MATLAB/Octave - Temperature IR Bricklet

This is the description of the MATLAB/Octave API bindings for the Temperature IR Bricklet. General information and technical specifications for the Temperature IR Bricklet are summarized in its hardware description.

An installation guide for the MATLAB/Octave API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple (MATLAB)

Download (matlab_example_simple.m)

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function matlab_example_simple()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletTemperatureIR;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'kqw'; % Change to your UID
    
    ipcon = IPConnection(); % Create IP connection
    tir = BrickletTemperatureIR(UID, ipcon); % Create device object

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

    % Get current object and ambient temperatures (unit is °C/10)
    obj = tir.getObjectTemperature();
    amb = tir.getAmbientTemperature();
    print('Object Temperature: %g°C\n', obj/10.0);
    print('Ambient Temperature: %g°C\n', amb/10.0);

    input('Press any key to exit...\n', 's');
    ipcon.disconnect();
end

Water Boiling (MATLAB)

Download (matlab_example_water_boiling.m)

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function matlab_example_water_boiling()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletTemperatureIR;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'kqw'; % Change to your UID
    
    ipcon = IPConnection(); % Create IP connection
    tir = BrickletTemperatureIR(UID, ipcon); % Create device object

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

    % Set emissivity to 0.98 (emissivity of water)
    tir.setEmissivity(hex2num('FFFF')*0.98);

    % Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    tir.setDebouncePeriod(10000)

    % Register threshold reached callback to function cb_reached
    set(tir, 'ObjectTemperatureReachedCallback', @(h, e) cb_reached(e));

    % Configure threshold for "greater than 100 °C" (unit is °C/10)
    tir.setObjectTemperatureCallbackThreshold('>', 100*10, 0);
    
    input('Press any key to exit...\n', 's');
    ipcon.disconnect();
end

% Callback for object temperature greater than 100 °C
% (parameter has unit °C/10)
function cb_reached(e)
    fprintf('The surface has a temperature of %g°C.\n', e.temperature/10.0);
    fprintf('The water is boiling!\n');
end

Callback (MATLAB)

Download (matlab_example_callback.m)

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function matlab_example_callback()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletTemperatureIR;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'kqw'; % Change to your UID
    
    ipcon = IPConnection(); % Create IP connection
    tir = BrickletTemperatureIR(UID, ipcon); % Create device object

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

    % Set Period for temperature callbacks to 1s (1000ms)
    % Note: The callbacks are only called every second if the 
    %       value has changed since the last call!
    tir.setObjectTemperatureCallbackPeriod(1000);
    tir.setAmbientTemperatureCallbackPeriod(1000);

    % Register object temperature callback to function cb_object
    set(tir, 'ObjectTemperatureCallback', @(h, e) cb_object(e));
    % Register ambient temperature callback to function cb_ambient
    set(tir, 'AmbientTemperatureCallback', @(h, e) cb_ambient(e));

    input('Press any key to exit...\n', 's');
    ipcon.disconnect();
end

% Callback functions for object/ambient temperature callbacks 
% (parameters have unit °C/10)
function cb_object(e)
    fprintf('Object Temperature: %g°C\n', e.temperature/10.0);
end

function cb_ambient(e)
    fprintf('Ambient Temperature: %g°C\n', e.temperature/10.0);
end

Simple (Octave)

Download (octave_example_simple.m)

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function octave_example_simple()
    more off;
    
    HOST = "localhost";
    PORT = 4223;
    UID = "kqw"; % Change to your UID

    ipcon = java_new("com.tinkerforge.IPConnection"); % Create IP connection
    tir = java_new("com.tinkerforge.BrickletTemperatureIR", UID, ipcon); % Create device object

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

    % Get current object and ambient temperatures (unit is °C/10)
    obj = str2num(tir.getObjectTemperature().toString());
    amb = str2num(tir.getAmbientTemperature().toString());
    fprintf("Object Temperature: %g°C\n", obj/10.0);
    fprintf("Ambient Temperature: %g°C\n", amb/10.0);

    input("Press any key to exit...\n", "s");
    ipcon.disconnect();
end

Water Boiling (Octave)

