diff --git a/examples/c++/CMakeLists.txt b/examples/c++/CMakeLists.txt
index fb239aa0..44cb56ad 100644
--- a/examples/c++/CMakeLists.txt
+++ b/examples/c++/CMakeLists.txt
@@ -232,6 +232,10 @@ if (OPENZWAVE_FOUND)
 endif()
 add_example (nlgpio16)
 add_example (ads1x15)
+if (MODBUS_FOUND)
+  include_directories(${MODBUS_INCLUDE_DIRS})
+  add_example (t3311)
+endif()
 
 # These are special cases where you specify example binary, source file and module(s)
 include_directories (${PROJECT_SOURCE_DIR}/src)
diff --git a/examples/c++/t3311.cxx b/examples/c++/t3311.cxx
new file mode 100644
index 00000000..1859dc6f
--- /dev/null
+++ b/examples/c++/t3311.cxx
@@ -0,0 +1,115 @@
+/*
+ * 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 "t3311.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]
+
+  string defaultDev = "/dev/ttyUSB0";
+
+  // if an argument was specified, use it as the device instead
+  if (argc > 1)
+    defaultDev = string(argv[1]);
+
+  cout << "Initializing..." << endl;
+
+  // Instantiate an T3311 instance, using MODBUS slave address 1, and
+  // default comm parameters (9600, 8, N, 2)
+  upm::T3311 *sensor = new upm::T3311(defaultDev, 1);
+
+  // output the serial number and firmware revision
+  cout << "Serial Number: " << sensor->getSerialNumber() << endl;
+  cout << "Firmware Revision: " << sensor->getFirmwareMajor()
+       << "." << sensor->getFirmwareMinor() << endl;
+  cout << endl;
+
+  // 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;
+
+      // this value depends on the sensor configuration -- by default
+      // it is the dew point temperature
+      cout << "Computed Value: " << sensor->getComputedValue() << endl;
+
+      // with FW revisions > 2.44, extended computed data is available
+      if (sensor->extendedDataAvailable())
+        {
+          cout << "Dew Point Temperature: " << sensor->getDewPointTemperature()
+               << " C / " << sensor->getDewPointTemperature(true) << " F"
+               << endl;
+
+          cout << "Absolute Humidity: " << sensor->getAbsoluteHumidity()
+               << " g/m3" << endl;
+
+          cout << "Specific Humidity: " << sensor->getSpecificHumidity()
+               << " g/kg" << endl;
+
+          cout << "Mixing Ratio: " << sensor->getMixingRatio()
+               << " g/kg" << endl;
+
+          cout << "Specific Enthalpy: " << sensor->getSpecificEnthalpy()
+               << " kJ/kg" << endl;
+        }
+
+      cout << endl;
+
+      sleep(1);
+    }
+
+  cout << "Exiting..." << endl;
+
+  delete sensor;
+
+//! [Interesting]
+
+  return 0;
+}
diff --git a/examples/javascript/t3311.js b/examples/javascript/t3311.js
new file mode 100644
index 00000000..e62679b8
--- /dev/null
+++ b/examples/javascript/t3311.js
@@ -0,0 +1,101 @@
+/*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_t3311');
+
+
+/************** Main code **************/
+
+var defaultDev = "/dev/ttyUSB0";
+
+// if an argument was specified, use it as the device instead
+if (process.argv.length > 2)
+{
+    defaultDev = process.argv[2];
+}
+
+console.log("Initializing...");
+
+// Instantiate an T3311 instance, using MODBUS slave address 1, and
+// default comm parameters (9600, 8, N, 2)
+var sensor = new sensorObj.T3311(defaultDev, 1);
+
+// output the serial number and firmware revision
+console.log("Serial Number:", sensor.getSerialNumber());
+console.log("Firmware Revision:", sensor.getFirmwareMajor() + "." +
+            sensor.getFirmwareMinor());
+console.log("");
+
+// 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(), "%");
+
+    // this value depends on the sensor configuration -- by default
+    // it is the dew point temperature
