edu.wpi.first.wpilibj

Class SerialPort

java.lang.Object

edu.wpi.first.wpilibj.SerialPort

public class SerialPort
extends java.lang.Object

Driver for the RS-232 serial port on the roboRIO.

The current implementation uses the VISA formatted I/O mode. This means that all traffic goes through the formatted buffers. This allows the intermingled use of print(), readString(), and the raw buffer accessors read() and write().

More information can be found in the NI-VISA User Manual here: http://www.ni .com/pdf/manuals/370423a.pdf and the NI-VISA Programmer's Reference Manual here: http://www.ni.com/pdf/manuals/370132c.pdf

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SerialPort.FlowControl Represents what type of flow control to use for serial communication.
static class	SerialPort.Parity Represents the parity to use for serial communications.
static class	SerialPort.Port
static class	SerialPort.StopBits Represents the number of stop bits to use for Serial Communication.
static class	SerialPort.WriteBufferMode Represents which type of buffer mode to use when writing to a serial m_port.

Constructor Summary

Constructors

Constructor and Description
SerialPort(int baudRate, SerialPort.Port port) Create an instance of a Serial Port class.
SerialPort(int baudRate, SerialPort.Port port, int dataBits) Create an instance of a Serial Port class.
SerialPort(int baudRate, SerialPort.Port port, int dataBits, SerialPort.Parity parity) Create an instance of a Serial Port class.
SerialPort(int baudRate, SerialPort.Port port, int dataBits, SerialPort.Parity parity, SerialPort.StopBits stopBits) Create an instance of a Serial Port class.

Method Summary

Modifier and Type	Method and Description
void	disableTermination() Disable termination behavior.
void	enableTermination() Enable termination with the default terminator '\n'
void	enableTermination(char terminator) Enable termination and specify the termination character.
void	flush() Force the output buffer to be written to the port.
void	free() Destructor.
int	getBytesReceived() Get the number of bytes currently available to read from the serial port.
byte[]	read(int count) Read raw bytes out of the buffer.
java.lang.String	readString() Read a string out of the buffer.
java.lang.String	readString(int count) Read a string out of the buffer.
void	reset() Reset the serial port driver to a known state.
void	setFlowControl(SerialPort.FlowControl flowControl) Set the type of flow control to enable on this port.
void	setReadBufferSize(int size) Specify the size of the input buffer.
void	setTimeout(double timeout) Configure the timeout of the serial m_port.
void	setWriteBufferMode(SerialPort.WriteBufferMode mode) Specify the flushing behavior of the output buffer.
void	setWriteBufferSize(int size) Specify the size of the output buffer.
int	write(byte[] buffer, int count) Write raw bytes to the serial port.
int	writeString(java.lang.String data) Write a string to the serial port

Methods inherited from class java.lang.Object

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

Constructor Detail

SerialPort

public SerialPort(int baudRate,
                  SerialPort.Port port,
                  int dataBits,
                  SerialPort.Parity parity,
                  SerialPort.StopBits stopBits)

Create an instance of a Serial Port class.

Parameters:

baudRate - The baud rate to configure the serial port.

port - The Serial port to use

dataBits - The number of data bits per transfer. Valid values are between 5 and 8 bits.

parity - Select the type of parity checking to use.

stopBits - The number of stop bits to use as defined by the enum StopBits.

SerialPort

public SerialPort(int baudRate,
                  SerialPort.Port port,
                  int dataBits,
                  SerialPort.Parity parity)

Create an instance of a Serial Port class. Defaults to one stop bit.

Parameters:

baudRate - The baud rate to configure the serial port.

dataBits - The number of data bits per transfer. Valid values are between 5 and 8 bits.

parity - Select the type of parity checking to use.

SerialPort

public SerialPort(int baudRate,
                  SerialPort.Port port,
                  int dataBits)

Create an instance of a Serial Port class. Defaults to no parity and one stop bit.

Parameters:

baudRate - The baud rate to configure the serial port.

dataBits - The number of data bits per transfer. Valid values are between 5 and 8 bits.

SerialPort

public SerialPort(int baudRate,
                  SerialPort.Port port)

Create an instance of a Serial Port class. Defaults to 8 databits, no parity, and one stop bit.

Parameters:

baudRate - The baud rate to configure the serial port.

Method Detail

free

public void free()

Destructor.

setFlowControl

public void setFlowControl(SerialPort.FlowControl flowControl)

Set the type of flow control to enable on this port.

By default, flow control is disabled.

Parameters:

flowControl - the FlowControl m_value to use

enableTermination

public void enableTermination(char terminator)

Enable termination and specify the termination character.

Termination is currently only implemented for receive. When the the terminator is received, the read() or readString() will return fewer bytes than requested, stopping after the terminator.

Parameters:

terminator - The character to use for termination.

enableTermination

public void enableTermination()

Enable termination with the default terminator '\n'

Termination is currently only implemented for receive. When the the terminator is received, the read() or readString() will return fewer bytes than requested, stopping after the terminator.

The default terminator is '\n'

disableTermination

public void disableTermination()

Disable termination behavior.

getBytesReceived

public int getBytesReceived()

Get the number of bytes currently available to read from the serial port.

Returns:

The number of bytes available to read.

readString

public java.lang.String readString()

Read a string out of the buffer. Reads the entire contents of the buffer

Returns:

The read string

readString

public java.lang.String readString(int count)

Read a string out of the buffer. Reads the entire contents of the buffer

Parameters:

count - the number of characters to read into the string

Returns:

The read string

read

public byte[] read(int count)

Read raw bytes out of the buffer.

Parameters:

count - The maximum number of bytes to read.

Returns:

An array of the read bytes

write

public int write(byte[] buffer,
                 int count)

Write raw bytes to the serial port.

Parameters:

buffer - The buffer of bytes to write.

count - The maximum number of bytes to write.

Returns:

The number of bytes actually written into the port.

writeString

public int writeString(java.lang.String data)

Write a string to the serial port

Parameters:

data - The string to write to the serial port.

Returns:

The number of bytes actually written into the port.

setTimeout

public void setTimeout(double timeout)

Configure the timeout of the serial m_port.

This defines the timeout for transactions with the hardware. It will affect reads if less bytes are available than the read buffer size (defaults to 1) and very large writes.

Parameters:

timeout - The number of seconds to to wait for I/O.

setReadBufferSize

public void setReadBufferSize(int size)

Specify the size of the input buffer.

Specify the amount of data that can be stored before data from the device is returned to Read. If you want data that is received to be returned immediately, set this to 1.

It the buffer is not filled before the read timeout expires, all data that has been received so far will be returned.

Parameters:

size - The read buffer size.

setWriteBufferSize

public void setWriteBufferSize(int size)

Specify the size of the output buffer.

Specify the amount of data that can be stored before being transmitted to the device.

Parameters:

size - The write buffer size.

setWriteBufferMode

public void setWriteBufferMode(SerialPort.WriteBufferMode mode)

Specify the flushing behavior of the output buffer.

When set to kFlushOnAccess, data is synchronously written to the serial port after each call to either print() or write().

When set to kFlushWhenFull, data will only be written to the serial port when the buffer is full or when flush() is called.

Parameters:

mode - The write buffer mode.

flush

public void flush()

Force the output buffer to be written to the port.

This is used when setWriteBufferMode() is set to kFlushWhenFull to force a flush before the buffer is full.

reset

public void reset()

Reset the serial port driver to a known state.

Empty the transmit and receive buffers in the device and formatted I/O.