Delphi/Lazarus - Humidity Bricklet 2.0

This is the description of the Delphi/Lazarus API bindings for the Humidity Bricklet 2.0. General information and technical specifications for the Humidity 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, BrickletHumidityV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    h: TBrickletHumidityV2;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

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

  { Create device object }
  h := TBrickletHumidityV2.Create(UID, ipcon);

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

  { Get current humidity }
  humidity := h.GetHumidity;
  WriteLn(Format('Humidity: %f %%RH', [humidity/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, BrickletHumidityV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    h: TBrickletHumidityV2;
  public
    procedure HumidityCB(sender: TBrickletHumidityV2; const humidity: word);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for humidity callback }
procedure TExample.HumidityCB(sender: TBrickletHumidityV2; const humidity: word);
begin
  WriteLn(Format('Humidity: %f %%RH', [humidity/100.0]));
end;

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

  { Create device object }
  h := TBrickletHumidityV2.Create(UID, ipcon);

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

  { Register humidity callback to procedure HumidityCB }
  h.OnHumidity := {$ifdef FPC}@{$endif}HumidityCB;

  { Set period for humidity callback to 1s (1000ms) without a threshold }
  h.SetHumidityCallbackConfiguration(1000, false, 'x', 0, 0);

  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, BrickletHumidityV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    h: TBrickletHumidityV2;
  public
    procedure HumidityCB(sender: TBrickletHumidityV2; const humidity: word);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for humidity callback }
procedure TExample.HumidityCB(sender: TBrickletHumidityV2; const humidity: word);
begin
  WriteLn(Format('Humidity: %f %%RH', [humidity/100.0]));
  WriteLn('Recommended humidity for human comfort is 30 to 60 %RH.');
end;

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

  { Create device object }
  h := TBrickletHumidityV2.Create(UID, ipcon);

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

  { Register humidity callback to procedure HumidityCB }
  h.OnHumidity := {$ifdef FPC}@{$endif}HumidityCB;

  { Configure threshold for humidity "outside of 30 to 60 %RH"
    with a debounce period of 10s (10000ms) }
  h.SetHumidityCallbackConfiguration(10000, false, 'o', 30*100, 60*100);

  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 TBrickletHumidityV2.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

humidityV2 := TBrickletHumidityV2.Create('YOUR_DEVICE_UID', ipcon);

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

function TBrickletHumidityV2.GetHumidity: word

Returns the humidity measured by the sensor. The value has a range of 0 to 10000 and is given in %RH/100 (Relative Humidity), i.e. a value of 4223 means that a humidity of 42.23 %RH is measured.

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 TBrickletHumidityV2.GetTemperature: smallint

Returns the temperature measured by the sensor. The value has a range of -4000 to 16500 and is given in °C/100, i.e. a value of 3200 means that a temperature of 32.00 °C is measured.

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

procedure TBrickletHumidityV2.SetHeaterConfiguration(const heaterConfig: byte)

Enables/disables the heater. The heater can be used to dry the sensor in extremely wet conditions.

By default the heater is disabled.

The following constants are available for this function:

  • BRICKLET_HUMIDITY_V2_HEATER_CONFIG_DISABLED = 0
  • BRICKLET_HUMIDITY_V2_HEATER_CONFIG_ENABLED = 1
function TBrickletHumidityV2.GetHeaterConfiguration: byte

Returns the heater configuration as set by SetHeaterConfiguration.

The following constants are available for this function:

  • BRICKLET_HUMIDITY_V2_HEATER_CONFIG_DISABLED = 0
  • BRICKLET_HUMIDITY_V2_HEATER_CONFIG_ENABLED = 1
procedure TBrickletHumidityV2.SetMovingAverageConfiguration(const movingAverageLengthHumidity: word; const movingAverageLengthTemperature: word)

Sets the length of a moving averaging for the humidity and temperature.

Setting the length to 1 will turn the averaging off. With less averaging, there is more noise on the data.

The range for the averaging is 1-1000.

New data is gathered every 50ms*. With a moving average of length 1000 the resulting averaging window has a length of 50s. If you want to do long term measurements the longest moving average will give the cleanest results.

The default value is 5.

* In firmware version 2.0.3 we added the SetSamplesPerSecond function. It configures the measurement frequency. Since high frequencies can result in self-heating of th IC, changed the default value from 20 samples per second to 1. With 1 sample per second a moving average length of 1000 would result in an averaging window of 1000 seconds!

procedure TBrickletHumidityV2.GetMovingAverageConfiguration(out movingAverageLengthHumidity: word; out movingAverageLengthTemperature: word)

Returns the moving average configuration as set by SetMovingAverageConfiguration.

procedure TBrickletHumidityV2.SetSamplesPerSecond(const sps: byte)

Sets the samples per second that are gathered by the humidity/temperature sensor HDC1080.

We added this function since we found out that a high measurement frequency can lead to self-heating of the sensor. Which can distort the temperature measurement.

If you don't need a lot of measurements, you can use the lowest available measurement frequency of 0.1 samples per second for the least amount of self-heating.

Before version 2.0.3 the default was 20 samples per second. The new default is 1 sample per second.

