gp2y0a: renamed from gp2y0a21yk to indicate support for the gp2y0a family

Additionally, add some error checking in the constructor, and determine
the ADC resolution and use that in the voltage calculation rather than
a hardcoded 1024.0.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Zion Orent <zorent@ics.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

examples/c++/gp2y0a.cxx

@@ -0,0 +1,73 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2014 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 <unistd.h>
+#include <iostream>
+#include <signal.h>
+#include "gp2y0a.h"
+
+using namespace std;
+
+bool shouldRun = true;
+
+// analog voltage, usually 3.3 or 5.0
+#define GP2Y0A_AREF   5.0
+#define SAMPLES_PER_QUERY 20
+
+void sig_handler(int signo)
+{
+  if (signo == SIGINT)
+    shouldRun = false;
+}
+
+int main()
+{
+  signal(SIGINT, sig_handler);
+
+//! [Interesting]
+  // Note, for the Grove 80cm version of this sensor, due to the way
+  // it is wired, you need to plug this into the A0 port, where it
+  // will use the available A1 pin for data.
+
+  // Instantiate a GP2Y0A on analog pin A1
+  upm::GP2Y0A *volts = new upm::GP2Y0A(1);
+  
+  // The higher the voltage (closer to AREF) the closer the object is.  NOTE:
+  // the measured voltage will probably not exceed 3.3 volts.
+  // Every second, print the averaged voltage value (averaged over 20 samples).
+  while (shouldRun)
+    {
+      cout << "AREF: " << GP2Y0A_AREF 
+           << ", Voltage value (higher means closer): " 
+           << volts->value(GP2Y0A_AREF, SAMPLES_PER_QUERY) << endl;
+      
+      sleep(1);
+    }
+//! [Interesting]
+
+  cout << "Exiting" << endl;
+
+  delete volts;
+  return 0;
+}