Delphi/Lazarus - Accelerometer Bricklet 2.0

This is the description of the Delphi/Lazarus API bindings for the Accelerometer Bricklet 2.0. General information and technical specifications for the Accelerometer 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, BrickletAccelerometerV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    a: TBrickletAccelerometerV2;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

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

  { Create device object }
  a := TBrickletAccelerometerV2.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/10000.0]));
  WriteLn(Format('Acceleration [Y]: %f g', [y/10000.0]));
  WriteLn(Format('Acceleration [Z]: %f g', [z/10000.0]));

  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, BrickletAccelerometerV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    a: TBrickletAccelerometerV2;
  public
    procedure AccelerationCB(sender: TBrickletAccelerometerV2; const x: longint;
                             const y: longint; const z: longint);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for acceleration callback }
procedure TExample.AccelerationCB(sender: TBrickletAccelerometerV2; const x: longint;
                                  const y: longint; const z: longint);
begin
  WriteLn(Format('Acceleration [X]: %f g', [x/10000.0]));
  WriteLn(Format('Acceleration [Y]: %f g', [y/10000.0]));
  WriteLn(Format('Acceleration [Z]: %f g', [z/10000.0]));
  WriteLn('');
end;

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

  { Create device object }
  a := TBrickletAccelerometerV2.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) }
  a.SetAccelerationCallbackConfiguration(1000, false);

  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 TBrickletAccelerometerV2.Create(const uid: string; ipcon: TIPConnection)
Parameters:
  • uid – Type: string
  • ipcon – Type: TIPConnection
Returns:
  • accelerometerV2 – Type: TBrickletAccelerometerV2

Creates an object with the unique device ID uid:

accelerometerV2 := TBrickletAccelerometerV2.Create('YOUR_DEVICE_UID', ipcon);

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

procedure TBrickletAccelerometerV2.GetAcceleration(out x: longint; out y: longint; out z: longint)
Output Parameters:
  • x – Type: longint, Unit: 1/10000 gₙ, Range: ?
  • y – Type: longint, Unit: 1/10000 gₙ, Range: ?
  • z – Type: longint, Unit: 1/10000 gₙ, Range: ?

Returns the acceleration in x, y and z direction. The values are given in gₙ/10000 (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 SetAccelerationCallbackConfiguration.

procedure TBrickletAccelerometerV2.SetConfiguration(const dataRate: byte; const fullScale: byte)
Parameters:
  • dataRate – Type: byte, Range: See constants, Default: 7
  • fullScale – Type: byte, Range: See constants, Default: 0

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

  • Data rate of 0.781Hz to 25600Hz.
  • Full scale range of ±2g up to ±8g.

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_V2_DATA_RATE_0_781HZ = 0
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_1_563HZ = 1
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_3_125HZ = 2
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_6_2512HZ = 3
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_12_5HZ = 4
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_25HZ = 5
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_50HZ = 6
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_100HZ = 7
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_200HZ = 8
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_400HZ = 9
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_800HZ = 10
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_1600HZ = 11
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_3200HZ = 12
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_6400HZ = 13
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_12800HZ = 14
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_25600HZ = 15

For fullScale:

  • BRICKLET_ACCELEROMETER_V2_FULL_SCALE_2G = 0
  • BRICKLET_ACCELEROMETER_V2_FULL_SCALE_4G = 1
  • BRICKLET_ACCELEROMETER_V2_FULL_SCALE_8G = 2
procedure TBrickletAccelerometerV2.GetConfiguration(out dataRate: byte; out fullScale: byte)
Output Parameters:
  • dataRate – Type: byte, Range: See constants, Default: 7
  • fullScale – Type: byte, Range: See constants, Default: 0

Returns the configuration as set by SetConfiguration.

