clean up the organization of + split out wpilib_interface

Change-Id: I5278e42d13c4bb46619e52e20a72e8e878863ed0
diff --git a/frc971/wpilib/hall_effect.h b/frc971/wpilib/hall_effect.h
new file mode 100644
index 0000000..8a088c3
--- /dev/null
+++ b/frc971/wpilib/hall_effect.h
@@ -0,0 +1,18 @@
+#ifndef FRC971_WPILIB_HALL_EFFECT_H_
+#define FRC971_WPILIB_HALL_EFFECT_H_
+
+#include "DigitalInput.h"
+
+namespace frc971 {
+namespace wpilib {
+
+class HallEffect : public DigitalInput {
+ public:
+  HallEffect(int index) : DigitalInput(index) {}
+  bool GetHall() { return !Get(); }
+};
+
+}  // namespace wpilib
+}  // namespace frc971
+
+#endif // FRC971_WPILIB_HALL_EFFECT_H_