Added ahal
This is a formatted copy of WPILib's default user-visible C++ API, with
a bit of completely unnecessary functionality stripped out. Most of the
stripping so far is only related to weird threading decisions.
Change-Id: Icbfd949b48cd115561862cb909bcc572aba0e753
diff --git a/frc971/wpilib/ahal/Encoder.cc b/frc971/wpilib/ahal/Encoder.cc
new file mode 100644
index 0000000..8d57eda
--- /dev/null
+++ b/frc971/wpilib/ahal/Encoder.cc
@@ -0,0 +1,162 @@
+/*----------------------------------------------------------------------------*/
+/* 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/Encoder.h"
+
+#include "HAL/HAL.h"
+#include "frc971/wpilib/ahal/DigitalInput.h"
+
+using namespace frc;
+
+#define HAL_FATAL_WITH_STATUS(status)
+
+/**
+ * Common initialization code for Encoders.
+ *
+ * This code allocates resources for Encoders and is common to all constructors.
+ *
+ * The counter will start counting immediately.
+ *
+ * @param reverseDirection If true, counts down instead of up (this is all
+ * relative)
+ * @param encodingType either k1X, k2X, or k4X to indicate 1X, 2X or 4X
+ * decoding. If 4X is selected, then an encoder FPGA
+ * object is used and the returned counts will be 4x
+ * the encoder spec'd value since all rising and
+ * falling edges are counted. If 1X or 2X are selected
+ * then a counter object will be used and the returned
+ * value will either exactly match the spec'd count or
+ * be double (2x) the spec'd count.
+ */
+void Encoder::InitEncoder(bool reverseDirection, EncodingType encodingType) {
+ int32_t status = 0;
+ m_encoder = HAL_InitializeEncoder(
+ m_aSource->GetPortHandleForRouting(),
+ (HAL_AnalogTriggerType)m_aSource->GetAnalogTriggerTypeForRouting(),
+ m_bSource->GetPortHandleForRouting(),
+ (HAL_AnalogTriggerType)m_bSource->GetAnalogTriggerTypeForRouting(),
+ reverseDirection, (HAL_EncoderEncodingType)encodingType, &status);
+ HAL_FATAL_WITH_STATUS(status);
+
+ HAL_Report(HALUsageReporting::kResourceType_Encoder, GetFPGAIndex(),
+ encodingType);
+}
+
+/**
+ * Encoder constructor.
+ *
+ * Construct a Encoder given a and b channels.
+ *
+ * The counter will start counting immediately.
+ *
+ * @param aChannel The a channel DIO channel. 0-9 are on-board, 10-25
+ * are on the MXP port
+ * @param bChannel The b channel DIO channel. 0-9 are on-board, 10-25
+ * are on the MXP port
+ * @param reverseDirection represents the orientation of the encoder and
+ * inverts the output values if necessary so forward
+ * represents positive values.
+ * @param encodingType either k1X, k2X, or k4X to indicate 1X, 2X or 4X
+ * decoding. If 4X is selected, then an encoder FPGA
+ * object is used and the returned counts will be 4x
+ * the encoder spec'd value since all rising and
+ * falling edges are counted. If 1X or 2X are selected
+ * then a counter object will be used and the returned
+ * value will either exactly match the spec'd count or
+ * be double (2x) the spec'd count.
+ */
+Encoder::Encoder(int aChannel, int bChannel, bool reverseDirection,
+ EncodingType encodingType) {
+ m_aSource = std::make_shared<DigitalInput>(aChannel);
+ m_bSource = std::make_shared<DigitalInput>(bChannel);
+ InitEncoder(reverseDirection, encodingType);
+}
+
+/**
+ * Free the resources for an Encoder.
+ *
+ * Frees the FPGA resources associated with an Encoder.
+ */
+Encoder::~Encoder() {
+ int32_t status = 0;
+ HAL_FreeEncoder(m_encoder, &status);
+ HAL_FATAL_WITH_STATUS(status);
+}
+
+/**
+ * The encoding scale factor 1x, 2x, or 4x, per the requested encodingType.
+ *
+ * Used to divide raw edge counts down to spec'd counts.
+ */
+int Encoder::GetEncodingScale() const {
+ int32_t status = 0;
+ int val = HAL_GetEncoderEncodingScale(m_encoder, &status);
+ wpi_setErrorWithContext(status, HAL_GetErrorMessage(status));
+ return val;
+}
+
+/**
+ * Gets the raw value from the encoder.
+ *
+ * The raw value is the actual count unscaled by the 1x, 2x, or 4x scale
+ * factor.
+ *
+ * @return Current raw count from the encoder
+ */
+int Encoder::GetRaw() const {
+ int32_t status = 0;
+ int value = HAL_GetEncoderRaw(m_encoder, &status);
+ HAL_FATAL_WITH_STATUS(status);
+ return value;
+}
+
+/**
+ * Returns the period of the most recent pulse.
+ *
+ * Returns the period of the most recent Encoder pulse in seconds.
+ * This method compensates for the decoding type.
+ *
+ * @deprecated Use GetRate() in favor of this method. This returns unscaled
+ * periods and GetRate() scales using value from
+ * SetDistancePerPulse().
+ *
+ * @return Period in seconds of the most recent pulse.
+ */
+double Encoder::GetPeriod() const {
+ int32_t status = 0;
+ double value = HAL_GetEncoderPeriod(m_encoder, &status);
+ HAL_FATAL_WITH_STATUS(status);
+ return value;
+}
+/**
+ * Sets the maximum period for stopped detection.
+ *
+ * Sets the value that represents the maximum period of the Encoder before it
+ * will assume that the attached device is stopped. This timeout allows users
+ * to determine if the wheels or other shaft has stopped rotating.
+ * This method compensates for the decoding type.
+ *
+ * @deprecated Use SetMinRate() in favor of this method. This takes unscaled
+ * periods and SetMinRate() scales using value from
+ * SetDistancePerPulse().
+ *
+ * @param maxPeriod The maximum time between rising and falling edges before
+ * the FPGA will report the device stopped. This is expressed
+ * in seconds.
+ */
+void Encoder::SetMaxPeriod(double maxPeriod) {
+ int32_t status = 0;
+ HAL_SetEncoderMaxPeriod(m_encoder, maxPeriod, &status);
+ HAL_FATAL_WITH_STATUS(status);
+}
+
+int Encoder::GetFPGAIndex() const {
+ int32_t status = 0;
+ int val = HAL_GetEncoderFPGAIndex(m_encoder, &status);
+ HAL_FATAL_WITH_STATUS(status);
+ return val;
+}