Module com.pi4j.crowpi

Package com.pi4j.crowpi.components

Class SevenSegmentComponent

java.lang.Object

com.pi4j.crowpi.components.Component

com.pi4j.crowpi.components.internal.HT16K33

com.pi4j.crowpi.components.SevenSegmentComponent

public class SevenSegmentComponent
extends HT16K33

Implementation of the CrowPi seven-segment display using I2C with Pi4J

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	SevenSegmentComponent.Segment	Mapping of segments to their respective bit according to the HT16K33.

Field Summary

Fields

Modifier and Type	Field	Description
protected static final Map<Character,Byte>	CHAR_BITSETS	Mapping of characters to their respective byte representation.
protected static final int	DEFAULT_BUS	Default I2C bus address for the seven-segment display on the CrowPi
protected static final int	DEFAULT_DEVICE	Default I2C device address for the seven-segment display on the CrowPi

Fields inherited from class com.pi4j.crowpi.components.internal.HT16K33

buffer, i2c

Fields inherited from class com.pi4j.crowpi.components.Component

logger

Constructor Summary

Constructors

Constructor	Description
SevenSegmentComponent(com.pi4j.context.Context pi4j)	Creates a new seven-segment display component with the default bus and device address.
SevenSegmentComponent(com.pi4j.context.Context pi4j, int bus, int device)	Creates a new seven-segment display component with a custom bus and device address.

Method Summary

Modifier and Type	Method	Description
protected static byte	fromSegments(SevenSegmentComponent.Segment... segments)	Helper method for creating a raw digit value (byte) from 0-n segments.
protected com.pi4j.io.i2c.I2C	getI2C()	Returns the created I2C instance for the seven-segment display
protected byte	getRawDigit(int position)	Gets the raw digit at the specified position.
void	print(double d)	Prints the given double value to the seven-segment display, automatically setting the decimal point if applicable.
void	print(int i)	Prints the given integer value to the seven-segment display.
void	print(String s)	Prints the first four letters (or less if applicable) of the given string to the display.
void	print(LocalTime time)	Prints the hours and minutes of the given LocalTime instance to the seven-segment display.
void	setColon(boolean enabled)	Enables or disables the colon symbol of the seven-segment display.
void	setDecimalPoint(int position, boolean enabled)	Enables or disables the decimal point at the given digit position.
void	setDigit(int position, char c)	Sets the digit at the specified position to the given character.
void	setDigit(int position, int i)	Sets the digit at the specified position to the given integer.
void	setDigit(int position, SevenSegmentComponent.Segment... segments)	Sets the digit at the specified position to match the given segments.
protected void	setRawDigit(int position, byte value)	Sets the raw digit at the specified position.

Methods inherited from class com.pi4j.crowpi.components.internal.HT16K33

clear, refresh, setBlinkRate, setBrightness, setEnabled

Methods inherited from class com.pi4j.crowpi.components.Component

sleep, triggerSimpleEvent

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_BUS

protected static final int DEFAULT_BUS

Default I2C bus address for the seven-segment display on the CrowPi

See Also:

• Constant Field Values

DEFAULT_DEVICE

protected static final int DEFAULT_DEVICE

Default I2C device address for the seven-segment display on the CrowPi

See Also:

• Constant Field Values

CHAR_BITSETS

protected static final Map<Character,Byte> CHAR_BITSETS

Mapping of characters to their respective byte representation. Each byte is a bitset where each bit specifies if a specific segment should be enabled (1) or disabled (0).

Constructor Details

SevenSegmentComponent

public SevenSegmentComponent(com.pi4j.context.Context pi4j)

Creates a new seven-segment display component with the default bus and device address.

Parameters:

pi4j - Pi4J context

SevenSegmentComponent

public SevenSegmentComponent(com.pi4j.context.Context pi4j,
 int bus,
 int device)

Creates a new seven-segment display component with a custom bus and device address.

Parameters:

pi4j - Pi4J context

bus - Bus address

device - Device address

Method Details

print

public void print(int i)

Prints the given integer value to the seven-segment display. This works by converting the integer into a string and passing it to print(String). Please note that due to the limitations of the display only the first four digits will be displayed. This will clear the buffer and automatically call HT16K33.refresh() afterwards to immediately display the number.

