Software / API Bindings / Delphi/Lazarus / API Reference and Examples / Bricklets / Temperature Bricklet

Delphi/Lazarus - Temperature Bricklet¶

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

program ExampleSimple;

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

uses
  SysUtils, IPConnection, BrickletTemperature;

type
  TExample = class
  private
    ipcon: TIPConnection;
    t: TBrickletTemperature;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

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

  { Create device object }
  t := TBrickletTemperature.Create(UID, ipcon);

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

  { Get current temperature }
  temperature := t.GetTemperature;
  WriteLn(Format('Temperature: %f °C', [temperature/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)

program ExampleCallback;

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

uses
  SysUtils, IPConnection, BrickletTemperature;

type
  TExample = class
  private
    ipcon: TIPConnection;
    t: TBrickletTemperature;
  public
    procedure TemperatureCB(sender: TBrickletTemperature; const temperature: smallint);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for temperature callback }
procedure TExample.TemperatureCB(sender: TBrickletTemperature;
                                 const temperature: smallint);
begin
  WriteLn(Format('Temperature: %f °C', [temperature/100.0]));
end;

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

  { Create device object }
  t := TBrickletTemperature.Create(UID, ipcon);

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

  { Register temperature callback to procedure TemperatureCB }
  t.OnTemperature := {$ifdef FPC}@{$endif}TemperatureCB;

  { Set period for temperature callback to 1s (1000ms)
    Note: The temperature callback is only called every second
          if the temperature has changed since the last call! }
  t.SetTemperatureCallbackPeriod(1000);

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

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

Threshold¶

Download (ExampleThreshold.pas)

program ExampleThreshold;

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

uses
  SysUtils, IPConnection, BrickletTemperature;

type
  TExample = class
  private
    ipcon: TIPConnection;
    t: TBrickletTemperature;
  public
    procedure TemperatureReachedCB(sender: TBrickletTemperature;
                                   const temperature: smallint);
    procedure Execute;
  end;

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

var
  e: TExample;

{ Callback procedure for temperature reached callback }
procedure TExample.TemperatureReachedCB(sender: TBrickletTemperature;
                                        const temperature: smallint);
begin
  WriteLn(Format('Temperature: %f °C', [temperature/100.0]));
  WriteLn('It is too hot, we need air conditioning!');
end;

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

  { Create device object }
  t := TBrickletTemperature.Create(UID, ipcon);

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

  { Get threshold callbacks with a debounce time of 10 seconds (10000ms) }
  t.SetDebouncePeriod(10000);

  { Register temperature reached callback to procedure TemperatureReachedCB }
  t.OnTemperatureReached := {$ifdef FPC}@{$endif}TemperatureReachedCB;

  { Configure threshold for temperature "greater than 30 °C" }
  t.SetTemperatureCallbackThreshold('>', 30*100, 0);

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

Parameters:	uid – Type: string ipcon – Type: TIPConnection
Returns:	temperature – Type: TBrickletTemperature

Creates an object with the unique device ID uid:

temperature := TBrickletTemperature.Create('YOUR_DEVICE_UID', ipcon);

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

function TBrickletTemperature.GetTemperature: smallint¶

Returns:	temperature – Type: smallint, Unit: 1/100 °C, Range: [-2500 to 8500]

Returns the temperature of the sensor.

If you want to get the temperature periodically, it is recommended to use the OnTemperature callback and set the period with SetTemperatureCallbackPeriod.

Advanced Functions¶

procedure TBrickletTemperature.SetI2CMode(const mode: byte)¶

Parameters:	mode – Type: byte, Range: See constants, Default: 0

Sets the I2C mode. Possible modes are:

0: Fast (400kHz)
1: Slow (100kHz)

If you have problems with obvious outliers in the Temperature Bricklet measurements, they may be caused by EMI issues. In this case it may be helpful to lower the I2C speed.

It is however not recommended to lower the I2C speed in applications where a high throughput needs to be achieved.

The following constants are available for this function:

For mode:

BRICKLET_TEMPERATURE_I2C_MODE_FAST = 0
BRICKLET_TEMPERATURE_I2C_MODE_SLOW = 1

New in version 2.0.1 (Plugin).

function TBrickletTemperature.GetI2CMode: byte¶

Returns:	mode – Type: byte, Range: See constants, Default: 0

Returns the I2C mode as set by SetI2CMode.

The following constants are available for this function:

For mode:

BRICKLET_TEMPERATURE_I2C_MODE_FAST = 0
BRICKLET_TEMPERATURE_I2C_MODE_SLOW = 1

New in version 2.0.1 (Plugin).

procedure TBrickletTemperature.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:

Output Parameters:	uid – Type: string, Length: up to 8 connectedUid – Type: string, Length: up to 8 position – Type: char, Range: ['a' to 'h', 'z'] hardwareVersion – Type: array [0..2] of byte 0: major – Type: byte, Range: [0 to 255] 1: minor – Type: byte, Range: [0 to 255] 2: revision – Type: byte, Range: [0 to 255] firmwareVersion – Type: array [0..2] of byte 0: major – Type: byte, Range: [0 to 255] 1: minor – Type: byte, Range: [0 to 255] 2: revision – Type: byte, Range: [0 to 255] deviceIdentifier – Type: word, Range: [0 to 2¹⁶ - 1]

uid – Type: string, Length: up to 8
connectedUid – Type: string, Length: up to 8
position – Type: char, Range: ['a' to 'h', 'z']
hardwareVersion – Type: array [0..2] of byte

