This is the description of the MATLAB/Octave API bindings for the Hall Effect Bricklet 2.0. General information and technical specifications for the Hall Effect Bricklet 2.0 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_counter.m)
1function matlab_example_counter()
2 import com.tinkerforge.IPConnection;
3 import com.tinkerforge.BrickletHallEffectV2;
4
5 HOST = 'localhost';
6 PORT = 4223;
7 UID = 'XYZ'; % Change XYZ to the UID of your Hall Effect Bricklet 2.0
8
9 ipcon = IPConnection(); % Create IP connection
10 he = handle(BrickletHallEffectV2(UID, ipcon), 'CallbackProperties'); % Create device object
11
12 ipcon.connect(HOST, PORT); % Connect to brickd
13 % Don't use device before ipcon is connected
14
15 % Get current count without counter reset
16 count = he.getCounter(false);
17 fprintf('Count: %i\n', count);
18
19 input('Press key to exit\n', 's');
20 ipcon.disconnect();
21end
Download (matlab_example_magnetic_flux_density.m)
1function matlab_example_magnetic_flux_density()
2 import com.tinkerforge.IPConnection;
3 import com.tinkerforge.BrickletHallEffectV2;
4
5 HOST = 'localhost';
6 PORT = 4223;
7 UID = 'XYZ'; % Change XYZ to the UID of your Hall Effect Bricklet 2.0
8
9 ipcon = IPConnection(); % Create IP connection
10 he = handle(BrickletHallEffectV2(UID, ipcon), 'CallbackProperties'); % Create device object
11
12 ipcon.connect(HOST, PORT); % Connect to brickd
13 % Don't use device before ipcon is connected
14
15 % Get current Magnetic Flux Density
16 magneticFluxDensity = he.getMagneticFluxDensity();
17 fprintf('Magnetic Flux Density: %i µT\n', magneticFluxDensity);
18
19 input('Press key to exit\n', 's');
20 ipcon.disconnect();
21end
Download (matlab_example_counter_callback.m)
1function matlab_example_counter_callback()
2 import com.tinkerforge.IPConnection;
3 import com.tinkerforge.BrickletHallEffectV2;
4
5 HOST = 'localhost';
6 PORT = 4223;
7 UID = 'XYZ'; % Change XYZ to the UID of your Hall Effect Bricklet 2.0
8
9 ipcon = IPConnection(); % Create IP connection
10 he = handle(BrickletHallEffectV2(UID, ipcon), 'CallbackProperties'); % Create device object
11
12 ipcon.connect(HOST, PORT); % Connect to brickd
13 % Don't use device before ipcon is connected
14
15 % Configure counter with ±3000µT threshold and 10ms debounce
16 he.setCounterConfig(3000, -3000, 10000);
17
18 % Register counter callback to function cb_counter
19 set(he, 'CounterCallback', @(h, e) cb_counter(e));
20
21 % Set period for counter callback to 0.1s (100ms)
22 he.setCounterCallbackConfiguration(100, true);
23
24 input('Press key to exit\n', 's');
25 ipcon.disconnect();
26end
27
28% Callback function for counter callback
29function cb_counter(e)
30 fprintf('Counter: %i\n', e.counter);
31end
Download (octave_example_magnetic_flux_density.m)
1function octave_example_magnetic_flux_density()
2 more off;
3
4 HOST = "localhost";
5 PORT = 4223;
6 UID = "XYZ"; % Change XYZ to the UID of your Hall Effect Bricklet 2.0
7
8 ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
9 he = javaObject("com.tinkerforge.BrickletHallEffectV2", UID, ipcon); % Create device object
10
11 ipcon.connect(HOST, PORT); % Connect to brickd
12 % Don't use device before ipcon is connected
13
14 % Get current Magnetic Flux Density
15 magneticFluxDensity = he.getMagneticFluxDensity();
16 fprintf("Magnetic Flux Density: %d µT\n", magneticFluxDensity);
17
18 input("Press key to exit\n", "s");
19 ipcon.disconnect();
20end
Download (octave_example_counter.m)
1function octave_example_counter()
2 more off;
3
4 HOST = "localhost";
5 PORT = 4223;
6 UID = "XYZ"; % Change XYZ to the UID of your Hall Effect Bricklet 2.0
7
8 ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
9 he = javaObject("com.tinkerforge.BrickletHallEffectV2", UID, ipcon); % Create device object
10
11 ipcon.connect(HOST, PORT); % Connect to brickd
12 % Don't use device before ipcon is connected
13
14 % Get current count without counter reset
15 count = he.getCounter(false);
16 fprintf("Count: %d\n", java2int(count));
17
18 input("Press key to exit\n", "s");
19 ipcon.disconnect();
20end
21
22function int = java2int(value)
23 if compare_versions(version(), "3.8", "<=")
24 int = value.intValue();
25 else
26 int = value;
27 end
28end
Download (octave_example_counter_callback.m)
1function octave_example_counter_callback()
2 more off;
3
4 HOST = "localhost";
5 PORT = 4223;
6 UID = "XYZ"; % Change XYZ to the UID of your Hall Effect Bricklet 2.0
7
8 ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
