MATLAB/Octave - Segment Display 4x7 Bricklet 2.0

This is the description of the MATLAB/Octave API bindings for the Segment Display 4x7 Bricklet 2.0. General information and technical specifications for the Segment Display 4x7 Bricklet 2.0 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).

Numeric Value (MATLAB)

Download (matlab_example_numeric_value.m)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
function matlab_example_numeric_value()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletSegmentDisplay4x7V2;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your Segment Display 4x7 Bricklet 2.0

    ipcon = IPConnection(); % Create IP connection
    sd = handle(BrickletSegmentDisplay4x7V2(UID, ipcon), 'CallbackProperties'); % Create device object

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

    sd.setBrightness(7); % Set to full brightness

    % Show "- 42" on the Display
    sd.setNumericValue([-2 -1 4 2]);

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

Set Segments (MATLAB)

Download (matlab_example_set_segments.m)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
function matlab_example_set_segments()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletSegmentDisplay4x7V2;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your Segment Display 4x7 Bricklet 2.0

    ipcon = IPConnection(); % Create IP connection
    sd = handle(BrickletSegmentDisplay4x7V2(UID, ipcon), 'CallbackProperties'); % Create device object

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

    sd.setBrightness(7); % Set to full brightness

    % Activate all segments
    sd.setSegments([true true true true true true true true], ...
                   [true true true true true true true true], ...
                   [true true true true true true true true], ...
                   [true true true true true true true true], [true true], true);

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

Numeric Value (Octave)

Download (octave_example_numeric_value.m)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
function octave_example_numeric_value()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Segment Display 4x7 Bricklet 2.0

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    sd = javaObject("com.tinkerforge.BrickletSegmentDisplay4x7V2", UID, ipcon); % Create device object

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

    sd.setBrightness(7); % Set to full brightness

    % Show "- 42" on the Display
    sd.setNumericValue([-2 -1 4 2]);

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

Set Segments (Octave)

Download (octave_example_set_segments.m)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
function octave_example_set_segments()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Segment Display 4x7 Bricklet 2.0

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    sd = javaObject("com.tinkerforge.BrickletSegmentDisplay4x7V2", UID, ipcon); % Create device object

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

    sd.setBrightness(7); % Set to full brightness

    % Activate all segments
    sd.setSegments([true true true true true true true true], ...
                   [true true true true true true true true], ...
                   [true true true true true true true true], ...
                   [true true true true true true true true], [true true], true);

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

class BrickletSegmentDisplay4x7V2(String uid, IPConnection ipcon)
Parameters:
  • uid – Type: String
  • ipcon – Type: IPConnection
Returns:
  • segmentDisplay4x7V2 – Type: BrickletSegmentDisplay4x7V2

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletSegmentDisplay4x7V2;

segmentDisplay4x7V2 = BrickletSegmentDisplay4x7V2('YOUR_DEVICE_UID', ipcon);

In Octave:

segmentDisplay4x7V2 = java_new("com.tinkerforge.BrickletSegmentDisplay4x7V2", "YOUR_DEVICE_UID", ipcon);

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

void BrickletSegmentDisplay4x7V2.setSegments(boolean[] digit0, boolean[] digit1, boolean[] digit2, boolean[] digit3, boolean[] colon, boolean tick)
Parameters:
  • digit0 – Type: boolean[], Length: 8
  • digit1 – Type: boolean[], Length: 8
  • digit2 – Type: boolean[], Length: 8
  • digit3 – Type: boolean[], Length: 8
  • colon – Type: boolean[], Length: 2
  • tick – Type: boolean

Sets the segments of the Segment Display 4x7 Bricklet 2.0 segment-by-segment.

The data is split into the four digits, two colon dots and the tick mark.

The indices of the segments in the digit and colon parameters are as follows:

Indices of segments
BrickletSegmentDisplay4x7V2.Segments BrickletSegmentDisplay4x7V2.getSegments()
Return Object:
  • digit0 – Type: boolean[], Length: 8
  • digit1 – Type: boolean[], Length: 8
  • digit2 – Type: boolean[], Length: 8
  • digit3 – Type: boolean[], Length: 8
  • colon – Type: boolean[], Length: 2
  • tick – Type: boolean

Returns the segment data as set by setSegments().

void BrickletSegmentDisplay4x7V2.setBrightness(int brightness)
Parameters:
  • brightness – Type: int, Range: [0 to 7], Default: 7

The brightness can be set between 0 (dark) and 7 (bright).

int BrickletSegmentDisplay4x7V2.getBrightness()
Returns:
  • brightness – Type: int, Range: [0 to 7], Default: 7

Returns the brightness as set by setBrightness().

void BrickletSegmentDisplay4x7V2.setNumericValue(int[] value)
Parameters:
  • value – Type: int[], Length: 4, Range: [-2 to 15]

Sets a numeric value for each of the digits. They represent:

  • -2: minus sign
  • -1: blank
  • 0-9: 0-9
  • 10: A
  • 11: b
  • 12: C
  • 13: d
  • 14: E
  • 15: F

Example: A call with [-2, -1, 4, 2] will result in a display of "- 42".

void BrickletSegmentDisplay4x7V2.setSelectedSegment(int segment, boolean value)
Parameters:
  • segment – Type: int, Range: [0 to 31]
  • value – Type: boolean

Turns one specified segment on or off.

The indices of the segments are as follows:

Indices of selected segments
boolean BrickletSegmentDisplay4x7V2.getSelectedSegment(int segment)
Parameters:
  • segment – Type: int, Range: [0 to 31]
Returns:
  • value – Type: boolean

Returns the value of a single segment.

