diff --git a/wpilibc/Athena/src/GearTooth.cpp b/wpilibc/Athena/src/GearTooth.cpp
new file mode 100644
index 0000000..b659125
--- /dev/null
+++ b/wpilibc/Athena/src/GearTooth.cpp
@@ -0,0 +1,64 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2008. 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 $(WIND_BASE)/WPILib.  */
+/*----------------------------------------------------------------------------*/
+
+#include "GearTooth.h"
+#include "LiveWindow/LiveWindow.h"
+
+constexpr double GearTooth::kGearToothThreshold;
+
+/**
+ * Common code called by the constructors.
+ */
+void GearTooth::EnableDirectionSensing(bool directionSensitive) {
+  if (directionSensitive) {
+    SetPulseLengthMode(kGearToothThreshold);
+  }
+}
+
+/**
+ * Construct a GearTooth sensor given a channel.
+ *
+ * @param channel The DIO channel that the sensor is connected to. 0-9 are
+ * on-board, 10-25 are on the MXP.
+ * @param directionSensitive True to enable the pulse length decoding in
+ * hardware to specify count direction.
+ */
+GearTooth::GearTooth(uint32_t channel, bool directionSensitive)
+    : Counter(channel) {
+  EnableDirectionSensing(directionSensitive);
+  LiveWindow::GetInstance()->AddSensor("GearTooth", channel, this);
+}
+
+/**
+ * Construct a GearTooth sensor given a digital input.
+ * This should be used when sharing digital inputs.
+ *
+ * @param source A pointer to the existing DigitalSource object (such as a
+ * DigitalInput)
+ * @param directionSensitive True to enable the pulse length decoding in
+ * hardware to specify count direction.
+ */
+GearTooth::GearTooth(DigitalSource *source, bool directionSensitive)
+    : Counter(source) {
+  EnableDirectionSensing(directionSensitive);
+}
+
+/**
+ * Construct a GearTooth sensor given a digital input.
+ * This should be used when sharing digital inputs.
+ *
+ * @param source A reference to the existing DigitalSource object (such as a
+ * DigitalInput)
+ * @param directionSensitive True to enable the pulse length decoding in
+ * hardware to specify count direction.
+ */
+GearTooth::GearTooth(std::shared_ptr<DigitalSource> source, bool directionSensitive)
+    : Counter(source) {
+  EnableDirectionSensing(directionSensitive);
+}
+
+std::string GearTooth::GetSmartDashboardType() const { return "GearTooth"; }