+    console.log("Computed Value:", sensor.getComputedValue());
+
+    // with FW revisions > 2.44, extended computed data is available
+    if (sensor.extendedDataAvailable())
+    {
+        console.log("Dew Point Temperature:", sensor.getDewPointTemperature(),
+                    "C /", sensor.getDewPointTemperature(true), "F");
+
+        console.log("Absolute Humidity:", sensor.getAbsoluteHumidity(),
+                    "g/m3");
+
+        console.log("Specific Humidity:", sensor.getSpecificHumidity(),
+                    "g/kg");
+
+        console.log("Mixing Ratio:", sensor.getMixingRatio(),
+                    "g/kg");
+
+        console.log("Specific Enthalpy:", sensor.getSpecificEnthalpy(),
+                    "kJ/kg");
+    }
+
+    console.log("");
+
+}, 1000);
+
+
+process.on('SIGINT', function()
+{
+    sensor = null;
+    sensorObj.cleanUp();
+    sensorObj = null;
+    console.log("Exiting...");
+    process.exit(0);
+});
diff --git a/examples/python/t3311.py b/examples/python/t3311.py
new file mode 100644
index 00000000..0c568df3
--- /dev/null
+++ b/examples/python/t3311.py
@@ -0,0 +1,90 @@
+#!/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_t3311 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)
+
+defaultDev = "/dev/ttyUSB0"
+
+# if an argument was specified, use it as the device instead
+if (len(sys.argv) > 1):
+        defaultDev = sys.argv[1]
+
+print "Initializing..."
+
+# Instantiate an T3311 instance, using MODBUS slave address 1, and
+# default comm parameters (9600, 8, N, 2)
+sensor = sensorObj.T3311(defaultDev, 1)
+
+# output the serial number and firmware revision
+print "Serial Number:", sensor.getSerialNumber()
+print "Firmware Revision: {0}.{1}".format(sensor.getFirmwareMajor(),
+                                          sensor.getFirmwareMinor())
+print
+
+# 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(), "%"
+
+        # this value depends on the sensor configuration -- by default
+        # it is the dew point temperature
+        print "Computed Value:", sensor.getComputedValue()
+
+        # with FW revisions > 2.44, extended computed data is available
+        if (sensor.extendedDataAvailable()):
+                print "Dew Point Temperature:", sensor.getDewPointTemperature(),
+                print "C /", sensor.getDewPointTemperature(True), "F"
+
+                print "Absolute Humidity:", sensor.getAbsoluteHumidity(), "g/m3"
+
+                print "Specific Humidity:", sensor.getSpecificHumidity(),
+                print "g/kg"
+
+                print "Mixing Ratio:", sensor.getMixingRatio(), "g/kg"
+
+                print "Specific Enthalpy:", sensor.getSpecificEnthalpy(),
+                print "kJ/kg"
+
+        print
+	time.sleep(1)
diff --git a/src/t3311/CMakeLists.txt b/src/t3311/CMakeLists.txt
new file mode 100644
index 00000000..3a4ab709
--- /dev/null
+++ b/src/t3311/CMakeLists.txt
@@ -0,0 +1,21 @@
+set (libname "t3311")
+set (libdescription "upm module for the Comet System T3311")
+set (module_src ${libname}.cxx)
+set (module_h ${libname}.h)
+
+pkg_search_module(MODBUS libmodbus)
+if (MODBUS_FOUND)
+  set (reqlibname "libmodbus")
+  include_directories(${MODBUS_INCLUDE_DIRS})
+  upm_module_init()
+  add_dependencies(${libname} ${MODBUS_LIBRARIES})
+  target_link_libraries(${libname} ${MODBUS_LIBRARIES})
+  if (BUILDSWIG)
+    if (BUILDSWIGNODE)
+      swig_link_libraries (jsupm_${libname} ${MODBUS_LIBRARIES} ${MRAA_LIBRARIES} ${NODE_LIBRARIES})
+    endif()
+    if (BUILDSWIGPYTHON)
+      swig_link_libraries (pyupm_${libname} ${MODBUS_LIBRARIES} ${PYTHON_LIBRARIES} ${MRAA_LIBRARIES})
+    endif()
+  endif()
+endif ()
diff --git a/src/t3311/javaupm_t3311.i b/src/t3311/javaupm_t3311.i
