Delphi/Lazarus - Air Quality Bricklet

This is the description of the Delphi/Lazarus API bindings for the Air Quality Bricklet. General information and technical specifications for the Air Quality Bricklet 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, BrickletAirQuality;

type
  TExample = class
  private
    ipcon: TIPConnection;
    aq: TBrickletAirQuality;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

procedure TExample.Execute;
var iaqIndex, temperature, humidity, airPressure: longint; iaqIndexAccuracy: byte;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  aq := TBrickletAirQuality.Create(UID, ipcon);

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

  { Get current all values }
  aq.GetAllValues(iaqIndex, iaqIndexAccuracy, temperature, humidity, airPressure);

  WriteLn(Format('IAQ Index: %d', [iaqIndex]));

  if (iaqIndexAccuracy = BRICKLET_AIR_QUALITY_ACCURACY_UNRELIABLE) then begin
    WriteLn('IAQ Index Accuracy: Unreliable');
  end
  else if (iaqIndexAccuracy = BRICKLET_AIR_QUALITY_ACCURACY_LOW) then begin
    WriteLn('IAQ Index Accuracy: Low');
  end
  else if (iaqIndexAccuracy = BRICKLET_AIR_QUALITY_ACCURACY_MEDIUM) then begin
    WriteLn('IAQ Index Accuracy: Medium');
  end
  else if (iaqIndexAccuracy = BRICKLET_AIR_QUALITY_ACCURACY_HIGH) then begin
    WriteLn('IAQ Index Accuracy: High');
  end;

  WriteLn(Format('Temperature: %f °C', [temperature/100.0]));
  WriteLn(Format('Humidity: %f %%RH', [humidity/100.0]));
  WriteLn(Format('Air Pressure: %f mbar', [airPressure/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, BrickletAirQuality;

type
  TExample = class
  private
    ipcon: TIPConnection;
    aq: TBrickletAirQuality;
  public
    procedure AllValuesCB(sender: TBrickletAirQuality; const iaqIndex: longint;
                          const iaqIndexAccuracy: byte; const temperature: longint;
                          const humidity: longint; const airPressure: longint);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for all values callback }
procedure TExample.AllValuesCB(sender: TBrickletAirQuality; const iaqIndex: longint;
                               const iaqIndexAccuracy: byte; const temperature: longint;
                               const humidity: longint; const airPressure: longint);
begin
  WriteLn(Format('IAQ Index: %d', [iaqIndex]));

  if (iaqIndexAccuracy = BRICKLET_AIR_QUALITY_ACCURACY_UNRELIABLE) then begin
    WriteLn('IAQ Index Accuracy: Unreliable');
  end
  else if (iaqIndexAccuracy = BRICKLET_AIR_QUALITY_ACCURACY_LOW) then begin
    WriteLn('IAQ Index Accuracy: Low');
  end
  else if (iaqIndexAccuracy = BRICKLET_AIR_QUALITY_ACCURACY_MEDIUM) then begin
    WriteLn('IAQ Index Accuracy: Medium');
  end
  else if (iaqIndexAccuracy = BRICKLET_AIR_QUALITY_ACCURACY_HIGH) then begin
    WriteLn('IAQ Index Accuracy: High');
  end;

  WriteLn(Format('Temperature: %f °C', [temperature/100.0]));
  WriteLn(Format('Humidity: %f %%RH', [humidity/100.0]));
  WriteLn(Format('Air Pressure: %f mbar', [airPressure/100.0]));
  WriteLn('');
end;

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

  { Create device object }
  aq := TBrickletAirQuality.Create(UID, ipcon);

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

  { Register all values callback to procedure AllValuesCB }
  aq.OnAllValues := {$ifdef FPC}@{$endif}AllValuesCB;

  { Set period for all values callback to 1s (1000ms) }
  aq.SetAllValuesCallbackConfiguration(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 TBrickletAirQuality.Create(const uid: string; ipcon: TIPConnection)
Parameters:
  • uid – Type: string
  • ipcon – Type: TIPConnection
Returns:
  • airQuality – Type: TBrickletAirQuality

Creates an object with the unique device ID uid:

airQuality := TBrickletAirQuality.Create('YOUR_DEVICE_UID', ipcon);

