ADIS16448: Add string based constructor for Accelerometer

Signed-off-by: Adelin Dobre <adelin.dobre1994@gmail.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/adis16448/adis16448.hpp

@@ -39,6 +39,7 @@
 #include <string>
 #include <mraa/spi.h>
 #include <mraa/gpio.h>
+#include <mraa/initio.hpp>
 
 // User Register Memory Map from Table 6 of the Datasheet
 #define FLASH_CNT 0x00 //Flash memory write count
@@ -113,6 +114,13 @@ namespace upm {
          */
         ADIS16448(int bus, int rst);
 
+        /**
+         * Instantiates ADIS16448 Accelerometer object based on a given string.
+         *
+         * @param initStr string containing specific information for ADIS16448 initialization.
+         */
+        ADIS16448(std::string initStr);
+
         /**
          * Destructor
          */
@@ -165,6 +173,7 @@ namespace upm {
 
         private:
 
+        mraa::MraaIo mraaIo;
         mraa_spi_context _spi;
         mraa_gpio_context _rst;