cwlsxxa: Initial implementation

The driver was developed using the Veris CWLSHTA CO2 Gas sensor.  The
'T' variant supports a temperature sensor, and the 'H' variant
supports a humidity sensor.

All 3 signals are provided by the device as analog 0-5Vdc, 0-10Vdc, or
4-20ma loop current outputs.  For devices supporting temperature, the
valid temperature range is 10C to 50C.  The humidity ranges from 0% to
100% (non-condensing).  The CO2 sensor ranges from 0 to 2000 ppm.

This driver was developed using the 5Vdc outputs and the 4-20ma
outputs.  For voltage outputs, your MCU must be configured for 5V
operation.  In addition, you must configure the sensor (via it's
configuration switches) to output 0-5VDC only.  Using any other analog
reference voltage will require the appropriate external circuitry
(such as a voltage divider) in order to interface safely with your
MCU.

In addition, the sensor can be configured for 4-20ma usage, by
specifying the correct receiver resistance (in ohms) in the
constructor.  This sensor was tested with a Cooking Hacks (Libelium)
4-channel 4-20ma Arduino interface shield.  For this interface, the
receiver resistance was specified as 165.0 ohms.

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

examples/c++/CMakeLists.txt

@@ -248,6 +248,7 @@ add_example (max44009)
 add_example (si1132)
 add_example (si7005)
 add_example (t6713)
+add_example (cwlsxxa)
 
 # These are special cases where you specify example binary, source file and module(s)
 include_directories (${PROJECT_SOURCE_DIR}/src)

examples/c++/cwlsxxa.cxx

@@ -0,0 +1,82 @@
+/*
+ * 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 <unistd.h>
+#include <iostream>
+#include <signal.h>
+
+#include "cwlsxxa.h"
+
+using namespace std;
+
+bool shouldRun = true;
+
+void sig_handler(int signo)
+{
+  if (signo == SIGINT)
+    shouldRun = false;
+}
+
+int main(int argc, char **argv)
+{
+  signal(SIGINT, sig_handler);
+
+//! [Interesting]
+
+  cout << "Initializing..." << endl;
+
+  // Instantiate an CWLSXXA instance, using A0 for CO2, A1 for
+  // humidity and A2 for temperature
+  upm::CWLSXXA *sensor = new upm::CWLSXXA(0, 1, 2);
+
+  // update and print available values every second
+  while (shouldRun)
+    {
+      // update our values from the sensor
+      sensor->update();
+
+      // we show both C and F for temperature
+      cout << "Temperature: " << sensor->getTemperature()
+           << " C / " << sensor->getTemperature(true) << " F"
+           << endl;
+
+      cout << "Humidity: " << sensor->getHumidity()
+           << " %" << endl;
+
+      cout << "CO2: " << sensor->getCO2()
+           << " ppm" << endl;
+
+      cout << endl;
+
+      sleep(1);
+    }
+
+  cout << "Exiting..." << endl;
+
+  delete sensor;
+
+//! [Interesting]
+
+  return 0;
+}

examples/java/CMakeLists.txt

@@ -105,6 +105,7 @@ add_example(Ad8232Example ad8232)
 add_example(Gp2y0aExample gp2y0a)
 add_example(Th02Example th02)
 add_example(FlexSensorExample flex)
+add_example(CWLSXXA_Example cwlsxxa)
 
 
 add_example_with_path(Jhd1313m1_lcdSample lcd/upm_i2clcd.jar)

examples/java/CWLSXXA_Example.java

@@ -0,0 +1,62 @@
+/*
+ * 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.
+ */
+
+import upm_cwlsxxa.CWLSXXA;
+
+public class CWLSXXA_Example 
+{
+    public static void main(String[] args) throws InterruptedException
+    {
+// ! [Interesting]
+
+        // Instantiate an CWLSXXA instance, using A0 for CO2, A1 for
+        // humidity and A2 for temperature
+        CWLSXXA sensor = new CWLSXXA(0, 1, 2);
+        
+        while (true)
+            {
+                // update our values from the sensor
+                sensor.update();
+
+                // we show both C and F for temperature
+                System.out.println("Temperature: " 
+                                   + sensor.getTemperature()
+                                   + " C / "
+                                   + sensor.getTemperature(true)
+                                   + " F");
+
+                System.out.println("Humidity: "
+                                   + sensor.getHumidity()
+                                   + " %");
+
+                System.out.println("CO2: "
+                                   + sensor.getCO2()
+                                   + " ppm");
+                
+                Thread.sleep(1000);
+            }
+
+// ! [Interesting]
+    }
+}