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

procedure TBrickletAirQuality.GetAllValues(out iaqIndex: longint; out iaqIndexAccuracy: byte; out temperature: longint; out humidity: longint; out airPressure: longint)
Output Parameters:
  • iaqIndex – Type: longint, Range: [-231 to 231 - 1]
  • iaqIndexAccuracy – Type: byte, Range: See constants
  • temperature – Type: longint, Range: [-231 to 231 - 1]
  • humidity – Type: longint, Range: [-231 to 231 - 1]
  • airPressure – Type: longint, Range: [-231 to 231 - 1]

Returns all values measured by the Air Quality Bricklet. The values are IAQ (Indoor Air Quality) Index, IAQ Index Accuracy, Temperature, Humidity and Air Pressure.

Air Quality Index description

The values have these ranges and units:

  • IAQ Index: 0 to 500, higher value means greater level of air pollution
  • IAQ Index Accuracy: 0 = unreliable to 3 = high
  • Temperature: in steps of 0.01 °C
  • Humidity: in steps of 0.01 %RH
  • Air Pressure: in steps of 0.01 mbar

The following constants are available for this function:

For iaqIndexAccuracy:

  • BRICKLET_AIR_QUALITY_ACCURACY_UNRELIABLE = 0
  • BRICKLET_AIR_QUALITY_ACCURACY_LOW = 1
  • BRICKLET_AIR_QUALITY_ACCURACY_MEDIUM = 2
  • BRICKLET_AIR_QUALITY_ACCURACY_HIGH = 3
procedure TBrickletAirQuality.SetTemperatureOffset(const offset: longint)
Parameters:
  • offset – Type: longint, Range: [-231 to 231 - 1]

Sets a temperature offset with resolution 1/100°C. A offset of 10 will decrease the measured temperature by 0.1°C.

If you install this Bricklet into an enclosure and you want to measure the ambient temperature, you may have to decrease the measured temperature by some value to compensate for the error because of the heating inside of the enclosure.

We recommend that you leave the parts in the enclosure running for at least 24 hours such that a temperature equilibrium can be reached. After that you can measure the temperature directly outside of enclosure and set the difference as offset.

This temperature offset is used to calculate the relative humidity and IAQ index measurements. In case the Bricklet is installed in an enclosure, we recommend to measure and set the temperature offset to imporve the accuracy of the measurements.

function TBrickletAirQuality.GetTemperatureOffset: longint
Returns:
  • offset – Type: longint, Range: [-231 to 231 - 1]

Returns the temperature offset as set by SetTemperatureOffset.

procedure TBrickletAirQuality.GetIAQIndex(out iaqIndex: longint; out iaqIndexAccuracy: byte)
Output Parameters:
  • iaqIndex – Type: longint, Range: [-231 to 231 - 1]
  • iaqIndexAccuracy – Type: byte, Range: See constants

Returns the IAQ index and accuracy. The IAQ index goes from 0 to 500. The higher the IAQ index, the greater the level of air pollution.

IAQ index description

If you want to get the value periodically, it is recommended to use the OnIAQIndex callback. You can set the callback configuration with SetIAQIndexCallbackConfiguration.

The following constants are available for this function:

For iaqIndexAccuracy:

  • BRICKLET_AIR_QUALITY_ACCURACY_UNRELIABLE = 0
  • BRICKLET_AIR_QUALITY_ACCURACY_LOW = 1
  • BRICKLET_AIR_QUALITY_ACCURACY_MEDIUM = 2
  • BRICKLET_AIR_QUALITY_ACCURACY_HIGH = 3
function TBrickletAirQuality.GetTemperature: longint
Returns:
  • temperature – Type: longint, Range: [-231 to 231 - 1]

Returns temperature in steps of 0.01 °C.

If you want to get the value periodically, it is recommended to use the OnTemperature callback. You can set the callback configuration with SetTemperatureCallbackConfiguration.

function TBrickletAirQuality.GetHumidity: longint
Returns:
  • humidity – Type: longint, Range: [-231 to 231 - 1]

Returns relative humidity in steps of 0.01 %RH.

