Delphi/Lazarus - PTC Bricklet

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

type
  TExample = class
  private
    ipcon: TIPConnection;
    ptc: TBrickletPTC;
  public
    procedure Execute;
  end;

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

var
  e: TExample;

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

  { Create device object }
  ptc := TBrickletPTC.Create(UID, ipcon);

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

  { Get current temperature }
  temperature := ptc.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)

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program ExampleCallback;

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

uses
  SysUtils, IPConnection, BrickletPTC;

type
  TExample = class
  private
    ipcon: TIPConnection;
    ptc: TBrickletPTC;
  public
    procedure TemperatureCB(sender: TBrickletPTC; const temperature: longint);
    procedure Execute;
  end;

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

var
  e: TExample;

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

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

  { Create device object }
  ptc := TBrickletPTC.Create(UID, ipcon);

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

  { Register temperature callback to procedure TemperatureCB }
  ptc.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! }
  ptc.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)

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program ExampleThreshold;

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

uses
  SysUtils, IPConnection, BrickletPTC;

type
  TExample = class
  private
    ipcon: TIPConnection;
    ptc: TBrickletPTC;
  public
    procedure TemperatureReachedCB(sender: TBrickletPTC; const temperature: longint);
    procedure Execute;
  end;

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

var
  e: TExample;

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

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

  { Create device object }
  ptc := TBrickletPTC.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) }
  ptc.SetDebouncePeriod(10000);

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

  { Configure threshold for temperature "greater than 30 °C" }
  ptc.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 TBrickletPTC.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

ptc := TBrickletPTC.Create('YOUR_DEVICE_UID', ipcon);

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

function TBrickletPTC.GetTemperature: longint

Returns the temperature of connected sensor. The value has a range of -246 to 849 °C and is given in °C/100, e.g. a value of 4223 means that a temperature of 42.23 °C is measured.

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

function TBrickletPTC.IsSensorConnected: boolean

Returns true if the sensor is connected correctly.

If this function returns false, there is either no Pt100 or Pt1000 sensor connected, the sensor is connected incorrectly or the sensor itself is faulty.

procedure TBrickletPTC.SetWireMode(const mode: byte)

Sets the wire mode of the sensor. Possible values are 2, 3 and 4 which correspond to 2-, 3- and 4-wire sensors. The value has to match the jumper configuration on the Bricklet.

The default value is 2 = 2-wire.

The following constants are available for this function:

  • BRICKLET_PTC_WIRE_MODE_2 = 2
  • BRICKLET_PTC_WIRE_MODE_3 = 3
  • BRICKLET_PTC_WIRE_MODE_4 = 4
function TBrickletPTC.GetWireMode: byte

Returns the wire mode as set by SetWireMode

The following constants are available for this function:

  • BRICKLET_PTC_WIRE_MODE_2 = 2
  • BRICKLET_PTC_WIRE_MODE_3 = 3
  • BRICKLET_PTC_WIRE_MODE_4 = 4

Advanced Functions

function TBrickletPTC.GetResistance: longint

Returns the value as measured by the MAX31865 precision delta-sigma ADC.

The value can be converted with the following formulas:

  • Pt100: resistance = (value * 390) / 32768
  • Pt1000: resistance = (value * 3900) / 32768

If you want to get the resistance periodically, it is recommended to use the OnResistance callback and set the period with SetResistanceCallbackPeriod.

procedure TBrickletPTC.SetNoiseRejectionFilter(const filter: byte)

Sets the noise rejection filter to either 50Hz (0) or 60Hz (1). Noise from 50Hz or 60Hz power sources (including harmonics of the AC power's fundamental frequency) is attenuated by 82dB.

Default value is 0 = 50Hz.

The following constants are available for this function:

  • BRICKLET_PTC_FILTER_OPTION_50HZ = 0
  • BRICKLET_PTC_FILTER_OPTION_60HZ = 1
function TBrickletPTC.GetNoiseRejectionFilter: byte

Returns the noise rejection filter option as set by SetNoiseRejectionFilter

The following constants are available for this function:

