UartDevice
public
class
UartDevice
extends Object
implements
Closeable
| java.lang.Object | |
| ↳ | com.google.android.things.pio.UartDevice |
Controls an UART device.
Opening an UART device takes ownership of it for the whole system, preventing anyone else from
opening/accessing this device until you call close(). Forgetting to call close()
will prevent anyone (including the same process/app) from using the device.
Summary
Constants | |
|---|---|
int |
FLUSH_IN
|
int |
FLUSH_IN_OUT
|
int |
FLUSH_OUT
|
int |
HW_FLOW_CONTROL_AUTO_RTSCTS
|
int |
HW_FLOW_CONTROL_NONE
|
int |
MODEM_CONTROL_CD
|
int |
MODEM_CONTROL_CTS
|
int |
MODEM_CONTROL_DSR
|
int |
MODEM_CONTROL_DTR
|
int |
MODEM_CONTROL_LE
|
int |
MODEM_CONTROL_RI
|
int |
MODEM_CONTROL_RTS
|
int |
MODEM_CONTROL_SR
|
int |
MODEM_CONTROL_ST
|
int |
PARITY_EVEN
|
int |
PARITY_MARK
|
int |
PARITY_NONE
|
int |
PARITY_ODD
|
int |
PARITY_SPACE
|
Public methods | |
|---|---|
void
|
clearModemControl(int lines)
Clear selected modem control lines. |
void
|
close()
Close and release the device. |
void
|
flush(int direction)
Flush the specified queue for the device. |
int
|
read(byte[] buffer, int length)
Read data from the device. |
void
|
registerUartDeviceCallback(UartDeviceCallback callback, Handler handler)
Registers a callback for interrupts. |
final
void
|
registerUartDeviceCallback(UartDeviceCallback callback)
Registers a callback for interrupts. |
void
|
sendBreak(int duration_msecs)
Send a break to the device. |
void
|
setBaudrate(int rate)
Set the device baud rate. |
void
|
setDataSize(int size)
Set the device data size. |
void
|
setHardwareFlowControl(int mode)
Set the hardware flow control mode. |
void
|
setModemControl(int lines)
Set selected modem control lines. |
void
|
setParity(int mode)
Set the device parity mode. |
void
|
setStopBits(int bits)
Set the device stop bits. |
void
|
unregisterUartDeviceCallback(UartDeviceCallback callback)
Unregisters a callback. |
int
|
write(byte[] buffer, int length)
Write data to the device. |
Inherited methods | |
|---|---|
 From
class
java.lang.Object
| |
From
interface
java.io.Closeable
| |
From
interface
java.lang.AutoCloseable
| |
Constants
FLUSH_IN
int FLUSH_IN
Queue constant used to flush UART data that has been received but not
read.
Constant Value: 0 (0x00000000)
FLUSH_IN_OUT
int FLUSH_IN_OUT
Queue constant used to flush UART data that has both been received and
written.
Constant Value: 2 (0x00000002)
FLUSH_OUT
int FLUSH_OUT
Queue constant used to flush UART data that has been written but not
transmitted.
Constant Value: 1 (0x00000001)
HW_FLOW_CONTROL_AUTO_RTSCTS
int HW_FLOW_CONTROL_AUTO_RTSCTS
Mode constant used to configure a UART device to use
automatic RTS/CTS hardware flow control.
Constant Value: 1 (0x00000001)
HW_FLOW_CONTROL_NONE
int HW_FLOW_CONTROL_NONE
Mode constant used to configure a UART device to use no
hardware flow control.
Constant Value: 0 (0x00000000)
MODEM_CONTROL_CD
int MODEM_CONTROL_CD
Bit constant used to configure a UART device
data carrier detect.
Constant Value: 64 (0x00000040)
MODEM_CONTROL_CTS
int MODEM_CONTROL_CTS
Bit constant used to configure a UART device
clear to send.
Constant Value: 32 (0x00000020)
MODEM_CONTROL_DSR
int MODEM_CONTROL_DSR
Bit constant used to configure a UART device
data set ready.
