Delphi/Lazarus - Piezo Speaker Bricklet 2.0

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

Alarm

Download (ExampleAlarm.pas)

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program ExampleAlarm;

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

uses
  SysUtils, IPConnection, BrickletPiezoSpeakerV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    ps: TBrickletPiezoSpeakerV2;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

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

  { Create device object }
  ps := TBrickletPiezoSpeakerV2.Create(UID, ipcon);

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

  { 10 seconds of loud annoying fast alarm }
  ps.SetAlarm(800, 2000, 10, 1, 10, 10000);

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

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

Beep

Download (ExampleBeep.pas)

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program ExampleBeep;

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

uses
  SysUtils, IPConnection, BrickletPiezoSpeakerV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    ps: TBrickletPiezoSpeakerV2;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

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

  { Create device object }
  ps := TBrickletPiezoSpeakerV2.Create(UID, ipcon);

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

  { Make 2 second beep with a frequency of 1kHz }
  ps.SetBeep(1000, 0, 2000);

  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 TBrickletPiezoSpeakerV2.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

piezoSpeakerV2 := TBrickletPiezoSpeakerV2.Create('YOUR_DEVICE_UID', ipcon);

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

procedure TBrickletPiezoSpeakerV2.SetBeep(const frequency: word; const volume: byte; const duration: longword)

Beeps with the given frequency and volume for the duration in ms.

For example: If you set a duration of 1000, with a volume of 10 and a frequency value of 2000 the piezo buzzer will beep with maximum loudness for one second with a frequency of 2 kHz.

A duration of 0 stops the current beep if any is ongoing. A duration of 4294967295 results in an infinite beep.

The ranges are:

  • Frequency: 50Hz - 15000Hz
  • Volume: 0 - 10
  • Duration: 0ms - 4294967295ms

The following constants are available for this function:

  • BRICKLET_PIEZO_SPEAKER_V2_BEEP_DURATION_OFF = 0
  • BRICKLET_PIEZO_SPEAKER_V2_BEEP_DURATION_INFINITE = 4294967295
procedure TBrickletPiezoSpeakerV2.GetBeep(out frequency: word; out volume: byte; out duration: longword; out durationRemaining: longword)

Returns the last beep settings as set by SetBeep. If a beep is currently running it also returns the remaining duration of the beep in ms.

If the frequency or volume is updated during a beep (with UpdateFrequency or UpdateVolume) this function returns the updated value.

The following constants are available for this function:

  • BRICKLET_PIEZO_SPEAKER_V2_BEEP_DURATION_OFF = 0
  • BRICKLET_PIEZO_SPEAKER_V2_BEEP_DURATION_INFINITE = 4294967295
procedure TBrickletPiezoSpeakerV2.SetAlarm(const startFrequency: word; const endFrequency: word; const stepSize: word; const stepDelay: word; const volume: byte; const duration: longword)

Creates an alarm (a tone that goes back and force between two specified frequencies).

The following parameters can be set:

  • Start Frequency: Start frequency of the alarm in Hz.
  • End Frequency: End frequency of the alarm in Hz.
  • Step Size: Size of one step of the sweep between the start/end frequencies in Hz.
  • Step Delay: Delay between two steps (duration of time that one tone is used in a sweep) in ms.
  • Duration: Duration of the alarm in ms.

A duration of 0 stops the current alarm if any is ongoing. A duration of 4294967295 results in an infinite alarm.

Below you can find two sets of example settings that you can try out. You can use these as a starting point to find an alarm signal that suits your application.

Example 1: 10 seconds of loud annoying fast alarm

  • Start Frequency = 800
  • End Frequency = 2000
  • Step Size = 10
  • Step Delay = 1
  • Volume = 10
  • Duration = 10000

Example 2: 10 seconds of soft siren sound with slow build-up

  • Start Frequency = 250
  • End Frequency = 750
  • Step Size = 1
  • Step Delay = 5
  • Volume = 0
  • Duration = 10000

The ranges are:

  • Start Frequency: 50Hz - 14999Hz (has to be smaller than end frequency)
  • End Frequency: 51Hz - 15000Hz (has to be bigger than start frequency)
  • Step Size: 1Hz - 65535Hz (has to be small enough to fit into the frequency range)
  • Step Delay: 1ms - 65535ms (has to be small enough to fit into the duration)
  • Volume: 0 - 10
  • Duration: 0ms - 4294967295ms

The following constants are available for this function:

  • BRICKLET_PIEZO_SPEAKER_V2_ALARM_DURATION_OFF = 0
  • BRICKLET_PIEZO_SPEAKER_V2_ALARM_DURATION_INFINITE = 4294967295
procedure TBrickletPiezoSpeakerV2.GetAlarm(out startFrequency: word; out endFrequency: word; out stepSize: word; out stepDelay: word; out volume: byte; out duration: longword; out durationRemaining: longword; out currentFrequency: word)

Returns the last alarm settings as set by SetAlarm. If an alarm is currently running it also returns the remaining duration of the alarm in ms as well as the current frequency of the alarm in Hz.

