Merge changes If91e63ce,I94daa069

* changes:
  Create CopyPosition function for RelativePosition.
  Create TalonFX motor contoller file in ahal.
diff --git a/frc971/wpilib/ahal/TalonFX.cc b/frc971/wpilib/ahal/TalonFX.cc
new file mode 100644
index 0000000..93dc62e
--- /dev/null
+++ b/frc971/wpilib/ahal/TalonFX.cc
@@ -0,0 +1,42 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "frc971/wpilib/ahal/TalonFX.h"
+
+#include "hal/HAL.h"
+
+using namespace frc;
+
+/**
+ * Constructor for a TalonFX.
+ *
+ * @param channel The PWM channel that the TalonFX is attached to. 0-9 are
+ *                on-board, 10-19 are on the MXP port
+ */
+TalonFX::TalonFX(int channel) : PWM(channel) {
+  /**
+   * Note that the TalonFX uses the following bounds for PWM values. These
+   * values should work reasonably well for most controllers, but if users
+   * experience issues such as asymmetric behavior around the deadband or
+   * inability to saturate the controller in either direction, calibration is
+   * recommended. The calibration procedure can be found in the TalonFX User
+   * Manual available from Vex.
+   *
+   *   2.004ms = full "forward"
+   *   1.52ms = the "high end" of the deadband range
+   *   1.50ms = center of the deadband range (off)
+   *   1.48ms = the "low end" of the deadband range
+   *   0.997ms = full "reverse"
+   */
+  SetBounds(2.004, 1.52, 1.50, 1.48, .997);
+  SetPeriodMultiplier(kPeriodMultiplier_1X);
+  SetSpeed(0.0);
+  SetZeroLatch();
+
+  HAL_Report(HALUsageReporting::kResourceType_VictorSP, GetChannel());
+}
+
diff --git a/frc971/wpilib/ahal/TalonFX.h b/frc971/wpilib/ahal/TalonFX.h
new file mode 100644
index 0000000..0de0019
--- /dev/null
+++ b/frc971/wpilib/ahal/TalonFX.h
@@ -0,0 +1,23 @@
+
+/* 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 "frc971/wpilib/ahal/PWM.h"
+
+namespace frc {
+
+/**
+ * Vex Robotics Victor SP Speed Controller
+ */
+class TalonFX : public PWM {
+ public:
+  explicit TalonFX(int channel);
+  virtual ~TalonFX() = default;
+};
+
+}  // namespace frc
diff --git a/frc971/wpilib/sensor_reader.h b/frc971/wpilib/sensor_reader.h
index 3e24fd7..25e7592 100644
--- a/frc971/wpilib/sensor_reader.h
+++ b/frc971/wpilib/sensor_reader.h
@@ -166,6 +166,18 @@
     position->index_pulses = encoder.index_posedge_count();
   }
 
+  // Copies a relative encoder.
+  void CopyPosition(const ::frc::Encoder &encoder,
+                    ::frc971::RelativePositionT *position,
+                    double encoder_counts_per_revolution, double encoder_ratio,
+                    bool reverse) {
+    const double multiplier = reverse ? -1.0 : 1.0;
+    position->encoder =
+        multiplier * encoder_translate(encoder.GetRaw(),
+                                       encoder_counts_per_revolution,
+                                       encoder_ratio);
+  }
+
   double encoder_translate(int32_t value, double counts_per_revolution,
                            double ratio) {
     return static_cast<double>(value) / counts_per_revolution * ratio *