9 he = javaObject("com.tinkerforge.BrickletHallEffectV2", UID, ipcon); % Create device object
10
11 ipcon.connect(HOST, PORT); % Connect to brickd
12 % Don't use device before ipcon is connected
13
14 % Configure counter with ±3000µT threshold and 10ms debounce
15 he.setCounterConfig(3000, -3000, 10000);
16
17 % Register counter callback to function cb_counter
18 he.addCounterCallback(@cb_counter);
19
20 % Set period for counter callback to 0.1s (100ms)
21 he.setCounterCallbackConfiguration(100, true);
22
23 input("Press key to exit\n", "s");
24 ipcon.disconnect();
25end
26
27% Callback function for counter callback
28function cb_counter(e)
29 fprintf("Counter: %d\n", java2int(e.counter));
30end
31
32function int = java2int(value)
33 if compare_versions(version(), "3.8", "<=")
34 int = value.intValue();
35 else
36 int = value;
37 end
38end
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.
| Parameters: |
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|---|---|
| Returns: |
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Creates an object with the unique device ID uid.
In MATLAB:
import com.tinkerforge.BrickletHallEffectV2;
hallEffectV2 = BrickletHallEffectV2('YOUR_DEVICE_UID', ipcon);
In Octave:
hallEffectV2 = java_new("com.tinkerforge.BrickletHallEffectV2", "YOUR_DEVICE_UID", ipcon);
This object can then be used after the IP Connection is connected.
| Returns: |
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|---|
Returns the magnetic flux density (magnetic induction).
If you want to get the value periodically, it is recommended to use the
MagneticFluxDensityCallback callback. You can set the callback configuration
with setMagneticFluxDensityCallbackConfiguration().
| Parameters: |
|
|---|---|
| Returns: |
|
Returns the current value of the counter.
You can configure the low/high thresholds and the debounce time
with setCounterConfig().
If you set reset counter to true, the count is set back to 0 directly after it is read.
If you want to get the count periodically, it is recommended to use the
CounterCallback callback. You can set the callback configuration
with setCounterCallbackConfiguration().
| Parameters: |
|
|---|
Sets a high and a low threshold as well as a debounce time.
If the measured magnetic flux density goes above the high threshold or below the low threshold, the count of the counter is increased by 1.
The debounce time is the minimum time between two count increments.
| Return Object: |
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|---|
Returns the counter config as set by setCounterConfig().
| Return Object: |
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|---|
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.
| Parameters: |
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|---|
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:
For config:
BrickletHallEffectV2.STATUS_LED_CONFIG_OFF = 0
BrickletHallEffectV2.STATUS_LED_CONFIG_ON = 1
BrickletHallEffectV2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
BrickletHallEffectV2.STATUS_LED_CONFIG_SHOW_STATUS = 3
| Returns: |
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|---|
Returns the configuration as set by setStatusLEDConfig()
The following constants are available for this function:
For config:
BrickletHallEffectV2.STATUS_LED_CONFIG_OFF = 0
BrickletHallEffectV2.STATUS_LED_CONFIG_ON = 1
BrickletHallEffectV2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
BrickletHallEffectV2.STATUS_LED_CONFIG_SHOW_STATUS = 3
| Returns: |
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|---|
Returns the temperature 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.
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!
| 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.
| Parameters: |
|
|---|
The period is the period with which the MagneticFluxDensityCallback 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 MagneticFluxDensityCallback 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 following constants are available for this function:
For option:
BrickletHallEffectV2.THRESHOLD_OPTION_OFF = 'x'
BrickletHallEffectV2.THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletHallEffectV2.THRESHOLD_OPTION_INSIDE = 'i'
BrickletHallEffectV2.THRESHOLD_OPTION_SMALLER = '<'
BrickletHallEffectV2.THRESHOLD_OPTION_GREATER = '>'
| Return Object: |
|
|---|
Returns the callback configuration as set by setMagneticFluxDensityCallbackConfiguration().