Parameters:

i - Integer to display

print

public void print(double d)

Prints the given double value to the seven-segment display, automatically setting the decimal point if applicable. This works by converting the double into a string and passing it to print(String). Please note that due to the limitations of the display only the first four digits will be displayed. This will clear the buffer and automatically call HT16K33.refresh() afterwards to immediately display the number.

Parameters:

d - Double to display

print

public void print(LocalTime time)

Prints the hours and minutes of the given LocalTime instance to the seven-segment display. The time will be displayed in 24 hours format as HH:MM with the colon being active for every odd second. This will clear the buffer and automatically call HT16K33.refresh() afterwards to immediately display the time.

Parameters:

time - Time to display

print

public void print(String s)

Prints the first four letters (or less if applicable) of the given string to the display. Additional letters are ignored. Adding a dot after a digit or putting a colon after two digits causes the respective symbols to be displayed too. This will clear the buffer and automatically call HT16K33.refresh() afterwards to immediately display the text.

Example: "1.2:34." will print the string "1234" to the display, with decimal point #1 and #4 as well as the colon symbol being set

Parameters:

s - String which should be printed

setColon

public void setColon(boolean enabled)

Enables or disables the colon symbol of the seven-segment display. This will only affect the internal buffer and does not get displayed until HT16K33.refresh() gets called.

Parameters:

enabled - Specify if colon should be enabled or disabled.

setDecimalPoint

public void setDecimalPoint(int position,
 boolean enabled)

Enables or disables the decimal point at the given digit position. Please note that the decimal point is just an additional belonging to the same digit. This means that overriding the specific digit (e.g. using setRawDigit(int, byte) will reset the decimal point. This will only affect the internal buffer and does not get displayed until HT16K33.refresh() gets called.

Parameters:

position - Desired position of digit from 0-3.

enabled - Specify if decimal point should be enabled or disabled.

setDigit

public void setDigit(int position,
 int i)

Sets the digit at the specified position to the given integer. The integer must not contain more than one number, in other words it has to be in the range 0-9. This will only affect the internal buffer and does not get displayed until HT16K33.refresh() gets called.

Parameters:

position - Desired position of digit from 0-3.

i - Single digit number which should be displayed.

setDigit

public void setDigit(int position,
 char c)

Sets the digit at the specified position to the given character. The character must be representable by the seven-segment display, so only a subset of chars is supported. This will only affect the internal buffer and does not get displayed until HT16K33.refresh() gets called.

Parameters:

position - Desired position of digit from 0-3.

c - Character which should be displayed.

setDigit

public void setDigit(int position,
 SevenSegmentComponent.Segment... segments)

Sets the digit at the specified position to match the given segments. This will only affect the internal buffer and does not get displayed until HT16K33.refresh() gets called.

Parameters:

position - Desired position of digit from 0-3.

segments - Segments which should be displayed.

setRawDigit

protected void setRawDigit(int position,
 byte value)

Sets the raw digit at the specified position. This method will take a byte value which gets processed by the underlying chip. The byte represents a bitset where each bit belongs to a specific segment and decides if its enabled (1) or disabled (0). Valid values can be crafted using the fromSegments(Segment...) method. This will only affect the internal buffer and does not get displayed until HT16K33.refresh() gets called.

Parameters:

position - Desired position of digit from 0-3.

value - Raw byte value to be displayed.

getRawDigit

protected byte getRawDigit(int position)

Gets the raw digit at the specified position. This method will return the internal byte value of the underlying chip. The byte represents a bitset where each bit belongs to a specific segment and decides if its enabled (1) or disabled (0).

Parameters:

position - Desired position of digit from 0-3.

Returns:

Raw byte value at specified position.

getI2C

protected com.pi4j.io.i2c.I2C getI2C()

Returns the created I2C instance for the seven-segment display

Returns:

I2C instance

fromSegments

protected static byte fromSegments(SevenSegmentComponent.Segment... segments)

Helper method for creating a raw digit value (byte) from 0-n segments. This can be used together with the SevenSegmentComponent.Segment enumeration to create and display your own digits. All segments passed to this method will be flagged as active and enabled when passed to setRawDigit(int, byte)

Parameters:

segments - Segments which should be enabled to together

Returns:

Raw digit value as byte