c4e.phidget

Class HardwareInterface

java.lang.Object

c4e.phidget.HardwareInterface

All Implemented Interfaces:

java.lang.Runnable

public class HardwareInterface
extends java.lang.Object
implements java.lang.Runnable

This class encapsulates a number of hardware devices and simplifies interfacing with them. It exposes the hardware state through events while hiding exception and synchronization details. It also provides a timer callback.

Since:

Fall 2014

Version:

0.3

Author:

Michael Jenkin and Hamzeh Roumani

Constructor Summary

Constructors

Constructor and Description
HardwareInterface() Construct a hardware interface with no debugging messages.
HardwareInterface(boolean debug) Construct a hardware interface with the indicated debugging flag.

Method Summary

Modifier and Type	Method and Description
void	analogInputChanged(Event event) Callback for a change event in one of the analog inputs.
void	digitalInputChanged(Event event) Callback for a change event in one of the digital inputs.
void	digitalOutputChanged(Event event) Callback for a change event in one of the digital outputs.
InterfaceKitPhidget	getInterfaceBoard() Capture the interface board if present.
boolean	getOutputState(int id) Determine the state of a digital output.
RFIDPhidget	getRFIDBoard() Capture the RFID board if present.
double	getServoAcceleration(int index) Determine the acceleration of a given servo motor.
double	getServoAccelerationMax(int index) Determine the maximum acceleration that a servo will accept.
double	getServoAccelerationMin(int index) Determine the minimum acceleration that a servo will accept.
AdvancedServoPhidget	getServoBoard() Capture the servo motor board if present.
double	getServoCurrent(int index) Determine the current usage of a given servo motor in Amps.
double	getServoPosition(int index) Set the position of a servo motor.
double	getServoPositionMax(int index) Determine the maximum position that a servo will accept.
double	getServoPositionMin(int index) Determine the minimum position that a servo will accept.
double	getServoVelocity(int index) Determine the velocity of a given servo motor in Amps.
void	rfidOutputChanged(Event event) Callback for a change event in the RFID output.
void	run() The timer thread.
void	servoCurrentChanged(Event event) Callback for a change event in a servo current.
void	servoPositionChanged(Event event) Callback for a change event in a servo position.
void	servoVelocityChanged(Event event) Callback for a change event in a servo velocity.
void	setAntennaOn(boolean state) Set the state of the antenna of the RFID board.
void	setLED(boolean state) Set the state of the LED on the RFID board.
void	setOutputState(int id, boolean value) Set the state of a digital output.
void	setServoAcceleration(int index, double acceleration) Set the acceleration of a servo motor.
void	setServoEngageState(int index, boolean state) Engage or disengage a servo motor.
void	setServoPosition(int index, double position) Set the position of a servo motor.
void	setTimer(long delay) Set the timer to fire an event, thereby calling timerCallback(), after the indicated delay.
void	startMonitoring() Start listening to the attached hardware and trigger corresponding events.
void	stopMonitoring() Stop listening to the attached hardware.
void	tagGained(Event event) Callback for an RFID tag gain event.
void	tagLost(Event event) Callback for an RFID tag loss event.
void	timerCallback() Callback for the timer event.

Methods inherited from class java.lang.Object

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

Constructor Detail

HardwareInterface

public HardwareInterface()

Construct a hardware interface with no debugging messages.

HardwareInterface

public HardwareInterface(boolean debug)

Construct a hardware interface with the indicated debugging flag.

Parameters:

debug - turn debugging messages on (true) or off (false)

Method Detail

setOutputState

public final void setOutputState(int id,
                                 boolean value)

Set the state of a digital output.

Parameters:

id - the index number of the digit output to set.

value - true to activate the output, false otherwise.

getOutputState

public final boolean getOutputState(int id)

Determine the state of a digital output.

Parameters:

id - the index number of the digit output to get.

value - true to activate the output, false otherwise.

setAntennaOn

public final void setAntennaOn(boolean state)

Set the state of the antenna of the RFID board. The antenna is deactivated by default so it needs to be explicitly activated before tags can be read. Control over the antenna allows multiple readers to be used in close proximity, as multiple readers will interfere with each other if their antennas are activated simultaneously.

Parameters:

state - true to activate the antenna, false otherwise.

setLED

public final void setLED(boolean state)

Set the state of the LED on the RFID board. The LED is off by default.

Parameters:

state - true to turn the LED on, false otherwise.

setServoPosition

public final void setServoPosition(int index,
                                   double position)

Set the position of a servo motor. The position corresponds to an angle in degrees.

Parameters:

index - the motor index.

position - the desired position in the range allowed by the motor, see getServoPositionMin(int) and getServoPositionMax(int).

getServoPosition

public final double getServoPosition(int index)

Set the position of a servo motor. The position corresponds to an angle in degrees.

Parameters:

index - the motor index.