Download (octave_example_water_boiling.m)

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function octave_example_water_boiling()
    more off;
    
    HOST = "localhost";
    PORT = 4223;
    UID = "kqw"; % Change to your UID

    ipcon = java_new("com.tinkerforge.IPConnection"); % Create IP connection
    tir = java_new("com.tinkerforge.BrickletTemperatureIR", UID, ipcon); % Create device object

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

    % Set emissivity to 0.98 (emissivity of water)
    tir.setEmissivity(hex2num("FFFF")*0.98);

    % Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    tir.setDebouncePeriod(10000)

    % Register threshold reached callback to function cb_reached
    tir.addObjectTemperatureReachedCallback(@cb_reached);

    % Configure threshold for "greater than 100 °C" (unit is °C/10)
    tir.setObjectTemperatureCallbackThreshold(">", 100*10, 0);
    
    input("Press any key to exit...\n", "s");
    ipcon.disconnect();
end

% Callback for object temperature greater than 100 °C
% (parameter has unit °C/10)
function cb_reached(e)
    fprintf("The surface has a temperature of %g°C.\n", str2num(e.temperature.toString())/10.0);
    fprintf("The water is boiling!\n");
end

Callback (Octave)

Download (octave_example_callback.m)

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function octave_example_callback()
    more off;
    
    HOST = "localhost";
    PORT = 4223;
    UID = "kqw"; % Change to your UID

    ipcon = java_new("com.tinkerforge.IPConnection"); % Create IP connection
    tir = java_new("com.tinkerforge.BrickletTemperatureIR", UID, ipcon); % Create device object

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

    % Set Period for temperature callbacks to 1s (1000ms)
    % Note: The callbacks are only called every second if the 
    %       value has changed since the last call!
    tir.setObjectTemperatureCallbackPeriod(1000);
    tir.setAmbientTemperatureCallbackPeriod(1000);

    % Register object temperature callback to function cb_object
    tir.addObjectTemperatureCallback(@cb_object);

    % Register ambient temperature callback to function cb_ambient
    tir.addAmbientTemperatureCallback(@cb_ambient);

    input("Press any key to exit...\n", "s");
    ipcon.disconnect();
end

% Callback functions for object/ambient temperature callbacks 
% (parameters have unit °C/10)
function cb_object(e)
    fprintf("Object Temperature: %g°C\n", str2num(e.temperature.toString())/10.0);
end

function cb_ambient(e)
    fprintf("Ambient Temperature: %g°C\n", str2num(e.temperature.toString())/10.0);
end

API

Generally, every method of the MATLAB bindings that returns a value can throw a TimeoutException. This exception gets thrown if the device did not respond. If a cable based connection is used, it is unlikely that this exception gets thrown (assuming nobody unplugs the device). However, if a wireless connection is used, timeouts will occur if the distance to the device gets too big.

Beside the TimeoutException there is also a NotConnectedException that is thrown if a method needs to communicate with the device while the IP Connection is not connected.

Since the MATLAB bindings are based on Java and Java does not support multiple return values and return by reference is not possible for primitive types, we use small classes that only consist of member variables. The member variables of the returned objects are described in the corresponding method descriptions.

The package for all Brick/Bricklet bindings and the IP Connection is com.tinkerforge.*

All methods listed below are thread-safe.

Basic Functions

public class BrickletTemperatureIR(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletTemperatureIR;

temperatureIR = BrickletTemperatureIR('YOUR_DEVICE_UID', ipcon);

In Octave:

temperatureIR = java_new("com.tinkerforge.BrickletTemperatureIR", "YOUR_DEVICE_UID", ipcon);

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

public short getAmbientTemperature()

Returns the ambient temperature of the sensor. The value has a range of -400 to 1250 and is given in °C/10, e.g. a value of 423 means that an ambient temperature of 42.3 °C is measured.