The following constants are available for this function:

For dataRate:

  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_0_781HZ = 0
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_1_563HZ = 1
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_3_125HZ = 2
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_6_2512HZ = 3
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_12_5HZ = 4
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_25HZ = 5
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_50HZ = 6
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_100HZ = 7
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_200HZ = 8
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_400HZ = 9
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_800HZ = 10
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_1600HZ = 11
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_3200HZ = 12
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_6400HZ = 13
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_12800HZ = 14
  • BRICKLET_ACCELEROMETER_V2_DATA_RATE_25600HZ = 15

For fullScale:

  • BRICKLET_ACCELEROMETER_V2_FULL_SCALE_2G = 0
  • BRICKLET_ACCELEROMETER_V2_FULL_SCALE_4G = 1
  • BRICKLET_ACCELEROMETER_V2_FULL_SCALE_8G = 2
procedure TBrickletAccelerometerV2.SetInfoLEDConfig(const config: byte)
Parameters:
  • config – Type: byte, Range: See constants, Default: 0

Configures the info LED (marked as "Force" on the Bricklet) to be either turned off, turned on, or blink in heartbeat mode.

The following constants are available for this function:

For config:

  • BRICKLET_ACCELEROMETER_V2_INFO_LED_CONFIG_OFF = 0
  • BRICKLET_ACCELEROMETER_V2_INFO_LED_CONFIG_ON = 1
  • BRICKLET_ACCELEROMETER_V2_INFO_LED_CONFIG_SHOW_HEARTBEAT = 2
function TBrickletAccelerometerV2.GetInfoLEDConfig: byte
Returns:
  • config – Type: byte, Range: See constants, Default: 0

Returns the LED configuration as set by SetInfoLEDConfig

The following constants are available for this function:

For config:

  • BRICKLET_ACCELEROMETER_V2_INFO_LED_CONFIG_OFF = 0
  • BRICKLET_ACCELEROMETER_V2_INFO_LED_CONFIG_ON = 1
  • BRICKLET_ACCELEROMETER_V2_INFO_LED_CONFIG_SHOW_HEARTBEAT = 2
procedure TBrickletAccelerometerV2.SetContinuousAccelerationConfiguration(const enableX: boolean; const enableY: boolean; const enableZ: boolean; const resolution: byte)
Parameters:
  • enableX – Type: boolean, Default: false
  • enableY – Type: boolean, Default: false
  • enableZ – Type: boolean, Default: false
  • resolution – Type: byte, Range: See constants, Default: 0

For high throughput of acceleration data (> 1000Hz) you have to use the OnContinuousAcceleration16Bit or OnContinuousAcceleration8Bit callbacks.

You can enable the callback for each axis (x, y, z) individually and choose a resolution of 8 bit or 16 bit.

If at least one of the axis is enabled and the resolution is set to 8 bit, the OnContinuousAcceleration8Bit callback is activated. If at least one of the axis is enabled and the resolution is set to 16 bit, the OnContinuousAcceleration16Bit callback is activated.

The returned values are raw ADC data. If you want to put this data into a FFT to determine the occurrences of specific frequencies we recommend that you use the data as is. It has all of the ADC noise in it. This noise looks like pure noise at first glance, but it might still have some frequnecy information in it that can be utilized by the FFT.

Otherwise you have to use the following formulas that depend on the configured resolution (8/16 bit) and the full scale range (see SetConfiguration) to calculate the data in gₙ/10000 (same unit that is returned by GetAcceleration):

  • 16 bit, full scale 2g: acceleration = value * 625 / 1024
  • 16 bit, full scale 4g: acceleration = value * 1250 / 1024
  • 16 bit, full scale 8g: acceleration = value * 2500 / 1024

If a resolution of 8 bit is used, only the 8 most significant bits will be transferred, so you can use the following formulas:

  • 8 bit, full scale 2g: acceleration = value * 256 * 625 / 1024
  • 8 bit, full scale 4g: acceleration = value * 256 * 1250 / 1024
  • 8 bit, full scale 8g: acceleration = value * 256 * 2500 / 1024

If no axis is enabled, both callbacks are disabled. If one of the continuous callbacks is enabled, the OnAcceleration callback is disabled.

