Java - Hall Effect Bricklet 2.0

This is the description of the Java 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 Java API bindings is part of their general description.

Examples

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

Counter

Download (ExampleCounter.java)

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import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletHallEffectV2;

public class ExampleCounter {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;

    // Change XYZ to the UID of your Hall Effect Bricklet 2.0
    private static final String UID = "XYZ";

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions
    //       you might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletHallEffectV2 he = new BrickletHallEffectV2(UID, ipcon); // Create device object

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

        // Get current count without counter reset
        long count = he.getCounter(false); // Can throw com.tinkerforge.TimeoutException
        System.out.println("Count: " + count);

        System.out.println("Press key to exit"); System.in.read();
        ipcon.disconnect();
    }
}

Magnetic Flux Density

Download (ExampleMagneticFluxDensity.java)

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import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletHallEffectV2;

public class ExampleMagneticFluxDensity {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;

    // Change XYZ to the UID of your Hall Effect Bricklet 2.0
    private static final String UID = "XYZ";

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions
    //       you might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletHallEffectV2 he = new BrickletHallEffectV2(UID, ipcon); // Create device object

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

        // Get current Magnetic Flux Density
        int magneticFluxDensity = he.getMagneticFluxDensity(); // Can throw com.tinkerforge.TimeoutException
        System.out.println("Magnetic Flux Density: " + magneticFluxDensity + " µT");

        System.out.println("Press key to exit"); System.in.read();
        ipcon.disconnect();
    }
}

Counter Callback

Download (ExampleCounterCallback.java)

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import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletHallEffectV2;

public class ExampleCounterCallback {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;

    // Change XYZ to the UID of your Hall Effect Bricklet 2.0
    private static final String UID = "XYZ";

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions
    //       you might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletHallEffectV2 he = new BrickletHallEffectV2(UID, ipcon); // Create device object

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

        // Configure counter with ±3000µT threshold and 10ms debounce
        he.setCounterConfig(3000, -3000, 10000);

        // Add counter listener
        he.addCounterListener(new BrickletHallEffectV2.CounterListener() {
            public void counter(long counter) {
                System.out.println("Counter: " + counter);
            }
        });

        // Set period for counter callback to 0.1s (100ms)
        he.setCounterCallbackConfiguration(100, true);

        System.out.println("Press key to exit"); System.in.read();
        ipcon.disconnect();
    }
}

API

Generally, every method of the Java 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 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

class BrickletHallEffectV2(String uid, IPConnection ipcon)
Parameters:
  • uid – Type: String
  • ipcon – Type: IPConnection
Returns:
  • hallEffectV2 – Type: BrickletHallEffectV2

Creates an object with the unique device ID uid:

BrickletHallEffectV2 hallEffectV2 = new BrickletHallEffectV2("YOUR_DEVICE_UID", ipcon);

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

int BrickletHallEffectV2.getMagneticFluxDensity()
Returns:
  • magneticFluxDensity – Type: int, Unit: 1 µT, Range: [-7000 to 7000]

Returns the magnetic flux density (magnetic induction).

If you want to get the value periodically, it is recommended to use the MagneticFluxDensityListener listener. You can set the listener configuration with setMagneticFluxDensityCallbackConfiguration().

long BrickletHallEffectV2.getCounter(boolean resetCounter)
Parameters:
  • resetCounter – Type: boolean
Returns:
  • count – Type: long, Range: [0 to 232 - 1]

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 CounterListener listener. You can set the listener configuration with setCounterCallbackConfiguration().

void BrickletHallEffectV2.setCounterConfig(int highThreshold, int lowThreshold, long debounce)
Parameters:
  • highThreshold – Type: int, Unit: 1 µT, Range: [-215 to 215 - 1], Default: 2000
  • lowThreshold – Type: int, Unit: 1 µT, Range: [-215 to 215 - 1], Default: -2000
  • debounce – Type: long, Unit: 1 µs, Range: [0 to 1000000], Default: 100000

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.

BrickletHallEffectV2.CounterConfig BrickletHallEffectV2.getCounterConfig()
Return Object:
  • highThreshold – Type: int, Unit: 1 µT, Range: [-215 to 215 - 1], Default: 2000
  • lowThreshold – Type: int, Unit: 1 µT, Range: [-215 to 215 - 1], Default: -2000
  • debounce – Type: long, Unit: 1 µs, Range: [0 to 1000000], Default: 100000

Returns the counter config as set by setCounterConfig().

Advanced Functions

BrickletHallEffectV2.SPITFPErrorCount BrickletHallEffectV2.getSPITFPErrorCount()
Return Object:
  • errorCountAckChecksum – Type: long, Range: [0 to 232 - 1]
  • errorCountMessageChecksum – Type: long, Range: [0 to 232 - 1]
  • errorCountFrame – Type: long, Range: [0 to 232 - 1]
  • errorCountOverflow – Type: long, Range: [0 to 232 - 1]

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.

void BrickletHallEffectV2.setStatusLEDConfig(int config)
Parameters:
  • config – Type: int, Range: See constants, Default: 3

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
int BrickletHallEffectV2.getStatusLEDConfig()
Returns:
  • config – Type: int, Range: See constants, Default: 3

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
int BrickletHallEffectV2.getChipTemperature()
Returns:
  • temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

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.

void BrickletHallEffectV2.reset()

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!

