LDT0-028: Add string based constructor for Piezo Vibration Sensor

Signed-off-by: Adelin Dobre <adelin.dobre1994@gmail.com>

src/ldt0028/ldt0028.cxx

@@ -31,7 +31,7 @@ using namespace upm;
 
 LDT0028::LDT0028(unsigned int pin) {
     // initialize analog input
-    if ( !(m_pin = mraa_aio_init(pin)) ) 
+    if ( !(m_pin = mraa_aio_init(pin)) )
       {
         throw std::invalid_argument(std::string(__FUNCTION__) +
                                     ": mraa_aio_init() failed, invalid pin?");
@@ -40,6 +40,26 @@ LDT0028::LDT0028(unsigned int pin) {
     m_name = "ldt0-028";
 }
 
+LDT0028::LDT0028(std::string initStr) : mraaIo(initStr) {
+  mraa_io_descriptor* descs = mraaIo.getMraaDescriptors();
+
+  if(!descs->aios)
+  {
+    throw std::invalid_argument(std::string(__FUNCTION__) +
+                                  ": mraa_aio_init() failed, invalid pin?");
+  }
+  else
+  {
+    if( !(m_pin = descs->aios[0]) )
+    {
+      throw std::invalid_argument(std::string(__FUNCTION__) +
+                              ": mraa_aio_init() failed, invalid pin?");
+
+    }
+  }
+  m_name = "ldt0-028";
+}
+
 LDT0028::~LDT0028() {
     // close analog input
     mraa_aio_close(m_pin);

src/ldt0028/ldt0028.hpp

@@ -25,6 +25,8 @@
 
 #include <string>
 #include <mraa/aio.h>
+#include <mraa/initio.hpp>
+#include <mraa/initio.h>
 
 namespace upm {
 
@@ -61,6 +63,13 @@ class LDT0028 {
          */
         LDT0028(unsigned int pin);
 
+        /**
+         * Instantiates LDT0-028 Sensor object based on a given string.
+         *
+         * @param initStr string containing specific information for LDT0-028 Sensor initialization.
+         */
+        LDT0028(std::string initStr);
+
         /**
          * LDT0028 destructor
          */
@@ -82,6 +91,7 @@ class LDT0028 {
 
     protected:
         std::string         m_name; //!< name of this sensor
+        mraa::MraaIo        mraaIo;
         mraa_aio_context    m_pin;  //!< AIO pin
 };