If you want to get the ambient temperature periodically, it is recommended to use the callback AmbientTemperatureCallback and set the period with setAmbientTemperatureCallbackPeriod().

public short getObjectTemperature()

Returns the object temperature of the sensor, i.e. the temperature of the surface of the object the sensor is aimed at. The value has a range of -700 to 3800 and is given in °C/10, e.g. a value of 3001 means that a temperature of 300.1 °C is measured on the surface of the object.

The temperature of different materials is dependent on their emissivity. The emissivity of the material can be set with setEmissivity().

If you want to get the object temperature periodically, it is recommended to use the callback ObjectTemperatureCallback and set the period with setObjectTemperatureCallbackPeriod().

Advanced Functions

public void setEmissivity(int emissivity)

Sets the emissivity that is used to calculate the surface temperature as returned by getObjectTemperature().

The emissivity is usually given as a value between 0.0 and 1.0. A list of emissivities of different materials can be found here.

The parameter of setEmissivity() has to be given with a factor of 65535 (16-bit). For example: An emissivity of 0.1 can be set with the value 6553, an emissivity of 0.5 with the value 32767 and so on.

Note

If you need a precise measurement for the object temperature, it is absolutely crucial that you also provide a precise emissivity.

The default emissivity is 1.0 (value of 65535) and the minimum emissivity the sensor can handle is 0.1 (value of 6553).

public int getEmissivity()

Returns the emissivity as set by setEmissivity().

public short[] getAPIVersion()

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.

public boolean getResponseExpected(short functionId)

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.

public void setResponseExpected(short functionId, boolean responseExpected)

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 and callbacks it is always disabled.

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:

  • BrickletTemperatureIR.FUNCTION_SET_EMISSIVITY = 3
  • BrickletTemperatureIR.FUNCTION_SET_AMBIENT_TEMPERATURE_CALLBACK_PERIOD = 5
  • BrickletTemperatureIR.FUNCTION_SET_OBJECT_TEMPERATURE_CALLBACK_PERIOD = 7
  • BrickletTemperatureIR.FUNCTION_SET_AMBIENT_TEMPERATURE_CALLBACK_THRESHOLD = 9
  • BrickletTemperatureIR.FUNCTION_SET_OBJECT_TEMPERATURE_CALLBACK_THRESHOLD = 11
  • BrickletTemperatureIR.FUNCTION_SET_DEBOUNCE_PERIOD = 13
public void setResponseExpectedAll(boolean responseExpected)

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

public BrickletTemperatureIR.Identity getIdentity()

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.

The returned object has the public member variables String uid, String connectedUid, char position, short[] hardwareVersion, short[] firmwareVersion and int deviceIdentifier.

Callback Configuration Functions

public void setAmbientTemperatureCallbackPeriod(long period)

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

AmbientTemperatureCallback is only triggered if the temperature has changed since the last triggering.

The default value is 0.

public long getAmbientTemperatureCallbackPeriod()

Returns the period as set by setAmbientTemperatureCallbackPeriod().

public void setObjectTemperatureCallbackPeriod(long period)

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

ObjectTemperatureCallback is only triggered if the temperature has changed since the last triggering.

The default value is 0.

public long getObjectTemperatureCallbackPeriod()

Returns the period as set by setObjectTemperatureCallbackPeriod().

public void setAmbientTemperatureCallbackThreshold(char option, short min, short max)

Sets the thresholds for the AmbientTemperatureReachedCallback callback.

The following options are possible:

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

  • BrickletTemperatureIR.THRESHOLD_OPTION_OFF = 'x'
  • BrickletTemperatureIR.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletTemperatureIR.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletTemperatureIR.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletTemperatureIR.THRESHOLD_OPTION_GREATER = '>'
public BrickletTemperatureIR.AmbientTemperatureCallbackThreshold getAmbientTemperatureCallbackThreshold()

Returns the threshold as set by setAmbientTemperatureCallbackThreshold().

