This is the description of the MATLAB/Octave API bindings for the Piezo Buzzer Bricklet. General information and technical specifications for the Piezo Buzzer Bricklet are summarized in its hardware description.
An installation guide for the MATLAB/Octave API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
Download (matlab_example_beep.m)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | function matlab_example_beep()
import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletPiezoBuzzer;
HOST = 'localhost';
PORT = 4223;
UID = 'XYZ'; % Change XYZ to the UID of your Piezo Buzzer Bricklet
ipcon = IPConnection(); % Create IP connection
pb = handle(BrickletPiezoBuzzer(UID, ipcon), 'CallbackProperties'); % Create device object
ipcon.connect(HOST, PORT); % Connect to brickd
% Don't use device before ipcon is connected
% Make 2 second beep
pb.beep(2000);
input('Press key to exit\n', 's');
ipcon.disconnect();
end
|
Download (matlab_example_morse_code.m)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | function matlab_example_morse_code()
import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletPiezoBuzzer;
HOST = 'localhost';
PORT = 4223;
UID = 'XYZ'; % Change XYZ to the UID of your Piezo Buzzer Bricklet
ipcon = IPConnection(); % Create IP connection
pb = handle(BrickletPiezoBuzzer(UID, ipcon), 'CallbackProperties'); % Create device object
ipcon.connect(HOST, PORT); % Connect to brickd
% Don't use device before ipcon is connected
% Morse SOS
pb.morseCode('... --- ...');
input('Press key to exit\n', 's');
ipcon.disconnect();
end
|
Download (octave_example_beep.m)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | function octave_example_beep()
more off;
HOST = "localhost";
PORT = 4223;
UID = "XYZ"; % Change XYZ to the UID of your Piezo Buzzer Bricklet
ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
pb = javaObject("com.tinkerforge.BrickletPiezoBuzzer", UID, ipcon); % Create device object
ipcon.connect(HOST, PORT); % Connect to brickd
% Don't use device before ipcon is connected
% Make 2 second beep
pb.beep(2000);
input("Press key to exit\n", "s");
ipcon.disconnect();
end
|
Download (octave_example_morse_code.m)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | function octave_example_morse_code()
more off;
HOST = "localhost";
PORT = 4223;
UID = "XYZ"; % Change XYZ to the UID of your Piezo Buzzer Bricklet
ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
pb = javaObject("com.tinkerforge.BrickletPiezoBuzzer", UID, ipcon); % Create device object
ipcon.connect(HOST, PORT); % Connect to brickd
% Don't use device before ipcon is connected
% Morse SOS
pb.morseCode("... --- ...");
input("Press key to exit\n", "s");
ipcon.disconnect();
end
|
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.
BrickletPiezoBuzzer
(String uid, IPConnection ipcon)¶Parameters: |
|
---|---|
Returns: |
|
Creates an object with the unique device ID uid
.
In MATLAB:
import com.tinkerforge.BrickletPiezoBuzzer;
piezoBuzzer = BrickletPiezoBuzzer('YOUR_DEVICE_UID', ipcon);
In Octave:
piezoBuzzer = java_new("com.tinkerforge.BrickletPiezoBuzzer", "YOUR_DEVICE_UID", ipcon);
This object can then be used after the IP Connection is connected.
BrickletPiezoBuzzer.
beep
(long duration)¶Parameters: |
|
---|
Beeps for the given duration.
BrickletPiezoBuzzer.
morseCode
(String morse)¶Parameters: |
|
---|
Sets morse code that will be played by the piezo buzzer. The morse code is given as a string consisting of "." (dot), "-" (minus) and " " (space) for dits, dahs and pauses. Every other character is ignored.
For example: If you set the string "...---...", the piezo buzzer will beep nine times with the durations "short short short long long long short short short".
BrickletPiezoBuzzer.
getIdentity
()¶Return Object: |
|
---|
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.
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 my_callback(e)
fprintf('Parameter: %s\n', e.param);
end
set(device, 'ExampleCallback', @(h, e) my_callback(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 my_callback(e)
fprintf("Parameter: %s\n", e.param);
end
device.addExampleCallback(@my_callback);
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.
BrickletPiezoBuzzer.
BeepFinishedCallback
¶Event Object: |
|
---|
This callback is triggered if a beep set by beep()
is finished
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
addBeepFinishedCallback()
function. An added callback function can be removed with
the removeBeepFinishedCallback()
function.
BrickletPiezoBuzzer.
MorseCodeFinishedCallback
¶Event Object: |
|
---|
This callback is triggered if the playback of the morse code set by
morseCode()
is finished.
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
addMorseCodeFinishedCallback()
function. An added callback function can be removed with
the removeMorseCodeFinishedCallback()
function.
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.
BrickletPiezoBuzzer.
getAPIVersion
()¶Return Object: |
|
---|
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.
BrickletPiezoBuzzer.
getResponseExpected
(byte functionId)¶Parameters: |
|
---|---|
Returns: |
|
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:
BrickletPiezoBuzzer.
setResponseExpected
(byte functionId, boolean responseExpected)¶Parameters: |
|
---|
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 sent and errors are silently ignored, because they cannot be detected.
The following constants are available for this function:
For functionId:
BrickletPiezoBuzzer.
setResponseExpectedAll
(boolean responseExpected)¶Parameters: |
|
---|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
BrickletPiezoBuzzer.
DEVICE_IDENTIFIER
¶This constant is used to identify a Piezo Buzzer Bricklet.
The getIdentity()
function and the
IPConnection.EnumerateCallback
callback of the IP Connection have a deviceIdentifier
parameter to specify
the Brick's or Bricklet's type.
BrickletPiezoBuzzer.
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Piezo Buzzer Bricklet.