Returns:

the current position of the indicated motor.

getServoPositionMin

public final double getServoPositionMin(int index)

Determine the minimum position that a servo will accept.

Parameters:

index - the motor index.

Returns:

the minimum position or NaN if no such motor is attached.

getServoPositionMax

public final double getServoPositionMax(int index)

Determine the maximum position that a servo will accept.

Parameters:

index - the motor index.

Returns:

the maximum position or NaN if no such motor is attached.

setServoAcceleration

public final void setServoAcceleration(int index,
                                       double acceleration)

Set the acceleration of a servo motor. This controls how fast the motor changes speed.

Parameters:

index - the motor index.

acceleration - the desired acceleration in the range allowed by the motor, see getServoAccelerationMin(int) and getServoAccelerationMax(int).

getServoAccelerationMin

public final double getServoAccelerationMin(int index)

Determine the minimum acceleration that a servo will accept.

Parameters:

index - the motor index.

Returns:

the minimum acceleration or NaN if no such motor is attached.

getServoAccelerationMax

public final double getServoAccelerationMax(int index)

Determine the maximum acceleration that a servo will accept.

Parameters:

index - the motor index.

Returns:

the maximum acceleration or NaN if no such motor is attached.

getServoAcceleration

public final double getServoAcceleration(int index)

Determine the acceleration of a given servo motor.

Parameters:

index - the motor index.

Returns:

the acceleration or NaN if no such motor is attached.

getServoCurrent

public final double getServoCurrent(int index)

Determine the current usage of a given servo motor in Amps.

Parameters:

index - the motor index.

Returns:

the current or NaN if no such motor is attached.

getServoVelocity

public final double getServoVelocity(int index)

Determine the velocity of a given servo motor in Amps.

Parameters:

index - the motor index.

Returns:

the velocity or NaN if no such motor is attached.

setServoEngageState

public final void setServoEngageState(int index,
                                      boolean state)

Engage or disengage a servo motor. The motor is disengaged by default but it gets engaged automatically when you set its position (via setServoPosition(int, double)). Hence, this method is intended for changing the engage state without changing the position.

Parameters:

index - the motor index.

state - true to engage, false to disengage.

digitalOutputChanged

public void digitalOutputChanged(Event event)

Callback for a change event in one of the digital outputs.

Parameters:

event - the event that occurred

analogInputChanged

public void analogInputChanged(Event event)

Callback for a change event in one of the analog inputs.

Parameters:

event - the event that occurred

digitalInputChanged

public void digitalInputChanged(Event event)

Callback for a change event in one of the digital inputs.

Parameters:

event - the event that occurred

servoPositionChanged

public void servoPositionChanged(Event event)

Callback for a change event in a servo position.

Parameters:

event - the event that occurred

servoVelocityChanged

public void servoVelocityChanged(Event event)

Callback for a change event in a servo velocity.

Parameters:

event - the event that occurred

servoCurrentChanged

public void servoCurrentChanged(Event event)

Callback for a change event in a servo current.

Parameters:

event - the event that occurred

tagGained

public void tagGained(Event event)

Callback for an RFID tag gain event.

Parameters:

event - the event that occurred

tagLost

public void tagLost(Event event)

Callback for an RFID tag loss event.

Parameters:

event - the event that occurred

rfidOutputChanged

public void rfidOutputChanged(Event event)

Callback for a change event in the RFID output.

Parameters:

event - the event that occurred

timerCallback

public void timerCallback()

Callback for the timer event.

getInterfaceBoard

public final InterfaceKitPhidget getInterfaceBoard()

Capture the interface board if present.

Returns:

the board object if present, null otherwise.

getServoBoard

public final AdvancedServoPhidget getServoBoard()

Capture the servo motor board if present.

Returns:

the board object if present, null otherwise.

getRFIDBoard

public final RFIDPhidget getRFIDBoard()

Capture the RFID board if present.

Returns:

the board object if present, null otherwise.

setTimer

public final void setTimer(long delay)

Set the timer to fire an event, thereby calling timerCallback(), after the indicated delay. The event will be fired only once, so if periodic firing is needed then call this method in the callback handler. Note that if this method is re-invoked before the indicated delay passes then the previous invocation is cancelled.

Parameters:

delay - the number of milliseconds between now and the firing of the timer event.

Throws:

java.lang.RuntimeException - if the delay is not positive.

run

public final void run()

The timer thread.

Specified by:

run in interface java.lang.Runnable

startMonitoring

public final void startMonitoring()

Start listening to the attached hardware and trigger corresponding events. This method should be called once by the client application in order to initiate the listening process. This method does not return, thus hanging its thread until the stopMonitoring() method is called.

stopMonitoring

public final void stopMonitoring()

Stop listening to the attached hardware. This method should be called once at the end of the client application in order to terminate the listening thread.