The following constants are available for this function:

  • BrickletTemperatureIR.THRESHOLD_OPTION_OFF = 'x'
  • BrickletTemperatureIR.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletTemperatureIR.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletTemperatureIR.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletTemperatureIR.THRESHOLD_OPTION_GREATER = '>'

The returned object has the public member variables char option, short min and short max.

public void setObjectTemperatureCallbackThreshold(char option, short min, short max)

Sets the thresholds for the ObjectTemperatureReachedCallback callback.

The following options are possible:

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

  • BrickletTemperatureIR.THRESHOLD_OPTION_OFF = 'x'
  • BrickletTemperatureIR.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletTemperatureIR.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletTemperatureIR.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletTemperatureIR.THRESHOLD_OPTION_GREATER = '>'
public BrickletTemperatureIR.ObjectTemperatureCallbackThreshold getObjectTemperatureCallbackThreshold()

Returns the threshold as set by setObjectTemperatureCallbackThreshold().

The following constants are available for this function:

  • BrickletTemperatureIR.THRESHOLD_OPTION_OFF = 'x'
  • BrickletTemperatureIR.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletTemperatureIR.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletTemperatureIR.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletTemperatureIR.THRESHOLD_OPTION_GREATER = '>'

The returned object has the public member variables char option, short min and short max.

public void setDebouncePeriod(long debounce)

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

public long getDebouncePeriod()

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 with "set" function of MATLAB. The parameters consist of the IP Connection object, the callback name and the callback function. For example, it looks like this in MATLAB:

function cb_example(e)
    fprintf('Parameter: %s\n', e.param);
end

set(device, 'ExampleCallback', @(h, e) cb_example(e));

Due to a difference in the Octave Java support the "set" function cannot be used in Octave. The registration is done with "add*Callback" functions of the device object. It looks like this in Octave:

function cb_example(e)
    fprintf("Parameter: %s\n", e.param);
end

device.addExampleCallback(@cb_example);

It is possible to add several callbacks and to remove them with the corresponding "remove*Callback" function.

The parameters of the callback are passed to the callback function as fields of the structure e, which is derived from the java.util.EventObject class. The available callback names with corresponding structure fields 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.

public callback BrickletTemperatureIR.AmbientTemperatureCallback
Parameters:temperature -- short

This callback is triggered periodically with the period that is set by setAmbientTemperatureCallbackPeriod(). The parameter is the ambient temperature of the sensor.

AmbientTemperatureCallback is only triggered if the ambient temperature has changed since the last triggering.

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addAmbientTemperatureCallback() function. An added callback function can be removed with the removeAmbientTemperatureCallback() function.

public callback BrickletTemperatureIR.ObjectTemperatureCallback
Parameters:temperature -- short

This callback is triggered periodically with the period that is set by setObjectTemperatureCallbackPeriod(). The parameter is the object temperature of the sensor.

ObjectTemperatureCallback is only triggered if the object temperature has changed since the last triggering.

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addObjectTemperatureCallback() function. An added callback function can be removed with the removeObjectTemperatureCallback() function.

public callback BrickletTemperatureIR.AmbientTemperatureReachedCallback
Parameters:temperature -- short

This callback is triggered when the threshold as set by setAmbientTemperatureCallbackThreshold() is reached. The parameter is the ambient temperature of the sensor.

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

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addAmbientTemperatureReachedCallback() function. An added callback function can be removed with the removeAmbientTemperatureReachedCallback() function.

public callback BrickletTemperatureIR.ObjectTemperatureReachedCallback
Parameters:temperature -- short

This callback is triggered when the threshold as set by setObjectTemperatureCallbackThreshold() is reached. The parameter is the object temperature of the sensor.

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

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addObjectTemperatureReachedCallback() function. An added callback function can be removed with the removeObjectTemperatureReachedCallback() function.

Constants

public static final int BrickletTemperatureIR.DEVICE_IDENTIFIER

This constant is used to identify a Temperature IR Bricklet.

The getIdentity() function and the EnumerateCallback callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

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