public interface Serial extends SerialDataReader, SerialDataWriter, AutoCloseable
This interface provides a set of functions for 'Serial' communication.
Before using the Pi4J library, you need to ensure that the Java VM in configured with access to the following system libraries:
This library depends on the wiringPi native system library. (developed by Gordon Henderson @ http://wiringpi.com/)
SerialFactory
,
SerialDataEvent
,
SerialDataEventListener
,
https://www.pi4j.com/Modifier and Type | Field and Description |
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static String |
DEFAULT_COM_PORT
The default hardware COM port provided via the Raspberry Pi GPIO header.
|
static String |
FIRST_USB_COM_PORT |
static String |
SECOND_USB_COM_PORT |
Modifier and Type | Method and Description |
---|---|
void |
addListener(SerialDataEventListener... listener)
Java consumer code can call this method to register itself as a listener for serial data
events.
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void |
close()
This method is called to close a currently open open serial port.
|
void |
discardAll()
Discards any data in both the serial receive and transmit buffers.
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void |
discardInput()
Discards any data in the serial receive (input) buffer.
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void |
discardOutput()
Discards any data in the serial transmit (output) buffer.
|
void |
flush()
Forces the transmission of any remaining data in the serial port transmit buffer.
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boolean |
getCD()
Get the CD (carrier-detect) pin state.
|
boolean |
getCTS()
Get the CTS (clean-to-send) pin state.
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boolean |
getDSR()
Get the DSR (data-set-ready) pin state.
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boolean |
getDTR()
Get the DTR (data-terminal-ready) pin state.
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int |
getFileDescriptor()
This method returns the serial device file descriptor
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InputStream |
getInputStream()
This method returns the input data stream for the serial port's receive buffer
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OutputStream |
getOutputStream()
This method returns the output data stream for the serial port's transmit buffer
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boolean |
getRI()
Get the RI (ring-indicator) pin state.
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boolean |
getRTS()
Get the RTS (request-to-send) pin state.
|
boolean |
isBufferingDataReceived()
This method returns the buffering state for data received from the serial device/port.
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boolean |
isClosed()
This method is called to determine if the serial port is already closed.
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boolean |
isOpen()
This method is called to determine if the serial port is already open.
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void |
open(SerialConfig serialConfig)
This opens and initializes the serial port/device and sets the communication parameters.
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void |
open(String device,
Baud baud,
DataBits dataBits,
Parity parity,
StopBits stopBits,
FlowControl flowControl)
This opens and initializes the serial port/device and sets the communication parameters.
|
void |
open(String device,
int baud)
This opens and initializes the serial port/device and sets the communication parameters.
|
void |
open(String device,
int baud,
int dataBits,
int parity,
int stopBits,
int flowControl)
This opens and initializes the serial port/device and sets the communication parameters.
|
void |
removeListener(SerialDataEventListener... listener)
Java consumer code can call this method to unregister itself as a listener for serial data
events.
|
void |
sendBreak()
Send a BREAK signal to connected device for at least 0.25 seconds, and not more than 0.5 seconds
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void |
sendBreak(int duration)
Send a BREAK signal to connected device.
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void |
setBreak(boolean enabled)
Send a constant BREAK signal to connected device.
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void |
setBufferingDataReceived(boolean enabled)
This method controls the buffering state for data received from the serial device/port.
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void |
setDTR(boolean enabled)
Control the DTR (data-terminal-ready) pin state.
|
void |
setRTS(boolean enabled)
Control the RTS (request-to-send) pin state.
|
static final String DEFAULT_COM_PORT
open(String, int)
,
Constant Field Valuesstatic final String FIRST_USB_COM_PORT
static final String SECOND_USB_COM_PORT
void open(String device, int baud, int dataBits, int parity, int stopBits, int flowControl) throws IOException
This opens and initializes the serial port/device and sets the communication parameters. It sets the port into raw mode (character at a time and no translations).
(ATTENTION: the 'device' argument can only be a maximum of 128 characters.)
device
- The device address of the serial port to access. You can use constant
'DEFAULT_COM_PORT' if you wish to access the default serial port provided via the
GPIO header.baud
- The baud rate to use with the serial port. (Custom baud rate are not supported)dataBits
- The data bits to use for serial communication. (5,6,7,8)parity
- The parity setting to use for serial communication. (None, Event, Odd, Mark, Space)stopBits
- The stop bits to use for serial communication. (1,2)flowControl
- The flow control option to use for serial communication. (none, hardware, software)IOException
- thrown on any error.DEFAULT_COM_PORT
void open(String device, int baud) throws IOException
This opens and initializes the serial port/device and sets the communication parameters. It sets the port into raw mode (character at a time and no translations). This method will use the following default serial configuration parameters: - DATA BITS = 8 - PARITY = NONE - STOP BITS = 1 - FLOW CONTROL = NONE
(ATTENTION: the 'device' argument can only be a maximum of 128 characters.)
device
- The device address of the serial port to access. You can use constant
'DEFAULT_COM_PORT' if you wish to access the default serial port provided via the
GPIO header.baud
- The baud rate to use with the serial port.IOException
- thrown on any error.DEFAULT_COM_PORT
void open(String device, Baud baud, DataBits dataBits, Parity parity, StopBits stopBits, FlowControl flowControl) throws IOException
This opens and initializes the serial port/device and sets the communication parameters. It sets the port into raw mode (character at a time and no translations).