The following constants are available for this function:
For option:
BrickletHallEffectV2.THRESHOLD_OPTION_OFF = 'x'
BrickletHallEffectV2.THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletHallEffectV2.THRESHOLD_OPTION_INSIDE = 'i'
BrickletHallEffectV2.THRESHOLD_OPTION_SMALLER = '<'
BrickletHallEffectV2.THRESHOLD_OPTION_GREATER = '>'
| Parameters: |
|
|---|
The period is the period with which the CounterCallback
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 at least one of the values has changed. If the values 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.
| Return Object: |
|
|---|
Returns the callback configuration as set by
setCounterCallbackConfiguration().
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.
| Event Object: |
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|---|
This callback is triggered periodically according to the configuration set by
setMagneticFluxDensityCallbackConfiguration().
The parameter is the same as getMagneticFluxDensity().
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
addMagneticFluxDensityCallback() function. An added callback function can be removed with
the removeMagneticFluxDensityCallback() function.
| Event Object: |
|
|---|
This callback is triggered periodically according to the configuration set by
setCounterCallbackConfiguration().
The count is the same as you would get with getCounter().
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
addCounterCallback() function. An added callback function can be removed with
the removeCounterCallback() 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.
| 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.
| Parameters: |
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|---|---|
| Returns: |
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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:
BrickletHallEffectV2.FUNCTION_SET_MAGNETIC_FLUX_DENSITY_CALLBACK_CONFIGURATION = 2
BrickletHallEffectV2.FUNCTION_SET_COUNTER_CONFIG = 6
BrickletHallEffectV2.FUNCTION_SET_COUNTER_CALLBACK_CONFIGURATION = 8
BrickletHallEffectV2.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
BrickletHallEffectV2.FUNCTION_SET_STATUS_LED_CONFIG = 239
BrickletHallEffectV2.FUNCTION_RESET = 243
BrickletHallEffectV2.FUNCTION_WRITE_UID = 248
| 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:
BrickletHallEffectV2.FUNCTION_SET_MAGNETIC_FLUX_DENSITY_CALLBACK_CONFIGURATION = 2
BrickletHallEffectV2.FUNCTION_SET_COUNTER_CONFIG = 6
BrickletHallEffectV2.FUNCTION_SET_COUNTER_CALLBACK_CONFIGURATION = 8
BrickletHallEffectV2.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
BrickletHallEffectV2.FUNCTION_SET_STATUS_LED_CONFIG = 239
BrickletHallEffectV2.FUNCTION_RESET = 243
BrickletHallEffectV2.FUNCTION_WRITE_UID = 248
| Parameters: |
|
|---|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.
| Parameters: |
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|---|---|
| Returns: |
|
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:
For mode:
BrickletHallEffectV2.BOOTLOADER_MODE_BOOTLOADER = 0
BrickletHallEffectV2.BOOTLOADER_MODE_FIRMWARE = 1
BrickletHallEffectV2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
BrickletHallEffectV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
BrickletHallEffectV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
For status:
BrickletHallEffectV2.BOOTLOADER_STATUS_OK = 0
BrickletHallEffectV2.BOOTLOADER_STATUS_INVALID_MODE = 1
BrickletHallEffectV2.BOOTLOADER_STATUS_NO_CHANGE = 2
BrickletHallEffectV2.BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
BrickletHallEffectV2.BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
BrickletHallEffectV2.BOOTLOADER_STATUS_CRC_MISMATCH = 5
| Returns: |
|
|---|
Returns the current bootloader mode, see setBootloaderMode().
The following constants are available for this function:
For mode:
BrickletHallEffectV2.BOOTLOADER_MODE_BOOTLOADER = 0
BrickletHallEffectV2.BOOTLOADER_MODE_FIRMWARE = 1
BrickletHallEffectV2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
BrickletHallEffectV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
BrickletHallEffectV2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
| Parameters: |
|
|---|
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.
| Parameters: |
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|---|---|
| Returns: |
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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.
| Parameters: |
|
|---|
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.
| Returns: |
|
|---|
Returns the current UID as an integer. Encode as Base58 to get the usual string version.
This constant is used to identify a Hall Effect Bricklet 2.0.
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.
This constant represents the human readable name of a Hall Effect Bricklet 2.0.