If you want to get the value periodically, it is recommended to use the OnHumidity callback. You can set the callback configuration with SetHumidityCallbackConfiguration.

function TBrickletAirQuality.GetAirPressure: longint
Returns:
  • airPressure – Type: longint, Range: [-231 to 231 - 1]

Returns air pressure in steps of 0.01 mbar.

If you want to get the value periodically, it is recommended to use the OnAirPressure callback. You can set the callback configuration with SetAirPressureCallbackConfiguration.

Advanced Functions

procedure TBrickletAirQuality.RemoveCalibration

Deletes the calibration from flash. After you call this function, you need to power cycle the Air Quality Bricklet.

On the next power up the Bricklet will start a new calibration, as if it was started for the very first time.

The calibration is based on the data of the last four days, so it takes four days until a full calibration is re-established.

New in version 2.0.3 (Plugin).

procedure TBrickletAirQuality.SetBackgroundCalibrationDuration(const duration: byte)
Parameters:
  • duration – Type: byte, Range: See constants

The Air Quality Bricklet uses an automatic background calibration mechanism to calculate the IAQ Index. This calibration mechanism considers a history of measured data. The duration of this history can be configured to either be 4 days or 28 days.

If you keep the Bricklet mostly at one place and it does not get moved around to different environments, we recommend that you use a duration of 28 days.

If you change the duration, the current calibration will be discarded and the calibration will start from beginning again. The configuration of the duration is saved in flash, so you should only have to call this function once in the lifetime of the Bricklet.

The Bricklet has to be power cycled after this function is called for a duration change to take effect.

Before firmware version 2.0.3 this was not configurable and the duration was 4 days.

The default value (since firmware version 2.0.3) is 28 days.

The following constants are available for this function:

For duration:

  • BRICKLET_AIR_QUALITY_DURATION_4_DAYS = 0
  • BRICKLET_AIR_QUALITY_DURATION_28_DAYS = 1

New in version 2.0.3 (Plugin).

function TBrickletAirQuality.GetBackgroundCalibrationDuration: byte
Returns:
  • duration – Type: byte, Range: See constants

Returns the background calibration duration as set by SetBackgroundCalibrationDuration.

The following constants are available for this function:

For duration:

  • BRICKLET_AIR_QUALITY_DURATION_4_DAYS = 0
  • BRICKLET_AIR_QUALITY_DURATION_28_DAYS = 1

New in version 2.0.3 (Plugin).

function TBrickletAirQuality.GetAPIVersion: array [0..2] of byte
Returns:
  • apiVersion – Type: array [0..2] of byte, Range: [0 to 255]

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 TBrickletAirQuality.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_AIR_QUALITY_FUNCTION_SET_TEMPERATURE_OFFSET = 2
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_ALL_VALUES_CALLBACK_CONFIGURATION = 4
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_IAQ_INDEX_CALLBACK_CONFIGURATION = 8
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_TEMPERATURE_CALLBACK_CONFIGURATION = 12
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_HUMIDITY_CALLBACK_CONFIGURATION = 16
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_AIR_PRESSURE_CALLBACK_CONFIGURATION = 20
  • BRICKLET_AIR_QUALITY_FUNCTION_REMOVE_CALIBRATION = 23
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_BACKGROUND_CALIBRATION_DURATION = 24
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_AIR_QUALITY_FUNCTION_RESET = 243
  • BRICKLET_AIR_QUALITY_FUNCTION_WRITE_UID = 248
procedure TBrickletAirQuality.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_AIR_QUALITY_FUNCTION_SET_TEMPERATURE_OFFSET = 2
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_ALL_VALUES_CALLBACK_CONFIGURATION = 4
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_IAQ_INDEX_CALLBACK_CONFIGURATION = 8
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_TEMPERATURE_CALLBACK_CONFIGURATION = 12
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_HUMIDITY_CALLBACK_CONFIGURATION = 16
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_AIR_PRESSURE_CALLBACK_CONFIGURATION = 20
  • BRICKLET_AIR_QUALITY_FUNCTION_REMOVE_CALIBRATION = 23
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_BACKGROUND_CALIBRATION_DURATION = 24
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_AIR_QUALITY_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_AIR_QUALITY_FUNCTION_RESET = 243
  • BRICKLET_AIR_QUALITY_FUNCTION_WRITE_UID = 248
procedure TBrickletAirQuality.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.