If the volume is updated during a beep (with UpdateVolume) this function returns the updated value.

The following constants are available for this function:

  • BRICKLET_PIEZO_SPEAKER_V2_ALARM_DURATION_OFF = 0
  • BRICKLET_PIEZO_SPEAKER_V2_ALARM_DURATION_INFINITE = 4294967295
procedure TBrickletPiezoSpeakerV2.UpdateVolume(const volume: byte)

Updates the volume of an ongoing beep or alarm. The range of the volume is 0 to 10.

procedure TBrickletPiezoSpeakerV2.UpdateFrequency(const frequency: word)

Updates the frequency of an ongoing beep. The range of the frequency is 50Hz to 15000Hz.

Advanced Functions

function TBrickletPiezoSpeakerV2.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 TBrickletPiezoSpeakerV2.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 TBrickletPiezoSpeakerV2.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_PIEZO_SPEAKER_V2_FUNCTION_SET_BEEP = 1
  • BRICKLET_PIEZO_SPEAKER_V2_FUNCTION_SET_ALARM = 3
  • BRICKLET_PIEZO_SPEAKER_V2_FUNCTION_UPDATE_VOLUME = 5
  • BRICKLET_PIEZO_SPEAKER_V2_FUNCTION_UPDATE_FREQUENCY = 6
  • BRICKLET_PIEZO_SPEAKER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_PIEZO_SPEAKER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_PIEZO_SPEAKER_V2_FUNCTION_RESET = 243
  • BRICKLET_PIEZO_SPEAKER_V2_FUNCTION_WRITE_UID = 248
procedure TBrickletPiezoSpeakerV2.SetResponseExpectedAll(const responseExpected: boolean)

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

procedure TBrickletPiezoSpeakerV2.GetSPITFPErrorCount(out errorCountAckChecksum: longword; out errorCountMessageChecksum: longword; out errorCountFrame: longword; out errorCountOverflow: longword)

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 TBrickletPiezoSpeakerV2.SetBootloaderMode(const mode: byte): byte

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:

  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_OK = 0
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
function TBrickletPiezoSpeakerV2.GetBootloaderMode: byte

Returns the current bootloader mode, see SetBootloaderMode.

The following constants are available for this function:

  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
procedure TBrickletPiezoSpeakerV2.SetWriteFirmwarePointer(const pointer: longword)

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 TBrickletPiezoSpeakerV2.WriteFirmware(const data: array [0..63] of byte): byte

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 TBrickletPiezoSpeakerV2.SetStatusLEDConfig(const config: byte)

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:

  • BRICKLET_PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletPiezoSpeakerV2.GetStatusLEDConfig: byte

Returns the configuration as set by SetStatusLEDConfig

The following constants are available for this function:

  • BRICKLET_PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletPiezoSpeakerV2.GetChipTemperature: smallint

Returns the temperature in °C 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 TBrickletPiezoSpeakerV2.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 TBrickletPiezoSpeakerV2.WriteUID(const uid: longword)

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 TBrickletPiezoSpeakerV2.ReadUID: longword

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

procedure TBrickletPiezoSpeakerV2.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.

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: TBrickletPiezoSpeakerV2; const param: word);
begin
  WriteLn(param);
end;

piezoSpeakerV2.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 TBrickletPiezoSpeakerV2.OnBeepFinished
procedure(sender: TBrickletPiezoSpeakerV2) of object;

This callback is triggered if a beep set by SetBeep is finished

property TBrickletPiezoSpeakerV2.OnAlarmFinished
procedure(sender: TBrickletPiezoSpeakerV2) of object;

This callback is triggered if a alarm set by SetAlarm is finished

Constants

const BRICKLET_PIEZO_SPEAKER_V2_DEVICE_IDENTIFIER

This constant is used to identify a Piezo Speaker 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_PIEZO_SPEAKER_V2_DEVICE_DISPLAY_NAME

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