/**
* Free the PWM channel.
*
* <p>Free the resource associated with the PWM channel and set the value to 0.
*/
public void free() {
if (m_port == 0) return;
PWMJNI.setPWM(m_port, (short) 0);
PWMJNI.freePWMChannel(m_port);
PWMJNI.freeDIO(m_port);
DIOJNI.freeDigitalPort(m_port);
m_port = 0;
}
/**
* Initialize PWMs given a channel.
*
* <p>This method is private and is the common path for all the constructors for creating PWM
* instances. Checks channel value ranges 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
*/
private void initPWM(final int channel) {
checkPWMChannel(channel);
m_channel = channel;
m_port = DIOJNI.initializeDigitalPort(DIOJNI.getPort((byte) m_channel));
if (!PWMJNI.allocatePWMChannel(m_port)) {
throw new AllocationException("PWM channel " + channel + " is already allocated");
}
PWMJNI.setPWM(m_port, (short) 0);
m_eliminateDeadband = false;
UsageReporting.report(tResourceType.kResourceType_PWM, channel);
}
/**
* Set the PWM value based on a speed.
*
* <p>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.
*/
final void 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;
}
// // calculate the desired output pwm value by scaling the speed
// appropriately
// int rawValue;
// if (speed == 0.0) {
// rawValue = getCenterPwm();
// } else if (speed > 0.0) {
// rawValue =
// (int) (speed * ((double) getPositiveScaleFactor()) + ((double)
// getMinPositivePwm()) + 0.5);
// } else {
// rawValue =
// (int) (speed * ((double) getNegativeScaleFactor()) + ((double)
// getMaxNegativePwm()) + 0.5);
// }
//
// // send the computed pwm value to the FPGA
// setRaw(rawValue);
// The above is too complicated to simulate, just fake it
PWMJNI.__setPWM(m_port, speed);
}
/**
* Slow down the PWM signal for old devices.
*
* @param mult The period multiplier to apply to this channel
*/
public void setPeriodMultiplier(PeriodMultiplier mult) {
switch (mult.value) {
case PeriodMultiplier.k4X_val:
// Squelch 3 out of 4 outputs
PWMJNI.setPWMPeriodScale(m_port, 3);
break;
case PeriodMultiplier.k2X_val:
// Squelch 1 out of 2 outputs
PWMJNI.setPWMPeriodScale(m_port, 1);
break;
case PeriodMultiplier.k1X_val:
// Don't squelch any outputs
PWMJNI.setPWMPeriodScale(m_port, 0);
break;
default:
// Cannot hit this, limited by PeriodMultiplier enum
}
}
/**
* Get the PWM value in terms of speed.
*
* <p>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.
*/
public double getSpeed() {
// int value = getRaw();
// if (value > getMaxPositivePwm()) {
// return 1.0;
// } else if (value < getMinNegativePwm()) {
// return -1.0;
// } else if (value > getMinPositivePwm()) {
// return (double) (value - getMinPositivePwm()) / (double)
// getPositiveScaleFactor();
// } else if (value < getMaxNegativePwm()) {
// return (double) (value - getMaxNegativePwm()) / (double)
// getNegativeScaleFactor();
// } else {
// return 0.0;
// }
// The above is too complicated to simulate, just fake it
return PWMJNI.__getPWM(m_port);
}
protected void setZeroLatch() {
PWMJNI.latchPWMZero(m_port);
}
/**
* Get the PWM value directly from the hardware.
*
* <p>Read a raw value from a PWM channel.
*
* @return Raw PWM control value. Range: 0 - 255.
*/
public int getRaw() {
return PWMJNI.getPWM(m_port);
}
/**
* Set the PWM value directly to the hardware.
*
* <p>Write a raw value to a PWM channel.
*
* @param value Raw PWM value. Range 0 - 255.
*/
public void setRaw(int value) {
PWMJNI.setPWM(m_port, (short) value);
}