examples/javascript/cwlsxxa.js

@@ -0,0 +1,66 @@
+/*jslint node:true, vars:true, bitwise:true, unparam:true */
+/*jshint unused:true */
+
+/*
+ * 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.
+ */
+
+
+var sensorObj = require('jsupm_cwlsxxa');
+
+
+/************** Main code **************/
+
+console.log("Initializing...");
+
+// Instantiate an CWLSXXA instance, using A0 for CO2, A1 for
+// humidity and A2 for temperature
+var sensor = new sensorObj.CWLSXXA(0, 1, 2);
+
+// update and print available values every second
+setInterval(function()
+{
+    // update our values from the sensor
+    sensor.update();
+
+    // we show both C and F for temperature
+    console.log("Temperature:", sensor.getTemperature(),
+                "C /", sensor.getTemperature(true), "F");
+
+    console.log("Humidity:", sensor.getHumidity(), "%");
+
+    console.log("CO2:", sensor.getCO2(), "ppm");
+
+    console.log("");
+
+}, 1000);
+
+
+process.on('SIGINT', function()
+{
+    sensor = null;
+    sensorObj.cleanUp();
+    sensorObj = null;
+    console.log("Exiting...");
+    process.exit(0);
+});

examples/python/cwlsxxa.py

@@ -0,0 +1,61 @@
+#!/usr/bin/python
+# 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.
+
+import time, sys, signal, atexit
+import pyupm_cwlsxxa as sensorObj
+
+## Exit handlers ##
+# This function stops python from printing a stacktrace when you hit control-C
+def SIGINTHandler(signum, frame):
+	raise SystemExit
+
+# This function lets you run code on exit
+def exitHandler():
+	print "Exiting"
+	sys.exit(0)
+
+# Register exit handlers
+atexit.register(exitHandler)
+signal.signal(signal.SIGINT, SIGINTHandler)
+
+print "Initializing..."
+
+# Instantiate an CWLSXXA instance, using A0 for CO2, A1 for
+# humidity and A2 for temperature
+sensor = sensorObj.CWLSXXA(0, 1, 2)
+
+# update and print available values every second
+while (1):
+        # update our values from the sensor
+        sensor.update()
+
+        # we show both C and F for temperature
+        print "Temperature:", sensor.getTemperature(), "C /",
+        print sensor.getTemperature(True), "F"
+
+        print "Humidity:", sensor.getHumidity(), "%"
+
+        print "CO2:", sensor.getCO2(), "ppm"
+
+        print
+	time.sleep(1)

src/cwlsxxa/CMakeLists.txt

@@ -0,0 +1,5 @@
+set (libname "cwlsxxa")
+set (libdescription "upm Veris CWLSXXA CO2/Temperature/Humidity transmitter")
+set (module_src ${libname}.cxx)
+set (module_h ${libname}.h)
+upm_module_init()

