AnalogTriggerOutput Class Reference

#include <AnalogTriggerOutput.h>

Inheritance diagram for AnalogTriggerOutput:

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Collaboration diagram for AnalogTriggerOutput:

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List of all members.

Public Member Functions

bool Get (void)
virtual unsigned GetChannelForRouting (void)
virtual unsigned GetModuleForRouting (void)
virtual bool GetAnalogTriggerForRouting (void)
virtual void RequestInterrupts (tInterruptHandler handler)
 Asynchronus handler version.
virtual void RequestInterrupts (void)
 Synchronus Wait version.

Protected Member Functions

 AnalogTriggerOutput (AnalogTrigger *trigger, Type outputType)


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.


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.


Member Function Documentation

bool AnalogTriggerOutput::Get ( void   ) 

Get the state of the analog trigger output.

Returns:
The state of the analog trigger output.

unsigned AnalogTriggerOutput::GetChannelForRouting ( void   )  [virtual]

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

Implements DigitalSource.

unsigned AnalogTriggerOutput::GetModuleForRouting ( void   )  [virtual]

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

Implements DigitalSource.

bool AnalogTriggerOutput::GetAnalogTriggerForRouting ( void   )  [virtual]

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

Implements DigitalSource.

void AnalogTriggerOutput::RequestInterrupts ( tInterruptHandler  handler  )  [virtual]

Asynchronus handler version.

Request interrupts asynchronously on this digital input.

Implements DigitalSource.

void AnalogTriggerOutput::RequestInterrupts ( void   )  [virtual]

Synchronus Wait version.

Request interrupts synchronously on this digital input.

Implements DigitalSource.


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

Generated on Thu Oct 2 14:01:22 2008 for WPI Robotics Library by  doxygen 1.5.5