new file mode 100644
index 00000000..a383b49e
--- /dev/null
+++ b/src/t3311/javaupm_t3311.i
@@ -0,0 +1,23 @@
+%module javaupm_t3311
+%include "../upm.i"
+%include "typemaps.i"
+%include "cpointer.i"
+%include "arrays_java.i";
+%include "../java_buffer.i"
+
+%{
+    #include "t3311.h"
+%}
+
+%include "t3311.h"
+
+%pragma(java) jniclasscode=%{
+    static {
+        try {
+            System.loadLibrary("javaupm_t3311");
+        } catch (UnsatisfiedLinkError e) {
+            System.err.println("Native code library failed to load. \n" + e);
+            System.exit(1);
+        }
+    }
+%}
diff --git a/src/t3311/jsupm_t3311.i b/src/t3311/jsupm_t3311.i
new file mode 100644
index 00000000..4b07290c
--- /dev/null
+++ b/src/t3311/jsupm_t3311.i
@@ -0,0 +1,11 @@
+%module jsupm_t3311
+%include "../upm.i"
+%include "stdint.i"
+%include "cpointer.i"
+
+%pointer_functions(float, floatp);
+
+%include "t3311.h"
+%{
+    #include "t3311.h"
+%}
diff --git a/src/t3311/pyupm_t3311.i b/src/t3311/pyupm_t3311.i
new file mode 100644
index 00000000..51f706b7
--- /dev/null
+++ b/src/t3311/pyupm_t3311.i
@@ -0,0 +1,15 @@
+// Include doxygen-generated documentation
+%include "pyupm_doxy2swig.i"
+%module pyupm_t3311
+%include "../upm.i"
+%include "stdint.i"
+%include "cpointer.i"
+
+%feature("autodoc", "3");
+
+%pointer_functions(float, floatp);
+
+%include "t3311.h"
+%{
+    #include "t3311.h"
+%}
diff --git a/src/t3311/t3311.cxx b/src/t3311/t3311.cxx
new file mode 100644
index 00000000..01115566
--- /dev/null
+++ b/src/t3311/t3311.cxx
@@ -0,0 +1,309 @@
+/*
+ * 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 <stdexcept>
+#include <string>
+#include <sstream>
+#include <pthread.h>
+
+#include "t3311.h"
+
+using namespace upm;
+using namespace std;
+
+// conversion from fahrenheit to celcius and back
+
+static float f2c(float f)
+{
+  return ((f - 32.0) / (9.0 / 5.0));
+}
+
+static float c2f(float c)
+{
+  return (c * (9.0 / 5.0) + 32.0);
+}
+
+// conversion from 1-byte BCD to decimal
+static uint8_t bcd2dec(uint8_t bcd)
+{
+  return (bcd / 16 * 10) + (bcd % 16);
+}
+
+T3311::T3311(std::string device, int address, int baud, int bits, char parity,
+             int stopBits) :
+  m_mbContext(0)
+{
+  // check some of the parameters
+  if (!(bits == 7 || bits == 8))
+    {
+      throw std::out_of_range(std::string(__FUNCTION__) +
+                              ": bits must be 7 or 8");
+    }
+
+  if (!(parity == 'N' || parity == 'E' || parity == 'O'))
+    {
+      throw std::out_of_range(std::string(__FUNCTION__) +
+                              ": parity must be 'N', 'O', or 'E'");
+    }
+
+  if (!(stopBits == 1 || stopBits == 2))
+    {
+      throw std::out_of_range(std::string(__FUNCTION__) +
+                              ": stopBits must be 1 or 2");
+    }
+
+  m_temperature = 0.0;
+  m_humidity = 0.0;
+  m_computedValue = 0.0;
+  m_dewPointTemperature = 0.0;
+  m_absoluteHumidity = 0.0;
+  m_specificHumidity = 0.0;
+  m_mixingRatio = 0.0;
+  m_specificEnthalpy = 0.0;
+
+  // addresses are only 8bits wide
+  address &= 0xff;
+
+  // now, open/init the device and modbus context
+
+  if (!(m_mbContext = modbus_new_rtu(device.c_str(), baud, parity, bits,
+                                     stopBits)))
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": modbus_new_rtu() failed");
+    }
+
+  // set the slave address of the device we want to talk to
+  if (modbus_set_slave(m_mbContext, address))
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": modbus_set_slave() failed");
+    }
+
+  // set the serial mode
+  modbus_rtu_set_serial_mode(m_mbContext, MODBUS_RTU_RS232);
+
+  // now connect..