Advanced Functions

void BrickletSegmentDisplay4x7V2.startCounter(int valueFrom, int valueTo, int increment, long length)
Parameters:
  • valueFrom – Type: int, Range: [-999 to 9999]
  • valueTo – Type: int, Range: [-999 to 9999]
  • increment – Type: int, Range: [-999 to 9999]
  • length – Type: long, Unit: 1 ms, Range: [0 to 232 - 1]

Starts a counter with the from value that counts to the to value with the each step incremented by increment. length is the pause between each increment.

Example: If you set from to 0, to to 100, increment to 1 and length to 1000, a counter that goes from 0 to 100 with one second pause between each increment will be started.

Using a negative increment allows to count backwards.

You can stop the counter at every time by calling setSegments() or setNumericValue().

int BrickletSegmentDisplay4x7V2.getCounterValue()
Returns:
  • value – Type: int, Range: [-999 to 9999]

Returns the counter value that is currently shown on the display.

If there is no counter running a 0 will be returned.

BrickletSegmentDisplay4x7V2.SPITFPErrorCount BrickletSegmentDisplay4x7V2.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.

int BrickletSegmentDisplay4x7V2.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:

  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For status:

  • BrickletSegmentDisplay4x7V2.BOOTLOADER_STATUS_OK = 0
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_STATUS_CRC_MISMATCH = 5
int BrickletSegmentDisplay4x7V2.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:

  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletSegmentDisplay4x7V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
void BrickletSegmentDisplay4x7V2.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 BrickletSegmentDisplay4x7V2.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 BrickletSegmentDisplay4x7V2.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:

  • BrickletSegmentDisplay4x7V2.STATUS_LED_CONFIG_OFF = 0
  • BrickletSegmentDisplay4x7V2.STATUS_LED_CONFIG_ON = 1
  • BrickletSegmentDisplay4x7V2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletSegmentDisplay4x7V2.STATUS_LED_CONFIG_SHOW_STATUS = 3
int BrickletSegmentDisplay4x7V2.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:

  • BrickletSegmentDisplay4x7V2.STATUS_LED_CONFIG_OFF = 0
  • BrickletSegmentDisplay4x7V2.STATUS_LED_CONFIG_ON = 1
  • BrickletSegmentDisplay4x7V2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletSegmentDisplay4x7V2.STATUS_LED_CONFIG_SHOW_STATUS = 3
int BrickletSegmentDisplay4x7V2.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 BrickletSegmentDisplay4x7V2.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!

void BrickletSegmentDisplay4x7V2.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 BrickletSegmentDisplay4x7V2.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.

BrickletSegmentDisplay4x7V2.Identity BrickletSegmentDisplay4x7V2.getIdentity()
Return Object:
  • uid – Type: String, Length: up to 8
  • connectedUid – Type: String, Length: up to 8
  • position – Type: char, Range: ['a' to 'h', 'i', 'z']
  • hardwareVersion – Type: int[], Length: 3
    • 1: major – Type: int, Range: [0 to 255]
    • 2: minor – Type: int, Range: [0 to 255]
    • 3: revision – Type: int, Range: [0 to 255]
  • firmwareVersion – Type: int[], Length: 3
    • 1: major – Type: int, Range: [0 to 255]
    • 2: minor – Type: int, Range: [0 to 255]
    • 3: revision – Type: int, 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). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as position 'z'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

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 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.

callback BrickletSegmentDisplay4x7V2.CounterFinishedCallback
Event Object:
  • empty object

This callback is triggered when the counter (see startCounter()) 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 addCounterFinishedCallback() function. An added callback function can be removed with the removeCounterFinishedCallback() function.

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.

int[] BrickletSegmentDisplay4x7V2.getAPIVersion()
Return Object:
  • apiVersion – Type: int[], Length: 3
    • 1: major – Type: int, Range: [0 to 255]
    • 2: minor – Type: int, Range: [0 to 255]
    • 3: revision – Type: int, 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 BrickletSegmentDisplay4x7V2.getResponseExpected(int functionId)
Parameters:
  • functionId – Type: int, 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 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.

The following constants are available for this function:

For functionId:

  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_SEGMENTS = 1
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_BRIGHTNESS = 3
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_NUMERIC_VALUE = 5
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_SELECTED_SEGMENT = 6
  • BrickletSegmentDisplay4x7V2.FUNCTION_START_COUNTER = 8
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletSegmentDisplay4x7V2.FUNCTION_RESET = 243
  • BrickletSegmentDisplay4x7V2.FUNCTION_WRITE_UID = 248
void BrickletSegmentDisplay4x7V2.setResponseExpected(int functionId, boolean responseExpected)
Parameters:
  • functionId – Type: int, 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 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 constants are available for this function:

For functionId:

  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_SEGMENTS = 1
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_BRIGHTNESS = 3
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_NUMERIC_VALUE = 5
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_SELECTED_SEGMENT = 6
  • BrickletSegmentDisplay4x7V2.FUNCTION_START_COUNTER = 8
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletSegmentDisplay4x7V2.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletSegmentDisplay4x7V2.FUNCTION_RESET = 243
  • BrickletSegmentDisplay4x7V2.FUNCTION_WRITE_UID = 248
void BrickletSegmentDisplay4x7V2.setResponseExpectedAll(boolean responseExpected)
Parameters:
  • responseExpected – Type: boolean

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

Constants

int BrickletSegmentDisplay4x7V2.DEVICE_IDENTIFIER

This constant is used to identify a Segment Display 4x7 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.

String BrickletSegmentDisplay4x7V2.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Segment Display 4x7 Bricklet 2.0.