diff --git a/wpilibc/athena/include/Encoder.h b/wpilibc/athena/include/Encoder.h
new file mode 100644
index 0000000..f429703
--- /dev/null
+++ b/wpilibc/athena/include/Encoder.h
@@ -0,0 +1,111 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <memory>
+#include <string>
+
+#include "Counter.h"
+#include "CounterBase.h"
+#include "HAL/Encoder.h"
+#include "LiveWindow/LiveWindowSendable.h"
+#include "PIDSource.h"
+#include "SensorBase.h"
+
+namespace frc {
+
+class DigitalSource;
+class DigitalGlitchFilter;
+
+/**
+ * Class to read quad encoders.
+ * Quadrature encoders are devices that count shaft rotation and can sense
+ * direction. The output of the QuadEncoder class is an integer that can count
+ * either up or down, and can go negative for reverse direction counting. When
+ * creating QuadEncoders, a direction is supplied that changes the sense of the
+ * output to make code more readable if the encoder is mounted such that forward
+ * movement generates negative values. Quadrature encoders have two digital
+ * outputs, an A Channel and a B Channel that are out of phase with each other
+ * to allow the FPGA to do direction sensing.
+ *
+ * All encoders will immediately start counting - Reset() them if you need them
+ * to be zeroed before use.
+ */
+class Encoder : public SensorBase,
+                public CounterBase,
+                public PIDSource,
+                public LiveWindowSendable {
+ public:
+  enum IndexingType {
+    kResetWhileHigh,
+    kResetWhileLow,
+    kResetOnFallingEdge,
+    kResetOnRisingEdge
+  };
+
+  Encoder(int aChannel, int bChannel, bool reverseDirection = false,
+          EncodingType encodingType = k4X);
+  Encoder(std::shared_ptr<DigitalSource> aSource,
+          std::shared_ptr<DigitalSource> bSource, bool reverseDirection = false,
+          EncodingType encodingType = k4X);
+  Encoder(DigitalSource* aSource, DigitalSource* bSource,
+          bool reverseDirection = false, EncodingType encodingType = k4X);
+  Encoder(DigitalSource& aSource, DigitalSource& bSource,
+          bool reverseDirection = false, EncodingType encodingType = k4X);
+  virtual ~Encoder();
+
+  // CounterBase interface
+  int Get() const override;
+  int GetRaw() const;
+  int GetEncodingScale() const;
+  void Reset() override;
+  double GetPeriod() const override;
+  void SetMaxPeriod(double maxPeriod) override;
+  bool GetStopped() const override;
+  bool GetDirection() const override;
+
+  double GetDistance() const;
+  double GetRate() const;
+  void SetMinRate(double minRate);
+  void SetDistancePerPulse(double distancePerPulse);
+  void SetReverseDirection(bool reverseDirection);
+  void SetSamplesToAverage(int samplesToAverage);
+  int GetSamplesToAverage() const;
+  double PIDGet() override;
+
+  void SetIndexSource(int channel, IndexingType type = kResetOnRisingEdge);
+  WPI_DEPRECATED("Use pass-by-reference instead.")
+  void SetIndexSource(DigitalSource* source,
+                      IndexingType type = kResetOnRisingEdge);
+  void SetIndexSource(const DigitalSource& source,
+                      IndexingType type = kResetOnRisingEdge);
+
+  void UpdateTable() override;
+  void StartLiveWindowMode() override;
+  void StopLiveWindowMode() override;
+  std::string GetSmartDashboardType() const override;
+  void InitTable(std::shared_ptr<ITable> subTable) override;
+  std::shared_ptr<ITable> GetTable() const override;
+
+  int GetFPGAIndex() const;
+
+ private:
+  void InitEncoder(bool reverseDirection, EncodingType encodingType);
+
+  double DecodingScaleFactor() const;
+
+  std::shared_ptr<DigitalSource> m_aSource;  // the A phase of the quad encoder
+  std::shared_ptr<DigitalSource> m_bSource;  // the B phase of the quad encoder
+  std::unique_ptr<DigitalSource> m_indexSource = nullptr;
+  HAL_EncoderHandle m_encoder = HAL_kInvalidHandle;
+
+  std::shared_ptr<ITable> m_table;
+  friend class DigitalGlitchFilter;
+};
+
+}  // namespace frc