The following constants are available for this function:

  • BRICKLET_HUMIDITY_V2_SPS_20 = 0
  • BRICKLET_HUMIDITY_V2_SPS_10 = 1
  • BRICKLET_HUMIDITY_V2_SPS_5 = 2
  • BRICKLET_HUMIDITY_V2_SPS_1 = 3
  • BRICKLET_HUMIDITY_V2_SPS_02 = 4
  • BRICKLET_HUMIDITY_V2_SPS_01 = 5

New in version 2.0.3 (Plugin).

function TBrickletHumidityV2.GetSamplesPerSecond: byte

Returnes the samples per second, as set by SetSamplesPerSecond.

The following constants are available for this function:

  • BRICKLET_HUMIDITY_V2_SPS_20 = 0
  • BRICKLET_HUMIDITY_V2_SPS_10 = 1
  • BRICKLET_HUMIDITY_V2_SPS_5 = 2
  • BRICKLET_HUMIDITY_V2_SPS_1 = 3
  • BRICKLET_HUMIDITY_V2_SPS_02 = 4
  • BRICKLET_HUMIDITY_V2_SPS_01 = 5

New in version 2.0.3 (Plugin).

Advanced Functions

function TBrickletHumidityV2.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 TBrickletHumidityV2.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 TBrickletHumidityV2.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_HUMIDITY_V2_FUNCTION_SET_HUMIDITY_CALLBACK_CONFIGURATION = 2
  • BRICKLET_HUMIDITY_V2_FUNCTION_SET_TEMPERATURE_CALLBACK_CONFIGURATION = 6
  • BRICKLET_HUMIDITY_V2_FUNCTION_SET_HEATER_CONFIGURATION = 9
  • BRICKLET_HUMIDITY_V2_FUNCTION_SET_MOVING_AVERAGE_CONFIGURATION = 11
  • BRICKLET_HUMIDITY_V2_FUNCTION_SET_SAMPLES_PER_SECOND = 13
  • BRICKLET_HUMIDITY_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_HUMIDITY_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_HUMIDITY_V2_FUNCTION_RESET = 243
  • BRICKLET_HUMIDITY_V2_FUNCTION_WRITE_UID = 248
procedure TBrickletHumidityV2.SetResponseExpectedAll(const responseExpected: boolean)

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

procedure TBrickletHumidityV2.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 TBrickletHumidityV2.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_HUMIDITY_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_STATUS_OK = 0
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
function TBrickletHumidityV2.GetBootloaderMode: byte

Returns the current bootloader mode, see SetBootloaderMode.

The following constants are available for this function:

  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_HUMIDITY_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
procedure TBrickletHumidityV2.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 TBrickletHumidityV2.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 TBrickletHumidityV2.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_HUMIDITY_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_HUMIDITY_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_HUMIDITY_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_HUMIDITY_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletHumidityV2.GetStatusLEDConfig: byte

Returns the configuration as set by SetStatusLEDConfig

The following constants are available for this function:

  • BRICKLET_HUMIDITY_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_HUMIDITY_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_HUMIDITY_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_HUMIDITY_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletHumidityV2.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 TBrickletHumidityV2.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 TBrickletHumidityV2.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 TBrickletHumidityV2.ReadUID: longword

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

procedure TBrickletHumidityV2.GetIdentity(out uid: string; out connectedUid: string; out position: char; out hardwareVersion: array [0..2] of byte; out firmwareVersion: array [0..2] of byte; out deviceIdentifier: word)

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

procedure TBrickletHumidityV2.SetHumidityCallbackConfiguration(const period: longword; const valueHasToChange: boolean; const option: char; const min: word; const max: word)

The period in ms 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:

  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletHumidityV2.GetHumidityCallbackConfiguration(out period: longword; out valueHasToChange: boolean; out option: char; out min: word; out max: word)

Returns the callback configuration as set by SetHumidityCallbackConfiguration.

The following constants are available for this function:

  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletHumidityV2.SetTemperatureCallbackConfiguration(const period: longword; const valueHasToChange: boolean; const option: char; const min: smallint; const max: smallint)

The period in ms 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:

  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletHumidityV2.GetTemperatureCallbackConfiguration(out period: longword; out valueHasToChange: boolean; out option: char; out min: smallint; out max: smallint)

Returns the callback configuration as set by SetTemperatureCallbackConfiguration.

The following constants are available for this function:

  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_HUMIDITY_V2_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_HUMIDITY_V2_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: TBrickletHumidityV2; const param: word);
begin
  WriteLn(param);
end;

humidityV2.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 TBrickletHumidityV2.OnHumidity
procedure(sender: TBrickletHumidityV2; const humidity: word) of object;

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

The parameter is the same as GetHumidity.

property TBrickletHumidityV2.OnTemperature
procedure(sender: TBrickletHumidityV2; const temperature: smallint) of object;

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

The parameter is the same as GetTemperature.

Constants

const BRICKLET_HUMIDITY_V2_DEVICE_IDENTIFIER

This constant is used to identify a Humidity Bricklet 2.0.

The GetIdentity function and the OnEnumerate callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

const BRICKLET_HUMIDITY_V2_DEVICE_DISPLAY_NAME

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