+  if (modbus_connect(m_mbContext))
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": modbus_connect() failed");
+    }
+
+  // This is a bit of a hack.  The device uses bus power, which isn't
+  // provided unless the device has been opened and accessed.  As a
+  // result, register reads will usually fail the first time the
+  // device is accessed after a power cycle.  Here, we read the
+  // temperature value (which will most likely fail), then sleep,
+  // allowing the sensor to "boot".  The datasheet says it takes at
+  // about 2 seconds to boot, we will wait for 5.
+  uint16_t tmp;
+  modbus_read_input_registers(m_mbContext, REG_TEMPERATURE, 1, &tmp);
+
+  // sleep for 5 seconds to give time for device to powerup and boot
+  sleep(5);
+
+  // turn off debugging
+  setDebug(false);
+
+  // now read the UNIT_SETTING reg to see what units we are getting
+  // our temperature data in.
+  tmp = readInputReg(REG_UNIT_SETTINGS);
+  if (tmp & 0x0001)
+    m_isCelcius = false;
+  else
+    m_isCelcius = true;
+
+  // read in the the FW_LO register (BCD encoded) and convert
+  tmp = readInputReg(REG_FW_LO);
+
+  // HI byte (major)
+  m_fwRevHi = (tmp >> 8) & 0xff;
+  m_fwRevHi = bcd2dec(m_fwRevHi);
+
+  // LO byte (minor)
+  m_fwRevLo = (tmp & 0xff);
+  m_fwRevLo = bcd2dec(m_fwRevLo);
+
+  if (m_fwRevHi >= 2 && m_fwRevLo >= 44)
+    m_isExtendedDataAvailable = true;
+  else
+    m_isExtendedDataAvailable = false;
+
+  // now get the serial number (BCD encoded 4-byte value, which we
+  // will pack into a string)
+  stringstream preformat;
+  uint8_t b;
+  // LO (but really HI)
+  tmp = readInputReg(REG_SERIAL_LO);
+  b = bcd2dec((tmp & 0xff00) >> 8);
+  preformat << int(b);
+
+  b = bcd2dec(tmp & 0x00ff);
+  preformat << int(b);
+
+  // HI (but really LO)
+  tmp = readInputReg(REG_SERIAL_HI);
+
+  b = bcd2dec((tmp & 0xff00) >> 8);
+  preformat << int(b);
+  b = bcd2dec(tmp & 0x00ff);
+  preformat << int(b);
+
+  m_serialNumber = preformat.str();
+}
+
+T3311::~T3311()
+{
+  if (m_mbContext)
+    {
+      modbus_close(m_mbContext);
+      modbus_free(m_mbContext);
+    }
+}
+
+uint16_t T3311::readInputReg(int reg)
+{
+  uint16_t val;
+
+  if (modbus_read_input_registers(m_mbContext, reg, 1, &val) <= 0)
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": modbus_read_input_registers() failed");
+    }
+
+  return val;
+}
+
+int T3311::readInputRegs(int reg, int len, uint16_t *buf)
+{
+  int rv;
+
+  if ((rv = modbus_read_input_registers(m_mbContext, reg, len, buf)) < 0)
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": modbus_read_input_registers() failed");
+    }
+
+  return rv;
+}
+
+void T3311::update()
+{
+  static const int dataLen = 9;
+  uint16_t data[dataLen];
+
+  // we read the 9 registers starting at the temperature
+  if (readInputRegs(REG_TEMPERATURE, dataLen, data) != dataLen)