  • BRICKLET_PTC_FILTER_OPTION_50HZ = 0
  • BRICKLET_PTC_FILTER_OPTION_60HZ = 1
function TBrickletPTC.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 TBrickletPTC.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 TBrickletPTC.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_PTC_FUNCTION_SET_TEMPERATURE_CALLBACK_PERIOD = 3
  • BRICKLET_PTC_FUNCTION_SET_RESISTANCE_CALLBACK_PERIOD = 5
  • BRICKLET_PTC_FUNCTION_SET_TEMPERATURE_CALLBACK_THRESHOLD = 7
  • BRICKLET_PTC_FUNCTION_SET_RESISTANCE_CALLBACK_THRESHOLD = 9
  • BRICKLET_PTC_FUNCTION_SET_DEBOUNCE_PERIOD = 11
  • BRICKLET_PTC_FUNCTION_SET_NOISE_REJECTION_FILTER = 17
  • BRICKLET_PTC_FUNCTION_SET_WIRE_MODE = 20
  • BRICKLET_PTC_FUNCTION_SET_SENSOR_CONNECTED_CALLBACK_CONFIGURATION = 22
procedure TBrickletPTC.SetResponseExpectedAll(const responseExpected: boolean)

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

procedure TBrickletPTC.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 TBrickletPTC.SetTemperatureCallbackPeriod(const period: longword)

Sets the period in ms 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.

The default value is 0.

function TBrickletPTC.GetTemperatureCallbackPeriod: longword

Returns the period as set by SetTemperatureCallbackPeriod.

procedure TBrickletPTC.SetResistanceCallbackPeriod(const period: longword)

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

The OnResistance callback is only triggered if the resistance has changed since the last triggering.

The default value is 0.

function TBrickletPTC.GetResistanceCallbackPeriod: longword

Returns the period as set by SetResistanceCallbackPeriod.

procedure TBrickletPTC.SetTemperatureCallbackThreshold(const option: char; const min: longint; const max: longint)

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

The following constants are available for this function:

  • BRICKLET_PTC_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_PTC_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_PTC_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_PTC_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_PTC_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletPTC.GetTemperatureCallbackThreshold(out option: char; out min: longint; out max: longint)

Returns the threshold as set by SetTemperatureCallbackThreshold.

The following constants are available for this function:

  • BRICKLET_PTC_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_PTC_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_PTC_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_PTC_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_PTC_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletPTC.SetResistanceCallbackThreshold(const option: char; const min: longint; const max: longint)

Sets the thresholds for the OnResistanceReached 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 default value is ('x', 0, 0).

The following constants are available for this function:

  • BRICKLET_PTC_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_PTC_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_PTC_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_PTC_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_PTC_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletPTC.GetResistanceCallbackThreshold(out option: char; out min: longint; out max: longint)

Returns the threshold as set by SetResistanceCallbackThreshold.

The following constants are available for this function:

  • BRICKLET_PTC_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_PTC_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_PTC_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_PTC_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_PTC_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletPTC.SetDebouncePeriod(const debounce: longword)

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

function TBrickletPTC.GetDebouncePeriod: longword

Returns the debounce period as set by SetDebouncePeriod.

procedure TBrickletPTC.SetSensorConnectedCallbackConfiguration(const enabled: boolean)

If you enable this callback, the OnSensorConnected callback is triggered every time a Pt sensor is connected/disconnected.

By default this callback is disabled.

New in version 2.0.2 (Plugin).

function TBrickletPTC.GetSensorConnectedCallbackConfiguration: boolean

Returns the configuration as set by SetSensorConnectedCallbackConfiguration.

New in version 2.0.2 (Plugin).

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

ptc.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 TBrickletPTC.OnTemperature
procedure(sender: TBrickletPTC; const temperature: longint) of object;

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

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

property TBrickletPTC.OnTemperatureReached
procedure(sender: TBrickletPTC; const temperature: longint) of object;

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

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

property TBrickletPTC.OnResistance
procedure(sender: TBrickletPTC; const resistance: longint) of object;

This callback is triggered periodically with the period that is set by SetResistanceCallbackPeriod. The parameter is the resistance of the connected sensor.

The OnResistance callback is only triggered if the resistance has changed since the last triggering.

property TBrickletPTC.OnResistanceReached
procedure(sender: TBrickletPTC; const resistance: longint) of object;

This callback is triggered when the threshold as set by SetResistanceCallbackThreshold is reached. The parameter is the resistance of the connected sensor.

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

property TBrickletPTC.OnSensorConnected
procedure(sender: TBrickletPTC; const connected: boolean) of object;

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

The parameter is the same as IsSensorConnected.

New in version 2.0.2 (Plugin).

Constants

const BRICKLET_PTC_DEVICE_IDENTIFIER

This constant is used to identify a PTC 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_PTC_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a PTC Bricklet.