(ATTENTION: the 'device' argument can only be a maximum of 128 characters.)
device
- The device address of the serial port to access. You can use constant
'DEFAULT_COM_PORT' if you wish to access the default serial port provided via the
GPIO header.baud
- The baud rate to use with the serial port.dataBits
- The data bits to use for serial communication. (5,6,7,8)parity
- The parity setting to use for serial communication. (None, Event, Odd, Mark, Space)stopBits
- The stop bits to use for serial communication. (1,2)flowControl
- The flow control option to use for serial communication. (none, hardware, software)IOException
- thrown on any error.DEFAULT_COM_PORT
void open(SerialConfig serialConfig) throws IOException
This opens and initializes the serial port/device and sets the communication parameters. It sets the port into raw mode (character at a time and no translations).
(ATTENTION: the 'device' argument can only be a maximum of 128 characters.)
serialConfig
- A serial configuration object that contains the device, baud rate, data bits, parity,
stop bits, and flow control settings.IOException
- thrown on any error.DEFAULT_COM_PORT
void close() throws IllegalStateException, IOException
close
in interface AutoCloseable
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.boolean isOpen()
open(String, int)
boolean isClosed()
open(String, int)
void flush() throws IllegalStateException, IOException
Forces the transmission of any remaining data in the serial port transmit buffer. Please note that this does not force the transmission of data, it discards it!
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void discardInput() throws IllegalStateException, IOException
Discards any data in the serial receive (input) buffer. Please note that this does not force the transmission of data, it discards it!
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void discardOutput() throws IllegalStateException, IOException
Discards any data in the serial transmit (output) buffer. Please note that this does not force the transmission of data, it discards it!
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void discardAll() throws IllegalStateException, IOException
Discards any data in both the serial receive and transmit buffers. Please note that this does not force the transmission of data, it discards it!
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void sendBreak(int duration) throws IllegalStateException, IOException
Send a BREAK signal to connected device.
duration
- The length of time (milliseconds) to send the BREAK signalIllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void sendBreak() throws IllegalStateException, IOException
Send a BREAK signal to connected device for at least 0.25 seconds, and not more than 0.5 seconds
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void setBreak(boolean enabled) throws IllegalStateException, IOException
Send a constant BREAK signal to connected device. (Turn break on/off) When enabled this will send a steady stream of zero bits. When enabled, no (other) data transmitting is possible.
enabled
- The enable or disable state to control the BREAK signalIllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void setRTS(boolean enabled) throws IllegalStateException, IOException
Control the RTS (request-to-send) pin state. When enabled this will set the RTS pin to the HIGH state.
enabled
- The enable or disable state to control the RTS pin state.IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void setDTR(boolean enabled) throws IllegalStateException, IOException
Control the DTR (data-terminal-ready) pin state. When enabled this will set the DTR pin to the HIGH state.
enabled
- The enable or disable state to control the RTS pin state.IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.boolean getRTS() throws IllegalStateException, IOException
Get the RTS (request-to-send) pin state.
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.boolean getDTR() throws IllegalStateException, IOException
Get the DTR (data-terminal-ready) pin state.
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.boolean getCTS() throws IllegalStateException, IOException
Get the CTS (clean-to-send) pin state.
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.boolean getDSR() throws IllegalStateException, IOException
Get the DSR (data-set-ready) pin state.
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.boolean getRI() throws IllegalStateException, IOException
Get the RI (ring-indicator) pin state.
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.boolean getCD() throws IllegalStateException, IOException
Get the CD (carrier-detect) pin state.
IllegalStateException
- thrown if the serial port is not already open.IOException
- thrown on any error.void addListener(SerialDataEventListener... listener)
Java consumer code can call this method to register itself as a listener for serial data events.
listener
- A class instance that implements the SerialListener interface.SerialDataEventListener
,
SerialDataEvent
void removeListener(SerialDataEventListener... listener)
Java consumer code can call this method to unregister itself as a listener for serial data events.
listener
- A class instance that implements the SerialListener interface.SerialDataEventListener
,
SerialDataEvent
int getFileDescriptor()
InputStream getInputStream()
OutputStream getOutputStream()
boolean isBufferingDataReceived()
void setBufferingDataReceived(boolean enabled)
This method controls the buffering state for data received from the serial device/port.
If the buffering state is enabled, then all data bytes received from the serial port will get copied into a data receive buffer. You can use the 'getInputStream()' or and of the 'read()' methods to access this data. The data will also be available via the 'SerialDataEvent' event. It is important to know that if you are using data buffering, the data will continue to grow in memory until your program consume it from the data reader/stream.
If the buffering state is disabled, then all data bytes received from the serial port will NOT get copied into the data receive buffer, but will be included in the 'SerialDataEvent' event's data payload. If you program does not care about or use data received from the serial port, then you should disable the data buffering state to prevent memory waste/leak.
enabled
- Sets the buffering behavior state.Copyright © 2012–2019 Pi4J. All rights reserved.