procedure TBrickletAirQuality.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 TBrickletAirQuality.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_AIR_QUALITY_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_AIR_QUALITY_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_AIR_QUALITY_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_AIR_QUALITY_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_AIR_QUALITY_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For status:

  • BRICKLET_AIR_QUALITY_BOOTLOADER_STATUS_OK = 0
  • BRICKLET_AIR_QUALITY_BOOTLOADER_STATUS_INVALID_MODE = 1
  • BRICKLET_AIR_QUALITY_BOOTLOADER_STATUS_NO_CHANGE = 2
  • BRICKLET_AIR_QUALITY_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BRICKLET_AIR_QUALITY_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BRICKLET_AIR_QUALITY_BOOTLOADER_STATUS_CRC_MISMATCH = 5
function TBrickletAirQuality.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_AIR_QUALITY_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_AIR_QUALITY_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_AIR_QUALITY_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_AIR_QUALITY_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_AIR_QUALITY_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
procedure TBrickletAirQuality.SetWriteFirmwarePointer(const pointer: longword)
Parameters:
  • pointer – Type: longword, 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 TBrickletAirQuality.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 TBrickletAirQuality.SetStatusLEDConfig(const config: byte)
Parameters:
  • config – Type: byte, Range: See constants

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_AIR_QUALITY_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_AIR_QUALITY_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_AIR_QUALITY_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_AIR_QUALITY_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletAirQuality.GetStatusLEDConfig: byte
Returns:
  • config – Type: byte, Range: See constants

Returns the configuration as set by SetStatusLEDConfig

The following constants are available for this function:

For config:

  • BRICKLET_AIR_QUALITY_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_AIR_QUALITY_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_AIR_QUALITY_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_AIR_QUALITY_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletAirQuality.GetChipTemperature: smallint
Returns:
  • temperature – Type: smallint, Range: [-215 to 215 - 1]

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 TBrickletAirQuality.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 TBrickletAirQuality.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 TBrickletAirQuality.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 TBrickletAirQuality.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
  • hardwareVersion – Type: array [0..2] of byte, Range: [0 to 255]
  • firmwareVersion – Type: array [0..2] of 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' 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 TBrickletAirQuality.SetAllValuesCallbackConfiguration(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 OnAllValues 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 at least one of the values has changed. If the values 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.

procedure TBrickletAirQuality.GetAllValuesCallbackConfiguration(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 SetAllValuesCallbackConfiguration.

procedure TBrickletAirQuality.SetIAQIndexCallbackConfiguration(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 OnIAQIndex 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 at least one of the values has changed. If the values 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.

procedure TBrickletAirQuality.GetIAQIndexCallbackConfiguration(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 SetIAQIndexCallbackConfiguration.

procedure TBrickletAirQuality.SetTemperatureCallbackConfiguration(const period: longword; const valueHasToChange: boolean; const option: char; const min: longint; const max: longint)
Parameters:
  • period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: longint, Range: [-231 to 231 - 1]
  • max – Type: longint, Range: [-231 to 231 - 1]

The period is the period with which the OnTemperature 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the OnTemperature callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

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

The following constants are available for this function:

For option:

  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletAirQuality.GetTemperatureCallbackConfiguration(out period: longword; out valueHasToChange: boolean; out option: char; out min: longint; out max: longint)
Output Parameters:
  • period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: longint, Range: [-231 to 231 - 1]
  • max – Type: longint, Range: [-231 to 231 - 1]

Returns the callback configuration as set by SetTemperatureCallbackConfiguration.

The following constants are available for this function:

For option:

  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletAirQuality.SetHumidityCallbackConfiguration(const period: longword; const valueHasToChange: boolean; const option: char; const min: longint; const max: longint)
Parameters:
  • period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: longint, Range: [-231 to 231 - 1]
  • max – Type: longint, Range: [-231 to 231 - 1]

The period is the period with which the OnHumidity 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the OnHumidity callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

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

The following constants are available for this function:

For option:

  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletAirQuality.GetHumidityCallbackConfiguration(out period: longword; out valueHasToChange: boolean; out option: char; out min: longint; out max: longint)
Output Parameters:
  • period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: longint, Range: [-231 to 231 - 1]
  • max – Type: longint, Range: [-231 to 231 - 1]

Returns the callback configuration as set by SetHumidityCallbackConfiguration.

