mirror of
https://github.com/wpilibsuite/allwpilib
synced 2026-06-19 00:41:43 +00:00
66 lines
3.1 KiB
C++
66 lines
3.1 KiB
C++
/*----------------------------------------------------------------------------*/
|
|
/* Copyright (c) FIRST 2008-2016. All Rights Reserved. */
|
|
/* Open Source Software - may be modified and shared by FRC teams. The code */
|
|
/* must be accompanied by the FIRST BSD license file in the root directory of */
|
|
/* the project. */
|
|
/*----------------------------------------------------------------------------*/
|
|
|
|
#pragma once
|
|
|
|
#include "DigitalSource.h"
|
|
|
|
class AnalogTrigger;
|
|
|
|
/** 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.
|
|
*/
|
|
class AnalogTriggerOutput : public DigitalSource {
|
|
friend class AnalogTrigger;
|
|
|
|
public:
|
|
virtual ~AnalogTriggerOutput();
|
|
bool Get() const;
|
|
|
|
// DigitalSource interface
|
|
virtual uint32_t GetChannelForRouting() const override;
|
|
virtual uint32_t GetModuleForRouting() const override;
|
|
virtual bool GetAnalogTriggerForRouting() const override;
|
|
|
|
protected:
|
|
AnalogTriggerOutput(const AnalogTrigger& trigger,
|
|
AnalogTriggerType outputType);
|
|
|
|
private:
|
|
// Uses reference rather than smart pointer because a user can not construct
|
|
// an AnalogTriggerOutput themselves and because the AnalogTriggerOutput
|
|
// should always be in scope at the same time as an AnalogTrigger.
|
|
const AnalogTrigger& m_trigger;
|
|
AnalogTriggerType m_outputType;
|
|
};
|