src/cwlsxxa/cwlsxxa.cxx

@@ -0,0 +1,183 @@
+/*
+ * 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 "cwlsxxa.h"
+
+using namespace upm;
+using namespace std;
+
+// for current loop reads that seems a little noisy, we average over
+// several aio reads.
+static const int maxSamples = 50;
+
+// conversion from celcius to fahrenheit
+
+static float c2f(float c)
+{
+  return (c * (9.0 / 5.0) + 32.0);
+}
+
+
+CWLSXXA::CWLSXXA(int gPin, int hPin, int tPin, float rResistor, float aref) :
+  m_aioCO2(gPin), m_aioHum(0), m_aioTemp(0)
+{
+  m_hasHum = (hPin >= 0) ? true : false;
+  m_hasTemp = (tPin >= 0) ? true : false;
+
+  if (m_hasTemp)
+    {
+      m_aioTemp = new mraa::Aio(tPin);
+      m_aResTemp = (1 << m_aioTemp->getBit());
+    }
+  else
+    m_aResTemp = 0;
+
+  if (m_hasHum)
+    {
+      m_aioHum = new mraa::Aio(hPin);
+      m_aResHum = (1 << m_aioHum->getBit());
+    }
+  else
+    m_aResHum = 0;
+
+  m_aResCO2 = (1 << m_aioCO2.getBit());
+
+  m_temperature = 0.0;
+  m_humidity = 0.0;
+  m_co2 = 0.0;
+
+  m_aref = aref;
+  m_rResistor = rResistor;
+}
+
+CWLSXXA::~CWLSXXA()
+{
+  if (m_aioHum)
+    delete m_aioHum;
+  if (m_aioTemp)
+    delete m_aioTemp;
+}
+
+void CWLSXXA::update()
+{
+  // temperature
+  int val;
+  float volts;
+  float milliamps = 0.0;
+
+  int samples;
+  if (m_rResistor)
+    samples = maxSamples;
+  else
+    samples = 1;
+
+
+  // temperature
+  if (m_hasTemp)
+    {
+      // fortunately, this sensor always reports temperatures in C,
+      // regardless of the configuration of the LCD display (for
+      // models that have an LCD display)
+
+      val = average(m_aioTemp, samples);
+
+      volts = (float(val) * (m_aref / m_aResTemp));
+
+      // valid range is 10-35C, current loop range is 16ma (20ma - 4ma)
+      if (!m_rResistor)
+        m_temperature = ((volts / m_aref) * 25.0) + 10.0;
+      else
+        {
+          milliamps = ((volts / m_rResistor * 1000.0) - 4.0);
+          if (milliamps < 0.0) // not connected
+            milliamps = 0.0;
+          m_temperature = (milliamps * (25.0 / 16.0)) + 10.0;
+        }
+    }
+
+  // humidity
+  if (m_hasHum)
+    {
+      val = average(m_aioHum, samples);
+      volts = (float(val) * (m_aref / m_aResHum));
+
+      // range is 0-100
+      if (!m_rResistor)
+        m_humidity = ((volts / m_aref) * 100.0);
+      else
+        {
+          milliamps = ((volts / m_rResistor * 1000.0) - 4.0);
+          if (milliamps < 0.0) // not connected
+            milliamps = 0.0;
+          m_humidity = milliamps * (100.0 / 16.0);
+        }
+    }
+
+  // CO2
+  val = average(&m_aioCO2, samples);
+  volts = (float(val) * (m_aref / m_aResCO2));
+  
+  // CO2 range is 0-2000ppm
+  if (!m_rResistor)
+    m_co2 = ((volts / m_aref) * 2000.0);
+  else
+    {
+      milliamps = ((volts / m_rResistor * 1000.0) - 4.0);
+      if (milliamps < 0.0) // not connected
+        milliamps = 0.0;
+      m_co2 = milliamps * (2000.0 / 16.0);
+    }
+}
+
+float CWLSXXA::getTemperature(bool fahrenheit)
+{
+  if (fahrenheit)
+    return c2f(m_temperature);
+  else
+    return m_temperature;
+}
+
+float CWLSXXA::getHumidity()
+{
+  return m_humidity;
+}
+
+float CWLSXXA::getCO2()
+{
+  return m_co2;
+}
+
+int CWLSXXA::average(mraa::Aio *aio, int samples)
+{
+  if (samples <= 0)
+    samples = 1;
+
+  int avg = 0;
+  for (int i=0; i<samples; i++)
+    avg += aio->read();
+
+  return (avg / samples);
+}

