Uart Class Reference

Detailed Description

This file defines the UART interface for libmraa

        Uart uart = new Uart(0);

        if (uart.setBaudRate(115200) != Result.SUCCESS) {
            System.err.println("Error setting baud rate");
            System.exit(1);
        }

        if (uart.setMode(8, UartParity.UART_PARITY_NONE, 1) != Result.SUCCESS) {
            System.err.println("Error setting mode");
            System.exit(1);
        }

        if (uart.setFlowcontrol(false, false) != Result.SUCCESS) {
            System.err.println("Error setting flow control");
            System.exit(1);
        }

        uart.writeStr("Hello monkeys");

Public Member Functions
synchronized void	delete ()
	Uart (int uart)
	Uart (String path)
String	getDevicePath ()
String	readStr (int length)
int	writeStr (String data)
boolean	dataAvailable (long millis)
boolean	dataAvailable ()
Result	flush ()
Result	sendBreak (int duration)
Result	setBaudRate (long baud)
Result	setMode (int bytesize, UartParity parity, int stopbits)
Result	setFlowcontrol (boolean xonxoff, boolean rtscts)
Result	setTimeout (int read, int write, int interchar)
Result	setNonBlocking (boolean nonblock)

Constructor & Destructor Documentation

Uart

(

int

uart

)

Uart Constructor, takes a pin number which will map directly to the linux uart number, this 'enables' the uart, nothing more

Parameters

uart	the index of the uart set to use

Uart

(

String

path

)

Uart Constructor, takes a pin number which will map directly to the linux uart number, this 'enables' the uart, nothing more

Parameters

uart	the index of the uart set to use

Member Function Documentation

boolean dataAvailable

(

long

millis

)

Check to see if data is available on the device for reading

Parameters

millis

number of milliseconds to wait, or 0 to return immediately

Returns

true if there is data available to read, false otherwise

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Result flush

(

)

Flush the outbound data. Blocks until complete.

Returns

Result of operation

String getDevicePath

(

)

Get string with tty device path within Linux For example. Could point to "/dev/ttyS0"

Returns

char pointer of device path

String readStr

(

int

length

)

Read bytes from the device into a String object

Parameters

length

to read

Exceptions

std::bad_alloc

If there is no space left for read.

Returns

string of data

Result sendBreak

(

int

duration

)

Send a break to the device. Blocks until complete.

Parameters

duration

When 0, send a break lasting at least 250 milliseconds, and not more than 500 milliseconds. When non zero, the break duration is implementation specific.

Returns

Result of operation

Result setBaudRate

(

long

baud

)

Set the baudrate. Takes an int and will attempt to decide what baudrate is to be used on the UART hardware.

Parameters

baud	unsigned int of baudrate i.e. 9600

Returns

Result of operation

Result setFlowcontrol	(	boolean	xonxoff,
		boolean	rtscts
	)

Set the flowcontrol

Parameters

xonxoff	XON/XOFF Software flow control.
rtscts	RTS/CTS out of band hardware flow control

Returns

Result of operation

Result setMode	(	int	bytesize,
		UartParity	parity,
		int	stopbits
	)

Set the transfer mode For example setting the mode to 8N1 would be "dev.setMode(8,UART_PARITY_NONE , 1)"

Parameters

bytesize	data bits
parity	Parity bit setting
stopbits	stop bits

Returns

Result of operation

Result setNonBlocking

(

boolean

nonblock

)

Set the blocking state for write operations

Parameters

nonblock

new nonblocking state

Returns

Result of operation

Result setTimeout	(	int	read,
		int	write,
		int	interchar
	)

Set the timeout for read and write operations <= 0 will disable that timeout

Parameters

read	read timeout
write	write timeout
interchar	inbetween char timeout

Returns

Result of operation

int writeStr

(

String

data

)

Write bytes in String object to a device

Parameters

data	string to write

Returns

the number of bytes written, or -1 if an error occurred

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The documentation for this class was generated from the following file:

• Uart.java