BrickletHallEffectV2.Identity BrickletHallEffectV2.getIdentity()
Return Object:
  • uid – Type: String, Length: up to 8
  • connectedUid – Type: String, Length: up to 8
  • position – Type: char, Range: ['a' to 'h', 'z']
  • hardwareVersion – Type: short[], Length: 3
    • 0: major – Type: short, Range: [0 to 255]
    • 1: minor – Type: short, Range: [0 to 255]
    • 2: revision – Type: short, Range: [0 to 255]
  • firmwareVersion – Type: short[], Length: 3
    • 0: major – Type: short, Range: [0 to 255]
    • 1: minor – Type: short, Range: [0 to 255]
    • 2: revision – Type: short, Range: [0 to 255]
  • deviceIdentifier – Type: int, 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.

Listener Configuration Functions

void BrickletHallEffectV2.setMagneticFluxDensityCallbackConfiguration(long period, boolean valueHasToChange, char option, int min, int max)
Parameters:
  • period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: int, Unit: 1 µT, Range: [-215 to 215 - 1], Default: 0
  • max – Type: int, Unit: 1 µT, Range: [-215 to 215 - 1], Default: 0

The period is the period with which the MagneticFluxDensityListener listener is triggered periodically. A value of 0 turns the listener off.

If the value has to change-parameter is set to true, the listener is only triggered after the value has changed. If the value didn't change within the period, the listener is triggered immediately on change.

If it is set to false, the listener is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the listener with thresholds.

The option-parameter together with min/max sets a threshold for the MagneticFluxDensityListener listener.

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 listener 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 = '>'
BrickletHallEffectV2.MagneticFluxDensityCallbackConfiguration BrickletHallEffectV2.getMagneticFluxDensityCallbackConfiguration()
Return Object:
  • period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false
  • option – Type: char, Range: See constants, Default: 'x'
  • min – Type: int, Unit: 1 µT, Range: [-215 to 215 - 1], Default: 0
  • max – Type: int, Unit: 1 µT, Range: [-215 to 215 - 1], Default: 0

Returns the listener 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 = '>'
void BrickletHallEffectV2.setCounterCallbackConfiguration(long period, boolean valueHasToChange)
Parameters:
  • period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false

The period is the period with which the CounterListener listener is triggered periodically. A value of 0 turns the listener off.

If the value has to change-parameter is set to true, the listener is only triggered after at least one of the values has changed. If the values didn't change within the period, the listener is triggered immediately on change.

If it is set to false, the listener is continuously triggered with the period, independent of the value.

BrickletHallEffectV2.CounterCallbackConfiguration BrickletHallEffectV2.getCounterCallbackConfiguration()
Return Object:
  • period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • valueHasToChange – Type: boolean, Default: false

Returns the listener configuration as set by setCounterCallbackConfiguration().

Listeners

Listeners can be registered to receive time critical or recurring data from the device. The registration is done with add*Listener() functions of the device object.

The parameter is a listener class object, for example:

device.addExampleListener(new BrickletHallEffectV2.ExampleListener() {
    public void property(int value) {
        System.out.println("Value: " + value);
    }
});

The available listener classes with inherent methods to be overwritten are described below. It is possible to add several listeners and to remove them with the corresponding remove*Listener() function.

Note

Using listeners 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.

class BrickletHallEffectV2.MagneticFluxDensityListener()

This listener can be added with the addMagneticFluxDensityListener() function. An added listener can be removed with the removeMagneticFluxDensityListener() function.

void magneticFluxDensity(int magneticFluxDensity)
Parameters:
  • magneticFluxDensity – Type: int, Unit: 1 µT, Range: [-7000 to 7000]

This listener is triggered periodically according to the configuration set by setMagneticFluxDensityCallbackConfiguration().

The parameter is the same as getMagneticFluxDensity().

class BrickletHallEffectV2.CounterListener()

This listener can be added with the addCounterListener() function. An added listener can be removed with the removeCounterListener() function.

void counter(long count)
Parameters:
  • count – Type: long, Range: [0 to 232 - 1]

This listener is triggered periodically according to the configuration set by setCounterCallbackConfiguration().

The count is the same as you would get with getCounter().

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.

short[] BrickletHallEffectV2.getAPIVersion()
Return Object:
  • apiVersion – Type: short[], Length: 3
    • 0: major – Type: short, Range: [0 to 255]
    • 1: minor – Type: short, Range: [0 to 255]
    • 2: revision – Type: short, 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.

boolean BrickletHallEffectV2.getResponseExpected(byte functionId)
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 listener 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
void BrickletHallEffectV2.setResponseExpected(byte functionId, boolean responseExpected)
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 listener 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
void BrickletHallEffectV2.setResponseExpectedAll(boolean responseExpected)
Parameters:
  • responseExpected – Type: boolean

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

Internal Functions

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.

int BrickletHallEffectV2.setBootloaderMode(int mode)
Parameters:
  • mode – Type: int, Range: See constants
Returns:
  • status – Type: int, Range: See constants

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
int BrickletHallEffectV2.getBootloaderMode()
Returns:
  • mode – Type: int, Range: See constants

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
void BrickletHallEffectV2.setWriteFirmwarePointer(long pointer)
Parameters:
  • pointer – Type: long, Unit: 1 B, Range: [0 to 232 - 1]

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.

int BrickletHallEffectV2.writeFirmware(int[] data)
Parameters:
  • data – Type: int[], Length: 64, Range: [0 to 255]
Returns:
  • status – Type: int, Range: [0 to 255]

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.

void BrickletHallEffectV2.writeUID(long uid)
Parameters:
  • uid – Type: long, Range: [0 to 232 - 1]

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.

long BrickletHallEffectV2.readUID()
Returns:
  • uid – Type: long, Range: [0 to 232 - 1]

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

Constants

int BrickletHallEffectV2.DEVICE_IDENTIFIER

This constant is used to identify a Hall Effect Bricklet 2.0.

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

String BrickletHallEffectV2.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Hall Effect Bricklet 2.0.