edu.wpi.first.wpilibj

Class PWM

java.lang.Object

edu.wpi.first.wpilibj.SensorBase

edu.wpi.first.wpilibj.PWM

All Implemented Interfaces:

LiveWindowSendable, Sendable

Direct Known Subclasses:

SafePWM, Servo

public class PWM
extends SensorBase
implements LiveWindowSendable

Class implements the PWM generation in the FPGA.

The values supplied as arguments for PWM outputs range from -1.0 to 1.0. They are mapped to the hardware dependent values, in this case 0-2000 for the FPGA. Changes are immediately sent to the FPGA, and the update occurs at the next FPGA cycle. There is no delay.

As of revision 0.1.10 of the FPGA, the FPGA interprets the 0-2000 values as follows: - 2000 = maximum pulse width - 1999 to 1001 = linear scaling from "full forward" to "center" - 1000 = center value - 999 to 2 = linear scaling from "center" to "full reverse" - 1 = minimum pulse width (currently .5ms) - 0 = disabled (i.e. PWM output is held low)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PWM.PeriodMultiplier Represents the amount to multiply the minimum servo-pulse pwm period by.

Field Summary

Fields inherited from class edu.wpi.first.wpilibj.SensorBase

kAnalogInputChannels, kAnalogOutputChannels, kDigitalChannels, kPCMModules, kPDPChannels, kPDPModules, kPwmChannels, kRelayChannels, kSolenoidChannels, kSystemClockTicksPerMicrosecond

Constructor Summary

Constructors

Constructor and Description
PWM(int channel) Allocate a PWM given a channel.

Method Summary

Modifier and Type	Method and Description
void	enableDeadbandElimination(boolean eliminateDeadband) Optionally eliminate the deadband from a speed controller.
void	free() Free the PWM channel.
int	getChannel() Gets the channel number associated with the PWM Object.
double	getPosition() Get the PWM value in terms of a position.
int	getRaw() Get the PWM value directly from the hardware.
PWMConfigDataResult	getRawBounds() Gets the bounds on the PWM pulse widths.
java.lang.String	getSmartDashboardType() The string representation of the named data type that will be used by the smart dashboard for this Sendable.
double	getSpeed() Get the PWM value in terms of speed.
ITable	getTable() The table that is associated with this Sendable.
void	initTable(ITable subtable) Initializes a table for this Sendable object.
void	setBounds(double max, double deadbandMax, double center, double deadbandMin, double min) Set the bounds on the PWM pulse widths.
void	setDisabled() Temporarily disables the PWM output.
void	setPeriodMultiplier(PWM.PeriodMultiplier mult) Slow down the PWM signal for old devices.
void	setPosition(double pos) Set the PWM value based on a position.
void	setRaw(int value) Set the PWM value directly to the hardware.
void	setRawBounds(int max, int deadbandMax, int center, int deadbandMin, int min) Deprecated. Recommended to set bounds in ms using setBounds(double, double, double, double, double)
void	setSpeed(double speed) Set the PWM value based on a speed.
protected void	setZeroLatch()
void	startLiveWindowMode() Start having this sendable object automatically respond to value changes reflect the value on the table.
void	stopLiveWindowMode() Stop having this sendable object automatically respond to value changes.
void	updateTable() Update the table for this sendable object with the latest values.

Methods inherited from class edu.wpi.first.wpilibj.SensorBase

checkAnalogInputChannel, checkAnalogOutputChannel, checkDigitalChannel, checkPDPChannel, checkPDPModule, checkPWMChannel, checkRelayChannel, checkSolenoidChannel, checkSolenoidModule, getDefaultSolenoidModule, setDefaultSolenoidModule

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PWM

public PWM(int channel)

Allocate a PWM given a channel.

Parameters:

channel - The PWM channel number. 0-9 are on-board, 10-19 are on the MXP port

Method Detail

free

public void free()

Free the PWM channel.

Free the resource associated with the PWM channel and set the value to 0.