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": read less than the expected 9 registers");
+    }
+
+  // temperature first, we always store as C
+  float tmpF = float((int16_t)data[0]) / 10.0;
+  if (m_isCelcius)
+    m_temperature = tmpF;
+  else
+    m_temperature = f2c(tmpF);
+
+  m_humidity = float((int16_t)data[1]) / 10.0;
+  m_computedValue = float((int16_t)data[2]) / 10.0;
+
+  // skip data[3], (pressure) as this device does not support it
+
+  // if extended info is supported, grab those too
+  if (extendedDataAvailable())
+    {
+      // we always store temps in C
+      tmpF = float((int16_t)data[4]) / 10.0;
+      if (m_isCelcius)
+        m_dewPointTemperature = tmpF;
+      else
+        m_dewPointTemperature = f2c(tmpF);
+
+      m_absoluteHumidity = float((int16_t)data[5]) / 10.0;
+      m_specificHumidity = float((int16_t)data[6]) / 10.0;
+      m_mixingRatio = float((int16_t)data[7]) / 10.0;
+      m_specificEnthalpy = float((int16_t)data[8]) / 10.0;
+    }
+}
+
+float T3311::getTemperature(bool fahrenheit)
+{
+  if (fahrenheit)
+    return c2f(m_temperature);
+  else
+    return m_temperature;
+}
+
+float T3311::getHumidity()
+{
+  return m_humidity;
+}
+
+float T3311::getComputedValue()
+{
+  return m_computedValue;
+}
+
+float T3311::getDewPointTemperature(bool fahrenheit)
+{
+  if (fahrenheit)
+    return c2f(m_dewPointTemperature);
+  else
+    return m_dewPointTemperature;
+}
+
+float T3311::getAbsoluteHumidity()
+{
+  return m_absoluteHumidity;
+}
+
+float T3311::getSpecificHumidity()
+{
+  return m_specificHumidity;
+}
+
+float T3311::getMixingRatio()
+{
+  return m_mixingRatio;
+}
+
+float T3311::getSpecificEnthalpy()
+{
+  return m_specificEnthalpy;
+}
+
+void T3311::setDebug(bool enable)
+{
+  m_debugging = enable;
+
+  if (enable)
+    modbus_set_debug(m_mbContext, 1);
+  else
+    modbus_set_debug(m_mbContext, 0);
+}
diff --git a/src/t3311/t3311.h b/src/t3311/t3311.h
new file mode 100644
index 00000000..f84dc95a
--- /dev/null
+++ b/src/t3311/t3311.h
@@ -0,0 +1,310 @@
+/*
+ * 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 <modbus/modbus.h>
+
+namespace upm {
+
+  /**
+   * @brief T3311 Temperature and Humidity Sensor
+   * @defgroup t3311 libupm-t3311
+   * @ingroup uart temp
+   */
+
+  /**
+   * @library t3311
+   * @sensor t3311
+   * @comname UPM API for the T3311 Temperature and Humidity Sensor
+   * @type temp
+   * @man comet
+   * @con uart
+   * @web http://www.cometsystem.com/products/reg-T3311
+   *
+   * @brief UPM API for the T3311 MODBUS Temperature and Humidity Sensor
+   *
+   * This module implements support for the Comet System T3311
+   * Temperature and Humidity transmitter.  It uses MODBUS over an
+   * RS232 serial port.  You must have libmodbus v3.1.2 (or greater)
+   * installed to compile and use this driver.