The following constants are available for this function:

For option:

  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletAirQuality.SetAirPressureCallbackConfiguration(const period: longword; const valueHasToChange: boolean; const option: char; const min: longint; const max: longint)
Parameters:
  • period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: longint, Range: [-231 to 231 - 1]
  • max – Type: longint, Range: [-231 to 231 - 1]

The period is the period with which the OnAirPressure 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the OnAirPressure callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

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

The following constants are available for this function:

For option:

  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletAirQuality.GetAirPressureCallbackConfiguration(out period: longword; out valueHasToChange: boolean; out option: char; out min: longint; out max: longint)
Output Parameters:
  • period – Type: longword, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: longint, Range: [-231 to 231 - 1]
  • max – Type: longint, Range: [-231 to 231 - 1]

Returns the callback configuration as set by SetAirPressureCallbackConfiguration.

The following constants are available for this function:

For option:

  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_AIR_QUALITY_THRESHOLD_OPTION_GREATER = '>'

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

airQuality.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 TBrickletAirQuality.OnAllValues
procedure(sender: TBrickletAirQuality; const iaqIndex: longint; const iaqIndexAccuracy: byte; const temperature: longint; const humidity: longint; const airPressure: longint) of object;
Callback Parameters:
  • sender – Type: TBrickletAirQuality
  • iaqIndex – Type: longint, Range: [-231 to 231 - 1]
  • iaqIndexAccuracy – Type: byte, Range: See constants
  • temperature – Type: longint, Range: [-231 to 231 - 1]
  • humidity – Type: longint, Range: [-231 to 231 - 1]
  • airPressure – Type: longint, Range: [-231 to 231 - 1]

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

The parameters are the same as GetAllValues.

The following constants are available for this function:

For iaqIndexAccuracy:

  • BRICKLET_AIR_QUALITY_ACCURACY_UNRELIABLE = 0
  • BRICKLET_AIR_QUALITY_ACCURACY_LOW = 1
  • BRICKLET_AIR_QUALITY_ACCURACY_MEDIUM = 2
  • BRICKLET_AIR_QUALITY_ACCURACY_HIGH = 3
property TBrickletAirQuality.OnIAQIndex
procedure(sender: TBrickletAirQuality; const iaqIndex: longint; const iaqIndexAccuracy: byte) of object;
Callback Parameters:
  • sender – Type: TBrickletAirQuality
  • iaqIndex – Type: longint, Range: [-231 to 231 - 1]
  • iaqIndexAccuracy – Type: byte, Range: See constants

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

The parameters are the same as GetIAQIndex.

The following constants are available for this function:

For iaqIndexAccuracy:

  • BRICKLET_AIR_QUALITY_ACCURACY_UNRELIABLE = 0
  • BRICKLET_AIR_QUALITY_ACCURACY_LOW = 1
  • BRICKLET_AIR_QUALITY_ACCURACY_MEDIUM = 2
  • BRICKLET_AIR_QUALITY_ACCURACY_HIGH = 3
property TBrickletAirQuality.OnTemperature
procedure(sender: TBrickletAirQuality; const temperature: longint) of object;
Callback Parameters:
  • sender – Type: TBrickletAirQuality
  • temperature – Type: longint, Range: [-231 to 231 - 1]

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

The parameter is the same as GetTemperature.

property TBrickletAirQuality.OnHumidity
procedure(sender: TBrickletAirQuality; const humidity: longint) of object;
Callback Parameters:
  • sender – Type: TBrickletAirQuality
  • humidity – Type: longint, Range: [-231 to 231 - 1]

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

The parameter is the same as GetHumidity.

property TBrickletAirQuality.OnAirPressure
procedure(sender: TBrickletAirQuality; const airPressure: longint) of object;
Callback Parameters:
  • sender – Type: TBrickletAirQuality
  • airPressure – Type: longint, Range: [-231 to 231 - 1]

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

The parameter is the same as GetAirPressure.

Constants

const BRICKLET_AIR_QUALITY_DEVICE_IDENTIFIER

This constant is used to identify a Air Quality 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_AIR_QUALITY_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Air Quality Bricklet.