Added a C++ built-in accelerometer class

Change-Id: I80cee788912277f06ac4bdda40261f160de0cbaa

wpilibc/wpilibC++IntegrationTests/src/AccelerometerTest.cpp

@@ -0,0 +1,23 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2014. 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 "WPILib.h"
+#include "gtest/gtest.h"
+
+static constexpr double accelerationTolerance = 0.1;
+
+/**
+ * There's not much we can automatically test with the on-board accelerometer,
+ * but checking for gravity is probably good enough to tell that it's working.
+ */
+TEST(AccelerometerTest, Accelerometer) {
+	BuiltInAccelerometer accelerometer;
+
+	ASSERT_NEAR(0.0, accelerometer.GetX(), accelerationTolerance);
+	ASSERT_NEAR(0.0, accelerometer.GetY(), accelerationTolerance);
+	ASSERT_NEAR(1.0, accelerometer.GetZ(), accelerationTolerance);
+}