Files
allwpilib/wpilibc/Athena/include/Ultrasonic.h
Tyler Veness 055ee09825 Fixed current and potential bugs caught by Coverity
Change-Id: I9f9d09dc797ffea062eeb49c881be1d5acb63d7b
2015-11-28 11:08:12 -08:00

111 lines
3.8 KiB
C++

/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2008. 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 $(WIND_BASE)/WPILib. */
/*----------------------------------------------------------------------------*/
#pragma once
#include "SensorBase.h"
#include "Counter.h"
#include "Task.h"
#include "PIDSource.h"
#include "LiveWindow/LiveWindowSendable.h"
#include <atomic>
#include "HAL/cpp/priority_mutex.h"
#include <memory>
class DigitalInput;
class DigitalOutput;
/**
* Ultrasonic rangefinder class.
* The Ultrasonic rangefinder measures absolute distance based on the round-trip
* time
* of a ping generated by the controller. These sensors use two transducers, a
* speaker and
* a microphone both tuned to the ultrasonic range. A common ultrasonic sensor,
* the Daventech SRF04
* requires a short pulse to be generated on a digital channel. This causes the
* chirp to be
* emmitted. A second line becomes high as the ping is transmitted and goes low
* when
* the echo is received. The time that the line is high determines the round
* trip distance
* (time of flight).
*/
class Ultrasonic : public SensorBase,
public PIDSource,
public LiveWindowSendable {
public:
enum DistanceUnit { kInches = 0, kMilliMeters = 1 };
DEPRECATED(
"Raw pointers are deprecated; prefer either specifying the channel "
"numbers as integers or passing shared_ptrs.")
Ultrasonic(DigitalOutput *pingChannel, DigitalInput *echoChannel,
DistanceUnit units = kInches);
DEPRECATED(
"References are deprecated; prefer either specifying the channel numbers "
"as integers or passing shared_ptrs.")
Ultrasonic(DigitalOutput &pingChannel, DigitalInput &echoChannel,
DistanceUnit units = kInches);
Ultrasonic(std::shared_ptr<DigitalOutput> pingChannel,
std::shared_ptr<DigitalInput> echoChannel,
DistanceUnit units = kInches);
Ultrasonic(uint32_t pingChannel, uint32_t echoChannel,
DistanceUnit units = kInches);
virtual ~Ultrasonic();
void Ping();
bool IsRangeValid() const;
static void SetAutomaticMode(bool enabling);
double GetRangeInches() const;
double GetRangeMM() const;
bool IsEnabled() const { return m_enabled; }
void SetEnabled(bool enable) { m_enabled = enable; }
double PIDGet() override;
void SetPIDSourceType(PIDSourceType pidSource) override;
void SetDistanceUnits(DistanceUnit units);
DistanceUnit GetDistanceUnits() const;
void UpdateTable() override;
void StartLiveWindowMode() override;
void StopLiveWindowMode() override;
std::string GetSmartDashboardType() const override;
void InitTable(std::shared_ptr<ITable> subTable) override;
std::shared_ptr<ITable> GetTable() const override;
private:
void Initialize();
static void UltrasonicChecker();
static constexpr double kPingTime =
10 * 1e-6; ///< Time (sec) for the ping trigger pulse.
static const uint32_t kPriority =
64; ///< Priority that the ultrasonic round robin task runs.
static constexpr double kMaxUltrasonicTime =
0.1; ///< Max time (ms) between readings.
static constexpr double kSpeedOfSoundInchesPerSec = 1130.0 * 12.0;
static Task m_task; // task doing the round-robin automatic sensing
static Ultrasonic *m_firstSensor; // head of the ultrasonic sensor list
static std::atomic<bool> m_automaticEnabled; // automatic round robin mode
static priority_mutex m_mutex; // synchronize access to the list of sensors
std::shared_ptr<DigitalOutput> m_pingChannel;
std::shared_ptr<DigitalInput> m_echoChannel;
bool m_enabled = false;
Counter m_counter;
Ultrasonic *m_nextSensor;
DistanceUnit m_units;
std::shared_ptr<ITable> m_table;
};