Rotary: Added C source

Added C source for rotary angle sensor

    * Renamed all files from groverrotary to rotary
    * Replaced all instances of groverrotary with rotary
    * Added C source for rotary angle sensor
    * Updated all CMake files

Signed-off-by: Sisinty Sasmita Patra <sisinty.s.patra@intel.com>

src/rotary/rotary.c

@@ -0,0 +1,78 @@
+/*
+ * Author: Brendan Le Foll <brendan.le.foll@intel.com>
+ * 	   Sisinty Sasmita Patra <sisinty.s.patra@intel.com>
+ *
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "rotary.h"
+
+rotary_context rotary_init(int pin, float aRef)
+{
+    rotary_context dev = (rotary_context)malloc(sizeof(struct _rotary_context));
+
+    if(dev == NULL) return NULL;
+
+    dev->aio = mraa_aio_init(pin);
+
+    if(dev->aio == NULL){
+        free(dev);
+        return NULL;
+    }
+
+    dev->m_aRef = aRef;
+
+    // get adc bit range
+    dev->m_aRes = (1 << mraa_aio_get_bit(dev->aio));
+
+    return dev;
+}
+
+void rotary_close(rotary_context dev)
+{
+    mraa_aio_close(dev->aio);
+    free(dev);
+}
+
+upm_result_t rotary_get_value_voltage (const rotary_context dev,
+                                       float* volts)
+{
+    float val = 0.0;
+    val = mraa_aio_read(dev->aio);
+    *volts = (dev->m_aRef / dev->m_aRes) * (float)val;
+
+    return UPM_SUCCESS;
+}
+
+upm_result_t rotary_get_value_angle (rotary_context dev, float* rotval)
+{
+    float val = 0.0;
+    val = mraa_aio_read(dev->aio);
+
+    // return degrees
+    *rotval = val * (float)ROTARY_MAX_ANGLE / dev->m_aRes;
+
+    return UPM_SUCCESS;
+}