The maximum throughput depends on the exact configuration:

Number of axis enabled Throughput 8 bit Throughout 16 bit
1 25600Hz 25600Hz
2 25600Hz 15000Hz
3 20000Hz 10000Hz

The following constants are available for this function:

For resolution:

  • BRICKLET_ACCELEROMETER_V2_RESOLUTION_8BIT = 0
  • BRICKLET_ACCELEROMETER_V2_RESOLUTION_16BIT = 1
procedure TBrickletAccelerometerV2.GetContinuousAccelerationConfiguration(out enableX: boolean; out enableY: boolean; out enableZ: boolean; out resolution: byte)
Output Parameters:
  • enableX – Type: boolean, Default: false
  • enableY – Type: boolean, Default: false
  • enableZ – Type: boolean, Default: false
  • resolution – Type: byte, Range: See constants, Default: 0

Returns the continuous acceleration configuration as set by SetContinuousAccelerationConfiguration.

The following constants are available for this function:

For resolution:

  • BRICKLET_ACCELEROMETER_V2_RESOLUTION_8BIT = 0
  • BRICKLET_ACCELEROMETER_V2_RESOLUTION_16BIT = 1

Advanced Functions

procedure TBrickletAccelerometerV2.SetFilterConfiguration(const iirBypass: byte; const lowPassFilter: byte)
Parameters:
  • iirBypass – Type: byte, Range: See constants, Default: 0
  • lowPassFilter – Type: byte, Range: See constants, Default: 0

Configures IIR Bypass filter mode and low pass filter roll off corner frequency.

The filter can be applied or bypassed and the corner frequency can be half or a ninth of the output data rate.

Accelerometer filter

The following constants are available for this function:

For iirBypass:

  • BRICKLET_ACCELEROMETER_V2_IIR_BYPASS_APPLIED = 0
  • BRICKLET_ACCELEROMETER_V2_IIR_BYPASS_BYPASSED = 1

For lowPassFilter:

  • BRICKLET_ACCELEROMETER_V2_LOW_PASS_FILTER_NINTH = 0
  • BRICKLET_ACCELEROMETER_V2_LOW_PASS_FILTER_HALF = 1

New in version 2.0.2 (Plugin).

procedure TBrickletAccelerometerV2.GetFilterConfiguration(out iirBypass: byte; out lowPassFilter: byte)
Output Parameters:
  • iirBypass – Type: byte, Range: See constants, Default: 0
  • lowPassFilter – Type: byte, Range: See constants, Default: 0

Returns the configuration as set by SetFilterConfiguration.

The following constants are available for this function:

For iirBypass:

  • BRICKLET_ACCELEROMETER_V2_IIR_BYPASS_APPLIED = 0
  • BRICKLET_ACCELEROMETER_V2_IIR_BYPASS_BYPASSED = 1

For lowPassFilter:

  • BRICKLET_ACCELEROMETER_V2_LOW_PASS_FILTER_NINTH = 0
  • BRICKLET_ACCELEROMETER_V2_LOW_PASS_FILTER_HALF = 1

New in version 2.0.2 (Plugin).

procedure TBrickletAccelerometerV2.GetSPITFPErrorCount(out errorCountAckChecksum: longword; out errorCountMessageChecksum: longword; out errorCountFrame: longword; out errorCountOverflow: longword)
Output Parameters:
  • errorCountAckChecksum – Type: longword, Range: [0 to 232 - 1]
  • errorCountMessageChecksum – Type: longword, Range: [0 to 232 - 1]
  • errorCountFrame – Type: longword, Range: [0 to 232 - 1]
  • errorCountOverflow – Type: longword, Range: [0 to 232 - 1]

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

function TBrickletAccelerometerV2.SetBootloaderMode(const mode: byte): byte
Parameters:
  • mode – Type: byte, Range: See constants
Returns:
  • status – Type: byte, Range: See constants

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

For mode:

  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For status:

  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_STATUS_OK = 0
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
function TBrickletAccelerometerV2.GetBootloaderMode: byte
Returns:
  • mode – Type: byte, Range: See constants

Returns the current bootloader mode, see SetBootloaderMode.