Constant Value: 256 (0x00000100)
MODEM_CONTROL_DTR
int MODEM_CONTROL_DTR
Bit constant used to configure a UART device
data terminal ready.
Constant Value: 2 (0x00000002)
MODEM_CONTROL_LE
int MODEM_CONTROL_LE
Bit constant used to configure a UART device
data set ready/Line enable.
Constant Value: 1 (0x00000001)
MODEM_CONTROL_RI
int MODEM_CONTROL_RI
Bit constant used to configure a UART device
ring.
Constant Value: 128 (0x00000080)
MODEM_CONTROL_RTS
int MODEM_CONTROL_RTS
Bit constant used to configure a UART device
request to send.
Constant Value: 4 (0x00000004)
MODEM_CONTROL_SR
int MODEM_CONTROL_SR
Bit constant used to configure a UART device
secondary RXD.
Constant Value: 16 (0x00000010)
MODEM_CONTROL_ST
int MODEM_CONTROL_ST
Bit constant used to configure a UART device
secondary TXD.
Constant Value: 8 (0x00000008)
PARITY_EVEN
int PARITY_EVEN
Mode constant used to configure a UART device to use even parity.
Constant Value: 1 (0x00000001)
PARITY_MARK
int PARITY_MARK
Mode constant used to configure a UART device to use mark parity.
Constant Value: 3 (0x00000003)
PARITY_NONE
int PARITY_NONE
Mode constant used to configure a UART device to use no parity.
Constant Value: 0 (0x00000000)
PARITY_ODD
int PARITY_ODD
Mode constant used to configure a UART device to use odd parity.
Constant Value: 2 (0x00000002)
PARITY_SPACE
int PARITY_SPACE
Mode constant used to configure a UART device to use space parity.
Constant Value: 4 (0x00000004)
Public methods
clearModemControl
</div>
void clearModemControl (int lines)
Clear selected modem control lines.
| Parameters | |
|---|---|
lines |
int:
The set of lines to clear. Available lines are MODEM_CONTROL_LE,
MODEM_CONTROL_DTR, MODEM_CONTROL_RTS, MODEM_CONTROL_ST, MODEM_CONTROL_SR, MODEM_CONTROL_CTS, MODEM_CONTROL_CD, MODEM_CONTROL_RI, MODEM_CONTROL_DSR. |
| Throws | |
|---|---|
IOException |
|
</div>
close
</div>
void close ()
Close and release the device.
Must be called in order to make the device available to other users.</p>
| Throws | |
|---|---|
IOException |
if the UartDevice is already closed. |
</div>
flush
</div>
void flush (int direction)
Flush the specified queue for the device.
| Parameters | |
|---|---|
direction |
int:
Queue to flush. One of FLUSH_IN, FLUSH_OUT, FLUSH_IN_OUT. |
| Throws | |
|---|---|
IOException |
|
</div>
read
</div>
int read (byte[] buffer,
int length)
Read data from the device.
This call is non-blocking and may read fewer than bytes than requested. If no data is ready, this will return 0.</p>
| Parameters | |
|---|---|
buffer |
byte:
Buffer to read into. |
length |
int:
Number of bytes to read, may not be larger than the buffer size. |
| Returns | |
|---|---|
int |
The number of bytes read. |
| Throws | |
|---|---|
|
IOException |
|
IllegalArgumentException |
IOException |
|
See also:
write(byte[], int)
</div>
registerUartDeviceCallback
</div>
void registerUartDeviceCallback (UartDeviceCallback callback, Handler handler)
Registers a callback for interrupts.
The callback will be called when data is ready to read.</p>
| Parameters | |
|---|---|
callback |
UartDeviceCallback:
UartDeviceCallback to register. |
handler |
Handler:
The Handler to run callbacks on, or null to use the current thread. |
| Throws | |
|---|---|
|
IOException |
IOException |
|
See also:
registerUartDeviceCallback(UartDeviceCallback)unregisterUartDeviceCallback(UartDeviceCallback)
</div>
registerUartDeviceCallback
</div>
void registerUartDeviceCallback (UartDeviceCallback callback)
Registers a callback for interrupts.