0: major – Type: byte, Range: [0 to 255]
1: minor – Type: byte, Range: [0 to 255]
2: revision – Type: byte, Range: [0 to 255]

firmwareVersion – Type: array [0..2] of byte

0: major – Type: byte, Range: [0 to 255]
1: minor – Type: byte, Range: [0 to 255]
2: revision – Type: byte, Range: [0 to 255]

deviceIdentifier – Type: word, Range: [0 to 2¹⁶ - 1]

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

The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

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

Callback Configuration Functions¶

procedure TBrickletTemperature.SetTemperatureCallbackPeriod(const period: longword)¶

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

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

The OnTemperature callback is only triggered if the temperature has changed since the last triggering.

function TBrickletTemperature.GetTemperatureCallbackPeriod: longword¶

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

Returns the period as set by SetTemperatureCallbackPeriod.

procedure TBrickletTemperature.SetTemperatureCallbackThreshold(const option: char; const min: smallint; const max: smallint)¶

Parameters:	option – Type: char, Range: See constants, Default: 'x' min – Type: smallint, Unit: 1/100 °C, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 max – Type: smallint, Unit: 1/100 °C, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0

Sets the thresholds for the OnTemperatureReached callback.

The following options are possible:

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

The following constants are available for this function:

For option:

BRICKLET_TEMPERATURE_THRESHOLD_OPTION_OFF = 'x'
BRICKLET_TEMPERATURE_THRESHOLD_OPTION_OUTSIDE = 'o'
BRICKLET_TEMPERATURE_THRESHOLD_OPTION_INSIDE = 'i'
BRICKLET_TEMPERATURE_THRESHOLD_OPTION_SMALLER = '<'
BRICKLET_TEMPERATURE_THRESHOLD_OPTION_GREATER = '>'

procedure TBrickletTemperature.GetTemperatureCallbackThreshold(out option: char; out min: smallint; out max: smallint)¶

Output Parameters:	option – Type: char, Range: See constants, Default: 'x' min – Type: smallint, Unit: 1/100 °C, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 max – Type: smallint, Unit: 1/100 °C, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0

Returns the threshold as set by SetTemperatureCallbackThreshold.

The following constants are available for this function:

For option:

BRICKLET_TEMPERATURE_THRESHOLD_OPTION_OFF = 'x'
BRICKLET_TEMPERATURE_THRESHOLD_OPTION_OUTSIDE = 'o'
BRICKLET_TEMPERATURE_THRESHOLD_OPTION_INSIDE = 'i'
BRICKLET_TEMPERATURE_THRESHOLD_OPTION_SMALLER = '<'
BRICKLET_TEMPERATURE_THRESHOLD_OPTION_GREATER = '>'

procedure TBrickletTemperature.SetDebouncePeriod(const debounce: longword)¶

Parameters:	debounce – Type: longword, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100

Sets the period with which the threshold callback

OnTemperatureReached

is triggered, if the threshold

SetTemperatureCallbackThreshold

keeps being reached.

function TBrickletTemperature.GetDebouncePeriod: longword¶

Returns:	debounce – Type: longword, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100

Returns the debounce period as set by SetDebouncePeriod.

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a procedure to an callback property of the device object:

procedure TExample.MyCallback(sender: TBrickletTemperature; const value: longint);
begin
  WriteLn(Format('Value: %d', [value]));
end;

temperature.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 TBrickletTemperature.OnTemperature¶

procedure(sender: TBrickletTemperature; const temperature: smallint) of object;

Callback Parameters:	sender – Type: TBrickletTemperature temperature – Type: smallint, Unit: 1/100 °C, Range: [-2500 to 8500]

This callback is triggered periodically with the period that is set by SetTemperatureCallbackPeriod. The parameter is the temperature of the sensor.

The OnTemperature callback is only triggered if the temperature has changed since the last triggering.

property TBrickletTemperature.OnTemperatureReached¶

procedure(sender: TBrickletTemperature; const temperature: smallint) of object;

Callback Parameters:	sender – Type: TBrickletTemperature temperature – Type: smallint, Unit: 1/100 °C, Range: [-2500 to 8500]

This callback is triggered when the threshold as set by SetTemperatureCallbackThreshold is reached. The parameter is the temperature of the sensor.

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

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

function TBrickletTemperature.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 TBrickletTemperature.GetResponseExpected(const functionId: byte): boolean¶

Parameters:	functionId – Type: byte, Range: See constants
Returns:	responseExpected – Type: boolean

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by SetResponseExpected. For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

BRICKLET_TEMPERATURE_FUNCTION_SET_TEMPERATURE_CALLBACK_PERIOD = 2
BRICKLET_TEMPERATURE_FUNCTION_SET_TEMPERATURE_CALLBACK_THRESHOLD = 4
BRICKLET_TEMPERATURE_FUNCTION_SET_DEBOUNCE_PERIOD = 6
BRICKLET_TEMPERATURE_FUNCTION_SET_I2C_MODE = 10

procedure TBrickletTemperature.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.

The following constants are available for this function:

For functionId:

BRICKLET_TEMPERATURE_FUNCTION_SET_TEMPERATURE_CALLBACK_PERIOD = 2
BRICKLET_TEMPERATURE_FUNCTION_SET_TEMPERATURE_CALLBACK_THRESHOLD = 4
BRICKLET_TEMPERATURE_FUNCTION_SET_DEBOUNCE_PERIOD = 6
BRICKLET_TEMPERATURE_FUNCTION_SET_I2C_MODE = 10

procedure TBrickletTemperature.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_TEMPERATURE_DEVICE_IDENTIFIER¶

This constant is used to identify a Temperature 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_TEMPERATURE_DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a Temperature Bricklet.