Overrides:

free in class SensorBase

enableDeadbandElimination

public void enableDeadbandElimination(boolean eliminateDeadband)

Optionally eliminate the deadband from a speed controller.

Parameters:

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.

setRawBounds

@Deprecated
public void setRawBounds(int max,
                                      int deadbandMax,
                                      int center,
                                      int deadbandMin,
                                      int min)

Deprecated. Recommended to set bounds in ms using setBounds(double, double, double, double, double)

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.

Parameters:

max - The Minimum pwm value

deadbandMax - The high end of the deadband range

center - The center speed (off)

deadbandMin - The low end of the deadband range

min - The minimum pwm value

setBounds

public void setBounds(double max,
                      double deadbandMax,
                      double center,
                      double deadbandMin,
                      double min)

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.

Parameters:

max - The max PWM pulse width in ms

deadbandMax - The high end of the deadband range pulse width in ms

center - The center (off) pulse width in ms

deadbandMin - The low end of the deadband pulse width in ms

min - The minimum pulse width in ms

getRawBounds

public PWMConfigDataResult getRawBounds()

Gets the bounds on the PWM pulse widths. This Gets 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.

getChannel

public int getChannel()

Gets the channel number associated with the PWM Object.

Returns:

The channel number.

setPosition

public void setPosition(double pos)

Set the PWM value based on a position.

This is intended to be used by servos.

Parameters:

pos - The position to set the servo between 0.0 and 1.0.

getPosition

public double getPosition()

Get the PWM value in terms of a position.

This is intended to be used by servos.

Returns:

The position the servo is set to between 0.0 and 1.0.

setSpeed

public void setSpeed(double speed)

Set the PWM value based on a speed.

This is intended to be used by speed controllers.

Parameters:

speed - The speed to set the speed controller between -1.0 and 1.0.

getSpeed

public double getSpeed()

Get the PWM value in terms of speed.

This is intended to be used by speed controllers.

Returns:

The most recently set speed between -1.0 and 1.0.

setRaw

public void setRaw(int value)

Set the PWM value directly to the hardware.

Write a raw value to a PWM channel.

Parameters:

value - Raw PWM value. Range 0 - 255.

getRaw

public int getRaw()

Get the PWM value directly from the hardware.

Read a raw value from a PWM channel.

Returns:

Raw PWM control value. Range: 0 - 255.

setDisabled

public void setDisabled()

Temporarily disables the PWM output. The next set call will reenable the output.

setPeriodMultiplier

public void setPeriodMultiplier(PWM.PeriodMultiplier mult)

Slow down the PWM signal for old devices.

Parameters:

mult - The period multiplier to apply to this channel

setZeroLatch

protected void setZeroLatch()

getSmartDashboardType

public java.lang.String getSmartDashboardType()

Description copied from interface: Sendable

The string representation of the named data type that will be used by the smart dashboard for this Sendable.

Specified by:

getSmartDashboardType in interface Sendable

Returns:

The type of this Sendable.

initTable

public void initTable(ITable subtable)

Description copied from interface: Sendable

Initializes a table for this Sendable object.

Specified by:

initTable in interface Sendable

Parameters:

subtable - The table to put the values in.

updateTable

public void updateTable()

Description copied from interface: LiveWindowSendable

Update the table for this sendable object with the latest values.

Specified by:

updateTable in interface LiveWindowSendable

getTable

public ITable getTable()

Description copied from interface: Sendable

The table that is associated with this Sendable.

Specified by:

getTable in interface Sendable

Returns:

the table that is currently associated with the Sendable.

startLiveWindowMode

public void startLiveWindowMode()

Description copied from interface: LiveWindowSendable

Start having this sendable object automatically respond to value changes reflect the value on the table.

Specified by:

startLiveWindowMode in interface LiveWindowSendable

stopLiveWindowMode

public void stopLiveWindowMode()

Description copied from interface: LiveWindowSendable

Stop having this sendable object automatically respond to value changes.

Specified by:

stopLiveWindowMode in interface LiveWindowSendable