grove: rotary angle sensor

Signed-off-by: Mihai Tudor Panu <mihai.t.panu@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

src/grove/grove.cxx

@@ -1,5 +1,6 @@
 /*
  * Author: Brendan Le Foll <brendan.le.foll@intel.com>
+ * Contributions: Mihai Tudor Panu <mihai.t.panu@intel.com>
  * Copyright (c) 2014 Intel Corporation.
  *
  * Permission is hereby granted, free of charge, to any person obtaining
@@ -115,3 +116,47 @@ float GroveLight::raw_value()
 {
     return (float) mraa_aio_read(m_aio);
 }
+
+//// GroveRotary ////
+
+GroveRotary::GroveRotary(unsigned int pin)
+{
+    mraa_init();
+    m_aio = mraa_aio_init(pin);
+    m_name = "Rotary Angle Sensor";
+}
+
+GroveRotary::~GroveRotary()
+{
+    mraa_aio_close(m_aio);
+}
+
+float GroveRotary::abs_value()
+{
+    return (float) mraa_aio_read(m_aio);
+}
+
+float GroveRotary::abs_deg()
+{
+    return GroveRotary::abs_value() * (float) m_max_angle / 1023.0;
+}
+
+float GroveRotary::abs_rad()
+{
+    return GroveRotary::abs_deg() * M_PI / 180.0;
+}
+
+float GroveRotary::rel_value()
+{
+    return GroveRotary::abs_value() - 512.0;
+}
+
+float GroveRotary::rel_deg()
+{
+    return GroveRotary::rel_value() * (float) m_max_angle / 1023.0;
+}
+
+float GroveRotary::rel_rad()
+{
+    return GroveRotary::rel_deg() * M_PI / 180.0;
+}