+   *
+   * This module was developed using libmodbus 3.1.2, and T3311
+   * Firmware revison 2.66 connected via a Prolific RS232 Serial to
+   * USB adaptor. You cannot use the built in TTL UART pins for
+   * accessing this device -- you must use a full serial RS232
+   * interface connected via USB.
+   *
+   * @snippet t3311.cxx Interesting
+   */
+
+  class T3311 {
+  public:
+
+    // MODBUS input registers
+    typedef enum {
+      REG_TEMPERATURE                       = 0x0030,
+      REG_HUMIDITY                          = 0x0031,
+
+      // This value is configured in the device itself.  By default,
+      // it represents the Dew Point Temperature.  Use the
+      // configuration utility from Comet to adjust the configuration.
+      REG_COMPUTED                          = 0x0032,
+
+      // available in devices with FW > 2.44
+      REG_DEW_POINT                         = 0x0034,
+      REG_ABS_HUMIDITY                      = 0x0035,
+      REG_SPECIFIC_HUMIDITY                 = 0x0036,
+      REG_MIXING_RATIO                      = 0x0037,
+      REG_SPECIFIC_ENTHALPY                 = 0x0038,
+
+      // 32 bit serial number.  These appear to be reversed when
+      // comparing against the TSensor config utility, so the
+      // datasheet is probably wrong.
+      REG_SERIAL_HI                         = 0x1034,
+      REG_SERIAL_LO                         = 0x1035,
+
+      // this is 'somewhat' documented (middle of page 15 in the
+      // Advantech-ADAM standard section) in the "Description of
+      // communications protocols of TXXXX series" document.  We use
+      // it to simply detect whether the device is configured for
+      // Celcius or Fahrenheit data and compensate internally.
+
+      REG_UNIT_SETTINGS                     = 0x203F,
+
+      // firmware revision, BCD byte encoded. We only care about the
+      // LO word - the HI word just contains the manufacturing date.
+      REG_FW_HI                             = 0x3000,
+      REG_FW_LO                             = 0x3001
+    } REGS_T;
+
+
+    /**
+     * T3311 constructor
+     *
+     * @param device Path to the serial device
+     * @param address The MODBUS slave address
+     * @param baud The baudrate of the device.  Default: 9600
+     * @param bits The number of bits per byte.  Default: 8
+     * @param parity The parity of the connection, 'N' for None, 'E'
+     * for Even, 'O' for Odd.  Default: 'N'
+     * @param stopBits The number of stop bits.  Default: 2
+     */
+    T3311(std::string device, int address, int baud=9600, int bits=8,
+          char parity='N', int stopBits=2);
+
+    /**
+     * T3311 Destructor
+     */
+    ~T3311();
+
+    /**
+     * Indicate whether the attached sensor supports extended Computed
+     * Data registers.  Firmware versions at, or higher than 2.44
+     * provide this data.
+     *
+     * @return true if Extended Data is available, false otherwise
+     */
+    bool extendedDataAvailable()
+    {
+      return m_isExtendedDataAvailable;
+    };
+
+    /**
+     * Read current values from the sensor and update internal stored
+     * values.  This method must be called prior to querying any
+     * values, such as temperature or humidity.
+     */
+    void update();
+
+    /**
+     * Get the current temperature.  update() must have been called
+     * prior to calling this method.
+     *
+     * @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.
+     *
+     * @return The last humidity reading
+     */
+    float getHumidity();
+
+    /**
+     * Get the current computed value.  update() must have been
+     * called prior to calling this method.  This value is configured
+     * via the configuration of the sensor using the sensors
+     * configuration utility, and can represent several different
+     * computed values.  The default value from the factory is the
+     * current Dew Point Temperature.
+     *
+     * Since the actual value configured is unknown (and unknowable)
+     * to this driver, the units represented depend on how you have
+     * configured the device. This function simply returns the value
+     * without any conversion or interpretation, other than the
+     * default scaling.
