wpilibc/sim/src/PWM.cpp

/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2008-2017. 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.                                                               */
/*----------------------------------------------------------------------------*/

#include "PWM.h"

#include <sstream>

#include "Utility.h"
#include "WPIErrors.h"

using namespace frc;

const double PWM::kDefaultPwmPeriod = 5.05;
const double PWM::kDefaultPwmCenter = 1.5;
const int PWM::kDefaultPwmStepsDown = 1000;
const int PWM::kPwmDisabled = 0;

/**
 * Allocate a PWM given a channel number.
 *
 * Checks channel value range and allocates the appropriate channel.
 * The allocation is only done to help users ensure that they don't double
 * assign channels.
 *
 * @param channel The PWM channel number. 0-9 are on-board, 10-19 are on the MXP
 *                port
 */
PWM::PWM(int channel) {
  std::stringstream ss;

  if (!CheckPWMChannel(channel)) {
    ss << "PWM Channel " << channel;
    wpi_setWPIErrorWithContext(ChannelIndexOutOfRange, ss.str());
    return;
  }

  ss << "pwm/" << channel;
  impl = new SimContinuousOutput(ss.str());
  m_channel = channel;
  m_eliminateDeadband = false;

  m_centerPwm = kPwmDisabled;  // In simulation, the same thing.
}

PWM::~PWM() {
  if (m_table != nullptr) m_table->RemoveTableListener(this);
}

/**
 * Optionally eliminate the deadband from a speed controller.
 *
 * @param eliminateDeadband If true, set the motor curve on the Jaguar to
 *                          eliminate the deadband in the middle of the range.
 *                          Otherwise, keep the full range without modifying
 *                          any values.
 */
void PWM::EnableDeadbandElimination(bool eliminateDeadband) {
  m_eliminateDeadband = eliminateDeadband;
}

/**
 * Set the bounds on the PWM values.
 *
 * This sets the bounds on the PWM values for a particular each type of
 * controller. The values determine the upper and lower speeds as well as the
 * deadband bracket.
 *
 * @param max         The Minimum pwm value
 * @param deadbandMax The high end of the deadband range
 * @param center      The center speed (off)
 * @param deadbandMin The low end of the deadband range
 * @param min         The minimum pwm value
 */
void PWM::SetBounds(int max, int deadbandMax, int center, int deadbandMin,
                    int min) {
  // Nothing to do in simulation.
}

/**
 * Set the bounds on the PWM pulse widths.
 *
 * This sets the bounds on the PWM values for a particular type of controller.
 * The values determine the upper and lower speeds as well as the deadband
 * bracket.
 *
 * @param max         The max PWM pulse width in ms
 * @param deadbandMax The high end of the deadband range pulse width in ms
 * @param center      The center (off) pulse width in ms
 * @param deadbandMin The low end of the deadband pulse width in ms
 * @param min         The minimum pulse width in ms
 */
void PWM::SetBounds(double max, double deadbandMax, double center,
                    double deadbandMin, double min) {
  // Nothing to do in simulation.
}

/**
 * Set the PWM value based on a position.
 *
 * This is intended to be used by servos.
 *
 * @pre SetMaxPositivePwm() called.
 * @pre SetMinNegativePwm() called.
 *
 * @param pos The position to set the servo between 0.0 and 1.0.
 */
void PWM::SetPosition(double pos) {
  if (pos < 0.0) {
    pos = 0.0;
  } else if (pos > 1.0) {
    pos = 1.0;
  }

  impl->Set(pos);
}

/**
 * Get the PWM value in terms of a position.
 *
 * This is intended to be used by servos.
 *
 * @pre SetMaxPositivePwm() called.
 * @pre SetMinNegativePwm() called.
 *
 * @return The position the servo is set to between 0.0 and 1.0.
 */
double PWM::GetPosition() const {
  double value = impl->Get();
  if (value < 0.0) {
    return 0.0;
  } else if (value > 1.0) {
    return 1.0;
  } else {
    return value;
  }
}

/**
 * Set the PWM value based on a speed.
 *
 * This is intended to be used by speed controllers.
 *
 * @pre SetMaxPositivePwm() called.
 * @pre SetMinPositivePwm() called.
 * @pre SetCenterPwm() called.
 * @pre SetMaxNegativePwm() called.
 * @pre SetMinNegativePwm() called.
 *
 * @param speed The speed to set the speed controller between -1.0 and 1.0.
 */
void PWM::SetSpeed(double speed) {
  // clamp speed to be in the range 1.0 >= speed >= -1.0
  if (speed < -1.0) {
    speed = -1.0;
  } else if (speed > 1.0) {
    speed = 1.0;
  }

  impl->Set(speed);
}

/**
 * Get the PWM value in terms of speed.
 *
 * This is intended to be used by speed controllers.
 *
 * @pre SetMaxPositivePwm() called.
 * @pre SetMinPositivePwm() called.
 * @pre SetMaxNegativePwm() called.
 * @pre SetMinNegativePwm() called.
 *
 * @return The most recently set speed between -1.0 and 1.0.
 */
double PWM::GetSpeed() const {
  double value = impl->Get();
  if (value > 1.0) {
    return 1.0;
  } else if (value < -1.0) {
    return -1.0;
  } else {
    return value;
  }
}

/**
 * Set the PWM value directly to the hardware.
 *
 * Write a raw value to a PWM channel.
 *
 * @param value Raw PWM value.
 */
void PWM::SetRaw(uint16_t value) {
  wpi_assert(value == kPwmDisabled);
  impl->Set(0);
}

/**
 * Slow down the PWM signal for old devices.
 *
 * @param mult The period multiplier to apply to this channel
 */
void PWM::SetPeriodMultiplier(PeriodMultiplier mult) {
  // Do nothing in simulation.
}

void PWM::ValueChanged(ITable* source, llvm::StringRef key,
                       std::shared_ptr<nt::Value> value, bool isNew) {
  if (!value->IsDouble()) return;
  SetSpeed(value->GetDouble());
}

void PWM::UpdateTable() {
  if (m_table != nullptr) {
    m_table->PutNumber("Value", GetSpeed());
  }
}

void PWM::StartLiveWindowMode() {
  SetSpeed(0);
  if (m_table != nullptr) {
    m_table->AddTableListener("Value", this, true);
  }
}

void PWM::StopLiveWindowMode() {
  SetSpeed(0);
  if (m_table != nullptr) {
    m_table->RemoveTableListener(this);
  }
}

std::string PWM::GetSmartDashboardType() const { return "Speed Controller"; }

void PWM::InitTable(std::shared_ptr<ITable> subTable) {
  m_table = subTable;
  UpdateTable();
}

std::shared_ptr<ITable> PWM::GetTable() const { return m_table; }