Equivalent to registerUartDeviceCallback(callback, null).</p>
| Parameters | |
|---|---|
callback |
UartDeviceCallback:
UartDeviceCallback to register. |
| Throws | |
|---|---|
|
IOException |
IOException |
|
See also:
registerUartDeviceCallback(UartDeviceCallback, Handler)unregisterUartDeviceCallback(UartDeviceCallback)
</div>
sendBreak
</div>
void sendBreak (int duration_msecs)
Send a break to the device.
| Parameters | |
|---|---|
duration_msecs |
int:
Duration of break in milliseconds. |
| Throws | |
|---|---|
IOException |
|
</div>
setBaudrate
</div>
void setBaudrate (int rate)
Set the device baud rate.
| Parameters | |
|---|---|
rate |
int:
Rate in baud per seconds. |
| Throws | |
|---|---|
IOException |
if the requested baudrate is unsupported by the hardware. |
IllegalArgumentException |
if the requested baudrate is negative or zero. |
</div>
setDataSize
</div>
void setDataSize (int size)
Set the device data size.
| Parameters | |
|---|---|
size |
int:
Data size in bits. |
| Throws | |
|---|---|
|
IOException |
IllegalArgumentException |
if the requested data size is negative or zero. |
IOException |
|
</div>
setHardwareFlowControl
</div>
void setHardwareFlowControl (int mode)
Set the hardware flow control mode.
| Parameters | |
|---|---|
mode |
int:
Flow control mode. One of HW_FLOW_CONTROL_NONE, HW_FLOW_CONTROL_AUTO_RTSCTS. |
| Throws | |
|---|---|
IOException |
|
</div>
setModemControl
</div>
void setModemControl (int lines)
Set selected modem control lines.
| Parameters | |
|---|---|
lines |
int:
The set of lines to enable. Available lines are MODEM_CONTROL_LE,
MODEM_CONTROL_DTR, MODEM_CONTROL_RTS, MODEM_CONTROL_ST, MODEM_CONTROL_SR, MODEM_CONTROL_CTS, MODEM_CONTROL_CD, MODEM_CONTROL_RI, MODEM_CONTROL_DSR. |
| Throws | |
|---|---|
IOException |
|
</div>
setParity
</div>
void setParity (int mode)
Set the device parity mode.
| Parameters | |
|---|---|
mode |
int:
Parity mode. One of PARITY_NONE, PARITY_EVEN, PARITY_ODD, PARITY_MARK, PARITY_SPACE. |
| Throws | |
|---|---|
IOException |
|
</div>
setStopBits
</div>
void setStopBits (int bits)
Set the device stop bits.
| Parameters | |
|---|---|
bits |
int:
Number of stop bits. |
| Throws | |
|---|---|
|
IOException |
IllegalArgumentException |
if the requested stop bits is negative. |
IOException |
|
</div>
unregisterUartDeviceCallback
</div>
void unregisterUartDeviceCallback (UartDeviceCallback callback)
Unregisters a callback.
| Parameters | |
|---|---|
callback |
UartDeviceCallback:
PioInterruptCallback to unregister. |
See also:
registerUartDeviceCallback(UartDeviceCallback, Handler)
</div>
write
</div>
int write (byte[] buffer,
int length)
Write data to the device.
This call is non-blocking and may write fewer bytes than requested. If no data can be written, this will return 0.</p>
| Parameters | |
|---|---|
buffer |
byte:
Data to write. |
length |
int:
Number of bytes to write, may not be larger than the buffer size. |
| Returns | |
|---|---|
int |
The number of bytes written. |
| Throws | |
|---|---|
|
IOException |
|
IllegalArgumentException |
IOException |
|
See also:
read(byte[], int)
</div>