src/cwlsxxa/cwlsxxa.h

@@ -0,0 +1,189 @@
+/*
+ * 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.
+ */
+#pragma once
+
+#include <string>
+#include <iostream>
+
+#include <mraa/aio.hpp>
+
+// Unlikey to be changable without external circuitry (voltage divider)
+#define CWLSXXA_DEFAULT_AREF 5.0
+
+namespace upm {
+    /**
+     * @brief Veris CWLSXXA CO2 Sensor
+     * @defgroup cwlsxxa libupm-cwlsxxa
+     * @ingroup veris ainput temp gaseous
+     */
+
+    /**
+     * @library cwlsxxa
+     * @sensor cwlsxxa
+     * @comname Veris CWLSXXA CO2 Sensor Family
+     * @type temp gaseous
+     * @man veris
+     * @con ainput
+     * @web http://www.veris.com/Item/CWLSHTA.aspx
+     *
+     * @brief API for the Veris CWLSXXA CO2 Sensor Family
+     *
+     * The driver was developed using the CWLSHTA CO2 Gas sensor.  The
+     * 'T' variant supports a temperature transmitter, and the 'H'
+     * variant supports a humidity sensor.  All 3 signals are provided
+     * by the device as analog 0-5Vdc, 0-10Vdc, or 4-20ma loop current
+     * outputs.  For devices supporting temperature, the valid
+     * temperature range is 10C to 50C.  The humidity ranges from 0%
+     * to 100% (non-condensing).  The CO2 sensor ranges from 0 to 2000
+     * ppm.
+     *
+     * This driver was developed using the 5Vdc outputs and the 4-20ma
+     * outputs.  For voltage outputs, your MCU must be configured for
+     * 5V operation.  In addition, you must configure the sensor (via
+     * it's configuration switches) to output 0-5VDC only.  Using any
+     * other analog reference voltage will require the appropriate
+     * external circuitry (such as a voltage divider) in order to
+     * interface safely with your MCU.
+     *
+     * In addition, the sensor can be configured for 4-20ma usage, by
+     * specifying the correct receiver resistance (in ohms) in the
+     * constructor.  This sensor was tested with a Cooking Hacks
+     * (Libelium) 4-channel 4-20ma Arduino interface shield.  For this
+     * interface, the receiver resistance was specified as 165.0 ohms.
+     *
+     * For devices which do not support temperature, use '-1' as the
+     * temperature pin number in the object constructor.  If
+     * temperature measurement is disabled, getTemperature() will always
+     * return 0C/32F.
+     *
+     * For devices which do not support humidity, use '-1' as the
+     * temperature pin number in the object constructor.  If
+     * humidity measurement is disabled, getHumidity() will always
+     * return 0.
+     *
+     * @snippet cwlsxxa.cxx Interesting
+     */
+
+  class CWLSXXA {
+  public:
+
+    /**
+     * CWLSXXA object constructor
+     *
+     * @param gPin Analog pin to use for the CO2 measurement
+     * @param hPin Analog pin to use for the humidity measurement.  If
+     * your device does not support humidity, use -1 as the value so
+     * that humidity will not be queried and an analog pin won't be
+     * wasted.
+     * @param tPin Analog pin to use for temperature.  If your device
+     * does not support temperature, use -1 as the value so that
+     * temperature will not be queried and an analog pin won't be
+     * wasted.
+     * @param rResistor The receiver resistance in ohms, when using a
+     * 4-20ma current loop interface.  When specified, this value will
+     * be used in computing the current based on the voltage read when
+     * scaling the return values.  Default is 0.0, for standard
+     * scaling based on voltage output rather than current (4-20ma
+     * mode).
+     * @param aref The analog reference voltage, default 5.0
+     */
+    CWLSXXA(int gPin, int hPin, int tPin, float rResistor=0.0,
+            float aref=CWLSXXA_DEFAULT_AREF);
+
+    /**
+     * CWLSXXA object destructor
+     */
+    ~CWLSXXA();
+
+    /**
+     * Read current values from the sensor and update internal stored
+     * values.  This method must be called prior to querying any
+     * values, such as CO2, temperature, or humidity.
+     */
+    void update();
+
+    /**
+     * Get the current temperature.  update() must have been called
+     * prior to calling this method.  If temperature measurement was
+     * disabled (by passing -1 as the temperature pin in the
+     * constructor) then this function will always return 0C/32F.
+     *
+     * @param fahrenheit true to return the temperature in degrees
+     * fahrenheit, false to return the temperature in degrees celcius.
+     * The default is false (degrees Celcius).
+     * @return The last temperature reading in Celcius or Fahrenheit
+     */
+    float getTemperature(bool fahrenheit=false);
+
+    /**
+     * Get the current relative humidity.  update() must have been called
+     * prior to calling this method. If humidity measurement was
+     * disabled (by passing -1 as the te pin in the
+     * constructor) then this function will always return 0.
+     *
+     * @return The last humidity reading
+     */
+    float getHumidity();
+
+    /**
+     * Get the current CO2 concentration in Parts Per Million (PPM).
+     * update() must have been called prior to calling this method.
+     *
+     * @return The last CO2 reading
+     */
+    float getCO2();
+
+
+  protected:
+    // temperature and humidity are optional features of this transmitter
+    mraa::Aio *m_aioTemp;
+    mraa::Aio *m_aioHum;
+
+    // CO2 reporting is always supported
+    mraa::Aio m_aioCO2;
+
+  private:
+    float m_aref;
+    float m_rResistor;
+    int m_aResTemp;
+    int m_aResHum;
+    int m_aResCO2;
+
+    // does this sensor support temperature and/or humidity reporting?
+    bool m_hasTemp;
+    bool m_hasHum;
+
+    // in Celcius
+    float m_temperature;
+
+    float m_humidity;
+
+    // in PPM
+    float m_co2;
+
+    int average(mraa::Aio *aio, int samples);
+  };
+}
+
+

src/cwlsxxa/javaupm_cwlsxxa.i

@@ -0,0 +1,19 @@
+%module javaupm_cwlsxxa
+%include "../upm.i"
+%include "std_string.i"
+
+%include "cwlsxxa.h"
+%{
+    #include "cwlsxxa.h"
+%}
+
+%pragma(java) jniclasscode=%{
+    static {
+        try {
+            System.loadLibrary("javaupm_cwlsxxa");
+        } catch (UnsatisfiedLinkError e) {
+            System.err.println("Native code library failed to load. \n" + e);
+            System.exit(1);
+        }
+    }
+%}

src/cwlsxxa/jsupm_cwlsxxa.i

@@ -0,0 +1,10 @@
+%module jsupm_cwlsxxa
+%include "../upm.i"
+%include "std_string.i"
+
+%{
+    #include "cwlsxxa.h"
+%}
+
+%include "cwlsxxa.h"
+

src/cwlsxxa/pyupm_cwlsxxa.i

@@ -0,0 +1,13 @@
+// Include doxygen-generated documentation
+%include "pyupm_doxy2swig.i"
+%module pyupm_cwlsxxa
+%include "../upm.i"
+%include "std_string.i"
+
+%feature("autodoc", "3");
+
+%{
+    #include "cwlsxxa.h"
+%}
+%include "cwlsxxa.h"
+