The following constants are available for this function:

For mode:

  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
procedure TBrickletAccelerometerV2.SetWriteFirmwarePointer(const pointer: longword)
Parameters:
  • pointer – Type: longword, Unit: 1 B, Range: [0 to 232 - 1]

Sets the firmware pointer for WriteFirmware. The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

function TBrickletAccelerometerV2.WriteFirmware(const data: array [0..63] of byte): byte
Parameters:
  • data – Type: array [0..63] of byte, Range: [0 to 255]
Returns:
  • status – Type: byte, Range: [0 to 255]

Writes 64 Bytes of firmware at the position as written by SetWriteFirmwarePointer before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

procedure TBrickletAccelerometerV2.SetStatusLEDConfig(const config: byte)
Parameters:
  • config – Type: byte, Range: See constants, Default: 3

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

For config:

  • BRICKLET_ACCELEROMETER_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_ACCELEROMETER_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_ACCELEROMETER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_ACCELEROMETER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletAccelerometerV2.GetStatusLEDConfig: byte
Returns:
  • config – Type: byte, Range: See constants, Default: 3

Returns the configuration as set by SetStatusLEDConfig

The following constants are available for this function:

For config:

  • BRICKLET_ACCELEROMETER_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_ACCELEROMETER_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_ACCELEROMETER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_ACCELEROMETER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletAccelerometerV2.GetChipTemperature: smallint
Returns:
  • temperature – Type: smallint, Unit: 1 °C, Range: [-215 to 215 - 1]

Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

procedure TBrickletAccelerometerV2.Reset

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

procedure TBrickletAccelerometerV2.WriteUID(const uid: longword)
Parameters:
  • uid – Type: longword, Range: [0 to 232 - 1]

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

function TBrickletAccelerometerV2.ReadUID: longword
Returns:
  • uid – Type: longword, Range: [0 to 232 - 1]

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

procedure TBrickletAccelerometerV2.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', 'i', '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). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as 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 TBrickletAccelerometerV2.SetAccelerationCallbackConfiguration(const period: longword; const valueHasToChange: boolean)
Parameters:
  • period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false

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

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

If this callback is enabled, the OnContinuousAcceleration16Bit callback and OnContinuousAcceleration8Bit callback will automatically be disabled.

procedure TBrickletAccelerometerV2.GetAccelerationCallbackConfiguration(out period: longword; out valueHasToChange: boolean)
Output Parameters:
  • period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false

Returns the callback configuration as set by SetAccelerationCallbackConfiguration.

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: TBrickletAccelerometerV2; const value: longint);
begin
  WriteLn(Format('Value: %d', [value]));
end;

accelerometerV2.OnExample := {$ifdef FPC}@{$endif}example.MyCallback;

The available callback properties and their parameter types 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 TBrickletAccelerometerV2.OnAcceleration
procedure(sender: TBrickletAccelerometerV2; const x: longint; const y: longint; const z: longint) of object;
Callback Parameters:
  • sender – Type: TBrickletAccelerometerV2
  • x – Type: longint, Unit: 1/10000 gₙ, Range: ?
  • y – Type: longint, Unit: 1/10000 gₙ, Range: ?
  • z – Type: longint, Unit: 1/10000 gₙ, Range: ?

This callback is triggered periodically according to the configuration set by SetAccelerationCallbackConfiguration.

