Package ca.retrylife.frc.templates.arms

Class SensorlessArm

java.lang.Object

edu.wpi.first.wpilibj2.command.SubsystemBase

ca.retrylife.frc.templates.arms.SensorlessArm

All Implemented Interfaces:

Sendable, Subsystem

public class SensorlessArm
extends SubsystemBase

The SensorlessArm class is designed to control any type of arm that does not have a rotational sensor (like an encoder or potentiometer). At 5024, we have used these in 2019 (climber) and 2020 (intake). The physical system must consist of an arm that can be in one of two positions, and a limit switch (or other digital input) at each stopping point. Since there is no good sensor for this system, a strong motor must be used, otherwise the arm will not hold its position at all. If the arm needs to hold position, add an encoder.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SensorlessArm.SystemState

Constructor Summary

Constructors

Constructor	Description
SensorlessArm(SpeedController motor, DigitalInput loweredLimitSensor, DigitalInput raisedLimitSensor, double speed, double feedForward)	Create a SensorlessArm

Method Summary

Modifier and Type	Method	Description
SensorlessArm.SystemState	getLastKnownPosition()	Get the last known position of the arm
void	periodic()
void	setDesiredPosition(SensorlessArm.SystemState position)	Set the desired position for the arm
void	stop()	Stop the arm

Methods inherited from class edu.wpi.first.wpilibj2.command.SubsystemBase

addChild, getName, getSubsystem, initSendable, setName, setSubsystem

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.wpi.first.wpilibj.Sendable

addChild, setName, setName, setName

Methods inherited from interface edu.wpi.first.wpilibj2.command.Subsystem

getCurrentCommand, getDefaultCommand, register, setDefaultCommand, simulationPeriodic

Constructor Detail

SensorlessArm

public SensorlessArm(SpeedController motor,
                     DigitalInput loweredLimitSensor,
                     DigitalInput raisedLimitSensor,
                     double speed,
                     double feedForward)

Create a SensorlessArm

Parameters:

motor - Arm motor

loweredLimitSensor - Limit sensor at the bottom of the arm's range of motion

raisedLimitSensor - Limit sensor at the top of the arm's range of motion

speed - How fast the arm should move downwards as a percentage output

feedForward - How much faster the arm should move going up than it should going down

Method Detail

periodic

public void periodic()

setDesiredPosition

public void setDesiredPosition(SensorlessArm.SystemState position)

Set the desired position for the arm

Parameters:

position - Desired position

getLastKnownPosition

public SensorlessArm.SystemState getLastKnownPosition()

Get the last known position of the arm

Returns:

Last position

stop

public void stop()

Stop the arm