y and Z acceleration. The range is configured with SetConfiguration.

The OnAcceleration callback is only triggered if the acceleration has changed since the last triggering.

property TBrickletAccelerometer.OnAccelerationReached¶

procedure(sender: TBrickletAccelerometer; const x: smallint; const y: smallint; const z: smallint) of object;

Callback Parameters:	sender – Type: TBrickletAccelerometer x – Type: smallint, Unit: 1/1000 gₙ, Range: ? y – Type: smallint, Unit: 1/1000 gₙ, Range: ? z – Type: smallint, Unit: 1/1000 gₙ, Range: ?

This callback is triggered when the threshold as set by SetAccelerationCallbackThreshold is reached. The parameters are the X, Y and Z acceleration. The range is configured with SetConfiguration.

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

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 TBrickletAccelerometer.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 TBrickletAccelerometer.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_ACCELEROMETER_FUNCTION_SET_ACCELERATION_CALLBACK_PERIOD = 2
• BRICKLET_ACCELEROMETER_FUNCTION_SET_ACCELERATION_CALLBACK_THRESHOLD = 4
• BRICKLET_ACCELEROMETER_FUNCTION_SET_DEBOUNCE_PERIOD = 6
• BRICKLET_ACCELEROMETER_FUNCTION_SET_CONFIGURATION = 9
• BRICKLET_ACCELEROMETER_FUNCTION_LED_ON = 11
• BRICKLET_ACCELEROMETER_FUNCTION_LED_OFF = 12

procedure TBrickletAccelerometer.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_ACCELEROMETER_FUNCTION_SET_ACCELERATION_CALLBACK_PERIOD = 2
• BRICKLET_ACCELEROMETER_FUNCTION_SET_ACCELERATION_CALLBACK_THRESHOLD = 4
• BRICKLET_ACCELEROMETER_FUNCTION_SET_DEBOUNCE_PERIOD = 6
• BRICKLET_ACCELEROMETER_FUNCTION_SET_CONFIGURATION = 9
• BRICKLET_ACCELEROMETER_FUNCTION_LED_ON = 11
• BRICKLET_ACCELEROMETER_FUNCTION_LED_OFF = 12

procedure TBrickletAccelerometer.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_ACCELEROMETER_DEVICE_IDENTIFIER¶

This constant is used to identify a Accelerometer 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_ACCELEROMETER_DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a Accelerometer Bricklet.