The parameters are the same as GetAcceleration.

property TBrickletAccelerometerV2.OnContinuousAcceleration16Bit
procedure(sender: TBrickletAccelerometerV2; const acceleration: array [0..29] of smallint) of object;
Callback Parameters:
  • sender – Type: TBrickletAccelerometerV2
  • acceleration – Type: array [0..29] of smallint, Unit: ? gₙ, Range: ?

Returns 30 acceleration values with 16 bit resolution. The data rate can be configured with SetConfiguration and this callback can be enabled with SetContinuousAccelerationConfiguration.

The returned values are raw ADC data. If you want to put this data into a FFT to determine the occurrences of specific frequencies we recommend that you use the data as is. It has all of the ADC noise in it. This noise looks like pure noise at first glance, but it might still have some frequnecy information in it that can be utilized by the FFT.

Otherwise you have to use the following formulas that depend on the full scale range (see SetConfiguration) to calculate the data in gₙ/10000 (same unit that is returned by GetAcceleration):

  • Full scale 2g: acceleration = value * 625 / 1024
  • Full scale 4g: acceleration = value * 1250 / 1024
  • Full scale 8g: acceleration = value * 2500 / 1024

The data is formated in the sequence "x, y, z, x, y, z, ..." depending on the enabled axis. Examples:

  • x, y, z enabled: "x, y, z, ..." 10x repeated
  • x, z enabled: "x, z, ..." 15x repeated
  • y enabled: "y, ..." 30x repeated
property TBrickletAccelerometerV2.OnContinuousAcceleration8Bit
procedure(sender: TBrickletAccelerometerV2; const acceleration: array [0..59] of shortint) of object;
Callback Parameters:
  • sender – Type: TBrickletAccelerometerV2
  • acceleration – Type: array [0..59] of shortint, Unit: ? gₙ, Range: ?

Returns 60 acceleration values with 8 bit resolution. The data rate can be configured with SetConfiguration and this callback can be enabled with SetContinuousAccelerationConfiguration.

The returned values are raw ADC data. If you want to put this data into a FFT to determine the occurrences of specific frequencies we recommend that you use the data as is. It has all of the ADC noise in it. This noise looks like pure noise at first glance, but it might still have some frequnecy information in it that can be utilized by the FFT.

Otherwise you have to use the following formulas that depend on the full scale range (see SetConfiguration) to calculate the data in gₙ/10000 (same unit that is returned by GetAcceleration):

  • Full scale 2g: acceleration = value * 256 * 625 / 1024
  • Full scale 4g: acceleration = value * 256 * 1250 / 1024
  • Full scale 8g: acceleration = value * 256 * 2500 / 1024

The data is formated in the sequence "x, y, z, x, y, z, ..." depending on the enabled axis. Examples:

  • x, y, z enabled: "x, y, z, ..." 20x repeated
  • x, z enabled: "x, z, ..." 30x repeated
  • y enabled: "y, ..." 60x repeated

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 TBrickletAccelerometerV2.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 TBrickletAccelerometerV2.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 send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_CONFIGURATION = 2
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_ACCELERATION_CALLBACK_CONFIGURATION = 4
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_INFO_LED_CONFIG = 6
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_CONTINUOUS_ACCELERATION_CONFIGURATION = 9
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_FILTER_CONFIGURATION = 13
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_RESET = 243
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_WRITE_UID = 248
procedure TBrickletAccelerometerV2.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 send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_CONFIGURATION = 2
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_ACCELERATION_CALLBACK_CONFIGURATION = 4
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_INFO_LED_CONFIG = 6
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_CONTINUOUS_ACCELERATION_CONFIGURATION = 9
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_FILTER_CONFIGURATION = 13
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_RESET = 243
  • BRICKLET_ACCELEROMETER_V2_FUNCTION_WRITE_UID = 248
procedure TBrickletAccelerometerV2.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_V2_DEVICE_IDENTIFIER

This constant is used to identify a Accelerometer Bricklet 2.0.

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_V2_DEVICE_DISPLAY_NAME

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