org.lsst.ccs.drivers.gpio

Class GPIODriver

java.lang.Object

org.lsst.ccs.drivers.gpio.GPIODriver

public class GPIODriver
extends Object

A general purpose GPIO driver. This driver has been tested on UNO 1483 and raspberry pi 3, but should work on other Linux systems with minimal changes.

Author:

tonyj

See Also:

Linux GPIO documentation

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GPIODriver.GPIOChannel A class representing a single GPIO Channel
class	GPIODriver.GPIOChip A class representing a GPIOChip

Constructor Summary

Constructors

Constructor and Description
GPIODriver() Create an instance of GPIO driver

Method Summary

Modifier and Type	Method and Description
List<GPIODriver.GPIOChip>	enumerateChips() Enumerate the GPIO chips on this machine
List<GPIODriver.GPIOChannel>	enumerateExportedChannels() Enumerate the currently exported GPIO channels on this machine
GPIODriver.GPIOChannel	export(int channel) Export the specified channel.
List<GPIODriver.GPIOChannel>	exportRange(int base, int ngpio) Export all of the channels in the given range.
GPIODriver.GPIOChannel	getChannel(int channel) Get a specified GPIO channel
boolean	isExported(int channel) Test if the given channel is already exported
void	unexport(int channel) Unexport the specified channel
void	unexportRange(int base, int ngpio) Unexport all of the channels in the given range.

Methods inherited from class java.lang.Object

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

Constructor Detail

GPIODriver

public GPIODriver()
           throws org.lsst.ccs.drivers.commons.DriverException

Create an instance of GPIO driver

Throws:

org.lsst.ccs.drivers.commons.DriverException - If the system does not support GPIO

Method Detail

enumerateChips

public List<GPIODriver.GPIOChip> enumerateChips()
                                         throws org.lsst.ccs.drivers.commons.DriverException

Enumerate the GPIO chips on this machine

Returns:

The list of GPIO chips

Throws:

org.lsst.ccs.drivers.commons.DriverException - If an IO error occurs while enumerating the chips

enumerateExportedChannels

public List<GPIODriver.GPIOChannel> enumerateExportedChannels()
                                                       throws org.lsst.ccs.drivers.commons.DriverException

Enumerate the currently exported GPIO channels on this machine

Returns:

The list of exported channels

Throws:

org.lsst.ccs.drivers.commons.DriverException - If an IO exception occurs during the enumeration

getChannel

public GPIODriver.GPIOChannel getChannel(int channel)
                                  throws org.lsst.ccs.drivers.commons.DriverException

Get a specified GPIO channel

Parameters:

channel - The channel to fetch

Returns:

The Channel

Throws:

org.lsst.ccs.drivers.commons.DriverException - If the GPIO can not be fetched, for example if it has not been exported.

isExported

public boolean isExported(int channel)

Test if the given channel is already exported

Parameters:

channel - The channel to test

Returns:

true if and only if the channel has already been exported.

export

public GPIODriver.GPIOChannel export(int channel)
                              throws org.lsst.ccs.drivers.commons.DriverException

Export the specified channel.

Parameters:

channel - The channel number

Returns:

The exported channel

Throws:

org.lsst.ccs.drivers.commons.DriverException - If the channel is invalid, or cannot be exported

exportRange

public List<GPIODriver.GPIOChannel> exportRange(int base,
                                                int ngpio)
                                         throws org.lsst.ccs.drivers.commons.DriverException

Export all of the channels in the given range. Channels which are already exported are not re-exported.

Parameters:

base - The first channel to export

ngpio - The number of channels to export

Returns:

The list of exported channels. including any which were already exported.

Throws:

org.lsst.ccs.drivers.commons.DriverException - If an error occurs.

unexportRange

public void unexportRange(int base,
                          int ngpio)
                   throws org.lsst.ccs.drivers.commons.DriverException

Unexport all of the channels in the given range. Channels which are not already exported are ignored.

Parameters:

base - The first channel to unexport

ngpio - The number of channels to unexport

Throws:

org.lsst.ccs.drivers.commons.DriverException - If an error occurs.

unexport

public void unexport(int channel)
              throws org.lsst.ccs.drivers.commons.DriverException

Unexport the specified channel

Parameters:

channel - The channel number

Throws:

org.lsst.ccs.drivers.commons.DriverException - If the channel is invalid, or cannot be un exported