dfrorp: Initial implementation

This module implements support for the DFRobot Analog ORP
(Oxidation/Reduction Potential) Meter.

It requires 5.0 volts, but the more accurate the voltage specified (to
the constructor), the more accurate the meter (paraphrased from the
wiki).

Signed-off-by: Jon Trulson <jtrulson@ics.com>

src/dfrorp/dfrorp.cxx

@@ -0,0 +1,86 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.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 <iostream>
+#include <stdexcept>
+
+#include "dfrorp.hpp"
+
+using namespace upm;
+using namespace std;
+
+DFRORP::DFRORP(int apin, float a_ref) :
+  m_dfrorp(dfrorp_init(apin, a_ref))
+{
+  if (!m_dfrorp)
+    throw std::runtime_error(string(__FUNCTION__)
+                             + ": dfrorp_init() failed");
+}
+
+DFRORP::~DFRORP()
+{
+  dfrorp_close(m_dfrorp);
+}
+
+void DFRORP::update()
+{
+  upm_result_t rv;
+
+  if ((rv = dfrorp_update(m_dfrorp)))
+    {
+      throw std::runtime_error(string(__FUNCTION__)
+                               + ": dfrorp_update() failed with UPM error "
+                               + std::to_string(int(rv)) );
+    }
+}
+
+void DFRORP::setOffset(float offset)
+{
+  dfrorp_set_offset(m_dfrorp, offset);
+}
+
+void DFRORP::setScale(float scale)
+{
+  dfrorp_set_scale(m_dfrorp, scale);
+}
+
+void DFRORP::setCalibrationOffset(float offset)
+{
+  dfrorp_set_calibration_offset(m_dfrorp, offset);
+}
+
+float DFRORP::getORP()
+{
+  return dfrorp_get_orp(m_dfrorp);
+}
+
+float DFRORP::getVolts()
+{
+  return dfrorp_get_volts(m_dfrorp);
+}
+
+float DFRORP::getNormalized()
+{
+  return dfrorp_get_normalized(m_dfrorp);
+}