AnalogTriggerOutput Class Reference

#include <AnalogTriggerOutput.h>

Inheritance diagram for AnalogTriggerOutput:

List of all members.

Public Types
enum	Type { kInWindow = 0, kState = 1, kRisingPulse = 2, kFallingPulse = 3 }
Public Member Functions
bool	Get ()
virtual UINT32	GetChannelForRouting ()
virtual UINT32	GetModuleForRouting ()
virtual bool	GetAnalogTriggerForRouting ()
virtual void	RequestInterrupts (tInterruptHandler handler, void *param=NULL)
	Asynchronus handler version.
virtual void	RequestInterrupts ()
	Synchronus Wait version.
Protected Member Functions
	AnalogTriggerOutput (AnalogTrigger *trigger, Type outputType)
Friends
class	AnalogTrigger

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Detailed Description

Class to represent a specific output from an analog trigger. This class is used to get the current output value and also as a DigitalSource to provide routing of an output to digital subsystems on the FPGA such as Counter, Encoder, and Interrupt.

The TriggerState output indicates the primary output value of the trigger. If the analog signal is less than the lower limit, the output is false. If the analog value is greater than the upper limit, then the output is true. If the analog value is in between, then the trigger output state maintains its most recent value.

The InWindow output indicates whether or not the analog signal is inside the range defined by the limits.

The RisingPulse and FallingPulse outputs detect an instantaneous transition from above the upper limit to below the lower limit, and vise versa. These pulses represent a rollover condition of a sensor and can be routed to an up / down couter or to interrupts. Because the outputs generate a pulse, they cannot be read directly. To help ensure that a rollover condition is not missed, there is an average rejection filter available that operates on the upper 8 bits of a 12 bit number and selects the nearest outlyer of 3 samples. This will reject a sample that is (due to averaging or sampling) errantly between the two limits. This filter will fail if more than one sample in a row is errantly in between the two limits. You may see this problem if attempting to use this feature with a mechanical rollover sensor, such as a 360 degree no-stop potentiometer without signal conditioning, because the rollover transition is not sharp / clean enough. Using the averaging engine may help with this, but rotational speeds of the sensor will then be limited.

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Constructor & Destructor Documentation

AnalogTriggerOutput::AnalogTriggerOutput	(	AnalogTrigger *	trigger,
		AnalogTriggerOutput::Type	outputType
	)		[protected]

Create an object that represents one of the four outputs from an analog trigger.

Because this class derives from DigitalSource, it can be passed into routing functions for Counter, Encoder, etc.

Parameters:

trigger	A pointer to the trigger for which this is an output.
outputType	An enum that specifies the output on the trigger to represent.

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Member Function Documentation

bool AnalogTriggerOutput::Get

(

)

Get the state of the analog trigger output.

Returns:

The state of the analog trigger output.

bool AnalogTriggerOutput::GetAnalogTriggerForRouting

(

)

[virtual]

Returns:

The value to be written to the module field of a routing mux.

Implements DigitalSource.

UINT32 AnalogTriggerOutput::GetChannelForRouting

(

)

[virtual]

Returns:

The value to be written to the channel field of a routing mux.

Implements DigitalSource.

UINT32 AnalogTriggerOutput::GetModuleForRouting

(

)

[virtual]

Returns:

The value to be written to the module field of a routing mux.

Implements DigitalSource.

void AnalogTriggerOutput::RequestInterrupts

(

)

[virtual]

Synchronus Wait version.

Request interrupts synchronously on this analog trigger output. TODO: Hardware supports interrupts on Analog Trigger outputs... WPILib should too

Implements DigitalSource.

void AnalogTriggerOutput::RequestInterrupts	(	tInterruptHandler	handler,
		void *	param = NULL
	)		[virtual]

Asynchronus handler version.

Request interrupts asynchronously on this analog trigger output. TODO: Hardware supports interrupts on Analog Trigger outputs... WPILib should too

Implements DigitalSource.

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

• AnalogTriggerOutput.h
• AnalogTriggerOutput.cpp