diff --git a/wpilibc/simulation/include/CounterBase.h b/wpilibc/simulation/include/CounterBase.h
new file mode 100644
index 0000000..3352c29
--- /dev/null
+++ b/wpilibc/simulation/include/CounterBase.h
@@ -0,0 +1,33 @@
+/*----------------------------------------------------------------------------*/
+/* 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.  */
+/*----------------------------------------------------------------------------*/
+#pragma once
+
+/**
+ * Interface for counting the number of ticks on a digital input channel.
+ * Encoders, Gear tooth sensors, and counters should all subclass this so it can be used to
+ * build more advanced classes for control and driving.
+ *
+ * All counters will immediately start counting - Reset() them if you need them
+ * to be zeroed before use.
+ */
+class CounterBase
+{
+public:
+	enum EncodingType
+	{
+		k1X,
+		k2X,
+		k4X
+	};
+
+	virtual ~CounterBase() = default;
+	virtual int32_t Get() const = 0;
+	virtual void Reset() = 0;
+	virtual double GetPeriod() const = 0;
+	virtual void SetMaxPeriod(double maxPeriod) = 0;
+	virtual bool GetStopped() const = 0;
+	virtual bool GetDirection() const = 0;
+};