adxrs610: Initial implementation

This module was developed and tested on a ADXRS610 Gyro Beakout
board.

http://www.dfrobot.com/index.php?route=product/product&product_id=642

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Abhishek Malik <abhishek.malik@intel.com>

src/adxrs610/adxrs610.cxx

@@ -0,0 +1,99 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2015 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 "adxrs610.h"
+
+using namespace std;
+using namespace upm;
+
+ADXRS610::ADXRS610(int dPin, int tPin, float aref) :
+  m_aioData(dPin), m_aioTemp(tPin)
+{
+  // ADC resolution of data and temp should be the same...
+  m_aRes = (1 << m_aioData.getBit());
+  m_aref = aref;
+
+  setZeroPoint(calibrateZeroPoint());
+  setDeadband(0.0);
+
+  m_centerVolts = aref / 2.0;
+
+}
+
+ADXRS610::~ADXRS610()
+{
+}
+
+float ADXRS610::getDataVolts()
+{
+  int val = m_aioData.read();
+
+  return(float(val) * (m_aref / float(m_aRes)));
+}
+
+float ADXRS610::getTemperatureVolts()
+{
+  int val = m_aioTemp.read();
+
+  return(float(val) * (m_aref / float(m_aRes)));
+}
+
+float ADXRS610::calibrateZeroPoint(unsigned int samples)
+{
+  // The gyro should be in a stable, non-moving state
+
+  float sum = 0;
+  for (int i=0; i<samples; i++)
+    sum += getDataVolts();
+
+  return sum / samples;
+}
+
+float ADXRS610::getTemperature()
+{
+  float tempV = getTemperatureVolts();
+  
+  // nominal 2.5 volts at 25C
+  if (tempV > m_centerVolts)
+    return (m_temperatureNom + ((tempV - m_centerVolts) / m_temperatureCoeff));
+  else
+    return (m_temperatureNom - ((m_centerVolts - tempV) / m_temperatureCoeff));
+}
+
+float ADXRS610::getAngularVelocity()
+{
+  float dataV = getDataVolts();
+
+  // check the deadband
+  if (dataV < (m_zeroPoint + m_deadband) &&
+      dataV > (m_zeroPoint - m_deadband))
+    return 0.0;
+  
+  if (dataV > m_zeroPoint)
+    return ((dataV - m_zeroPoint) / m_degreeCoeff);
+  else
+    return -((m_zeroPoint - dataV) / m_degreeCoeff);
+}