+     *
+     * @return The last Computed Value
+     */
+    float getComputedValue();
+
+    /**
+     * Get the current dew point temperature.  update() must have been
+     * called prior to calling this method.  This information is only
+     * available if the sensor supports Extended Data (ie:
+     * extendedDataAvailable() returns true).
+     *
+     * @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 dew point temperature reading in Celcius or
+     * Fahrenheit
+     */
+    float getDewPointTemperature(bool fahrenheit=false);
+
+    /**
+     * Get the current absolute humidity.  update() must have been
+     * called prior to calling this method.  This information is only
+     * available if the sensor supports Extended Data (ie:
+     * extendedDataAvailable() returns true).
+     *
+     * @return The last absolute humidity reading in g/m3 (grams per
+     * cubic meter).
+     */
+    float getAbsoluteHumidity();
+
+    /**
+     * Get the current specific humidity.  update() must have been
+     * called prior to calling this method.  This information is only
+     * available if the sensor supports Extended Data (ie:
+     * extendedDataAvailable() returns true).
+     *
+     * @return The last specific humidity reading in g/kg (grams per
+     * kilogram).
+     */
+    float getSpecificHumidity();
+
+    /**
+     * Get the current mixing ratio.  update() must have been
+     * called prior to calling this method.  This information is only
+     * available if the sensor supports Extended Data (ie:
+     * extendedDataAvailable() returns true).
+     *
+     * @return The last mixing ratio reading in g/kg (grams per
+     * kilogram).
+     */
+    float getMixingRatio();
+
+    /**
+     * Get the current specific enthalopy, a measure of energy
+     * density.  update() must have been called prior to calling this
+     * method.  This information is only available if the sensor
+     * supports Extended Data (ie: extendedDataAvailable() returns
+     * true).
+     *
+     * @return The last specific enthalopy reading in kJ/kg
+     * (kilojoules per kilogram).
+     */
+    float getSpecificEnthalpy();
+
+    /**
+     * Get the serial number of the sensor.
+     *
+     * @return The serial number
+     */
+    std::string getSerialNumber()
+    {
+      return m_serialNumber;
+    };
+
+    /**
+     * Get the firmware revision major number.
+     *
+     * @return The firmware revsion major number.
+     */
+    int getFirmwareMajor()
+    {
+      return m_fwRevHi;
+    };
+
+    /**
+     * Get the firmware revision minor number.
+     *
+     * @return The firmware revsion minor number.
+     */
+    int getFirmwareMinor()
+    {
+      return m_fwRevLo;
+    };
+
+    /**
+     * Enable or disable debugging output.  This primarily enables and
+     * disables libmodbus debugging output.
+     *
+     * @param enable true to enable debugging, false otherwise
+     */
+    void setDebug(bool enable);
+
+  protected:
+    uint16_t readInputReg(int reg);
+    int readInputRegs(int reg, int len, uint16_t *buf);
+
+    // MODBUS context
+    modbus_t *m_mbContext;
+
+    // is the device reporting in C or F?
+    bool m_isCelcius;
+
+    // Is the device FW > than 2.44?
+    bool m_isExtendedDataAvailable;
+
+    int m_fwRevHi;
+    int m_fwRevLo;
+
+    std::string m_serialNumber;
+
+  private:
+    bool m_debugging;
+
+    // data
+    float m_temperature;
+    float m_humidity; // relative
+    float m_computedValue;
+
+    // with FW versions > 2.44, these other computed values are
+    // available.
+    float m_dewPointTemperature;
+    float m_absoluteHumidity;
+    float m_specificHumidity;
+    float m_mixingRatio;
+    float m_specificEnthalpy;
+  };
+}
diff --git a/src/upm.h b/src/upm.h
index d35cbbbf..39f6d313 100644
--- a/src/upm.h
+++ b/src/upm.h
@@ -284,6 +284,12 @@
  * @ingroup byman
  */
 
+/**
+ * @brief Comet System
+ * @defgroup comet Comet
+ * @ingroup byman
+ */
+
 /**
  * @brief EpicTinker
  * @defgroup epict EpicTinker