Package edu.wpi.first.wpilibj

Class DutyCycleEncoder

java.lang.Object
edu.wpi.first.wpilibj.DutyCycleEncoder
All Implemented Interfaces:
Sendable, AutoCloseable
public class DutyCycleEncoder extends Object implements Sendable, AutoCloseable
Class for supporting duty cycle/PWM encoders, such as the US Digital MA3 with PWM Output, the CTRE Mag Encoder, the Rev Hex Encoder, and the AM Mag Encoder.

  • Constructor Details

    • DutyCycleEncoder

      public DutyCycleEncoder(int channel, double fullRange, double expectedZero)
      Construct a new DutyCycleEncoder on a specific channel.
      Parameters:
      channel - the channel to attach to
      fullRange - the value to report at maximum travel
      expectedZero - the reading where you would expect a 0 from get()

    • DutyCycleEncoder

      public DutyCycleEncoder(DutyCycle dutyCycle, double fullRange, double expectedZero)
      Construct a new DutyCycleEncoder attached to an existing DutyCycle object.
      Parameters:
      dutyCycle - the duty cycle to attach to
      fullRange - the value to report at maximum travel
      expectedZero - the reading where you would expect a 0 from get()

    • DutyCycleEncoder

      public DutyCycleEncoder(DigitalSource source, double fullRange, double expectedZero)
      Construct a new DutyCycleEncoder attached to a DigitalSource object.
      Parameters:
      source - the digital source to attach to
      fullRange - the value to report at maximum travel
      expectedZero - the reading where you would expect a 0 from get()

    • DutyCycleEncoder

      public DutyCycleEncoder(int channel)
      Construct a new DutyCycleEncoder on a specific channel.

      This has a fullRange of 1 and an expectedZero of 0.

      Parameters:
      channel - the channel to attach to

    • DutyCycleEncoder

      public DutyCycleEncoder(DutyCycle dutyCycle)
      Construct a new DutyCycleEncoder attached to an existing DutyCycle object.

      This has a fullRange of 1 and an expectedZero of 0.

      Parameters:
      dutyCycle - the duty cycle to attach to

    • DutyCycleEncoder

      public DutyCycleEncoder(DigitalSource source)
      Construct a new DutyCycleEncoder attached to a DigitalSource object.

      This has a fullRange of 1 and an expectedZero of 0.

      Parameters:
      source - the digital source to attach to

  • Method Details

    • get

      public double get()
      Get the encoder value since the last reset.

      This is reported in rotations since the last reset.

      Returns:
      the encoder value in rotations

    • setDutyCycleRange

      public void setDutyCycleRange(double min, double max)
      Set the encoder duty cycle range. As the encoder needs to maintain a duty cycle, the duty cycle cannot go all the way to 0% or all the way to 100%. For example, an encoder with a 4096 us period might have a minimum duty cycle of 1 us / 4096 us and a maximum duty cycle of 4095 / 4096 us. Setting the range will result in an encoder duty cycle less than or equal to the minimum being output as 0 rotation, the duty cycle greater than or equal to the maximum being output as 1 rotation, and values in between linearly scaled from 0 to 1.
      Parameters:
      min - minimum duty cycle (0-1 range)
      max - maximum duty cycle (0-1 range)

    • getFrequency

      public int getFrequency()
      Get the frequency in Hz of the duty cycle signal from the encoder.
      Returns:
      duty cycle frequency in Hz

    • isConnected

      public boolean isConnected()
      Get if the sensor is connected

      This uses the duty cycle frequency to determine if the sensor is connected. By default, a value of 100 Hz is used as the threshold, and this value can be changed with setConnectedFrequencyThreshold(int).

      Returns:
      true if the sensor is connected

    • setConnectedFrequencyThreshold

      public void setConnectedFrequencyThreshold(int frequency)
      Change the frequency threshold for detecting connection used by isConnected().
      Parameters:
      frequency - the minimum frequency in Hz.

    • setAssumedFrequency

      public void setAssumedFrequency(double frequency)
      Sets the assumed frequency of the connected device.

      By default, the DutyCycle engine has to compute the frequency of the input signal. This can result in both delayed readings and jumpy readings. To solve this, you can pass the expected frequency of the sensor to this function. This will use that frequency to compute the DutyCycle percentage, rather than the computed frequency.

      Parameters:
      frequency - the assumed frequency of the sensor

    • setInverted

      public void setInverted(boolean inverted)
      Set if this encoder is inverted.
      Parameters:
      inverted - true to invert the encoder, false otherwise

    • close

      public void close()
      Specified by:
      close in interface AutoCloseable

    • getFPGAIndex

      public int getFPGAIndex()
      Get the FPGA index for the DutyCycleEncoder.
      Returns:
      the FPGA index

    • getSourceChannel

      public int getSourceChannel()
      Get the channel of the source.
      Returns:
      the source channel

    • initSendable

      public void initSendable(SendableBuilder builder)
      Description copied from interface: Sendable
      Initializes this Sendable object.
      Specified by:
      initSendable in interface Sendable
      Parameters:
      builder - sendable builder