rhusb: Initial implementation

The driver implements support for the Omega RH-USB Humidity Probe with
Temperature sensor.  It connects via an integrated USB cable, and
appears as a serial port.

It does not currently work with Edison (as of this date) due to
missing ftdi_sio and usbserial kernel support.

It was implemented and tested on the Galileo 2.

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

src/rhusb/CMakeLists.txt

@@ -0,0 +1,6 @@
+set (libname "rhusb")
+set (libdescription "upm module for the Omega RH-USB sensor")
+set (module_src ${libname}.cxx)
+set (module_h ${libname}.h)
+upm_module_init()
+

src/rhusb/javaupm_rhusb.i

@@ -0,0 +1,23 @@
+%module javaupm_rhusb
+%include "../upm.i"
+%include "typemaps.i"
+%include "cpointer.i"
+%include "arrays_java.i";
+%include "../java_buffer.i"
+
+%{
+    #include "rhusb.h"
+%}
+
+%include "rhusb.h"
+
+%pragma(java) jniclasscode=%{
+    static {
+        try {
+            System.loadLibrary("javaupm_rhusb");
+        } catch (UnsatisfiedLinkError e) {
+            System.err.println("Native code library failed to load. \n" + e);
+            System.exit(1);
+        }
+    }
+%}

src/rhusb/jsupm_rhusb.i

@@ -0,0 +1,8 @@
+%module jsupm_rhusb
+%include "../upm.i"
+%include "stdint.i"
+
+%include "rhusb.h"
+%{
+    #include "rhusb.h"
+%}

src/rhusb/pyupm_rhusb.i

@@ -0,0 +1,12 @@
+// Include doxygen-generated documentation
+%include "pyupm_doxy2swig.i"
+%module pyupm_rhusb
+%include "../upm.i"
+%include "stdint.i"
+
+%feature("autodoc", "3");
+
+%include "rhusb.h"
+%{
+    #include "rhusb.h"
+%}

src/rhusb/rhusb.cxx

@@ -0,0 +1,179 @@
+/*
+ * 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 <stdlib.h>
+#include <iostream>
+#include <stdexcept>
+#include <string>
+
+#include "rhusb.h"
+
+using namespace upm;
+using namespace std;
+
+static const int maxBuffer = 1024;
+// baud rate is always 9600
+static const int baudRate = 9600;
+
+// conversion from celcius to fahrenheit 
+
+static float c2f(float c)
+{
+  return (c * (9.0 / 5.0) + 32.0);
+}
+
+RHUSB::RHUSB(std::string device) :
+  m_uart(device)
+{
+  m_uart.setBaudRate(baudRate);
+
+  m_temperature = 0.0;
+  m_humidity = 0.0;
+}
+
+RHUSB::~RHUSB()
+{
+}
+
+void RHUSB::update()
+{
+  char *endptr;
+  float value;
+
+  // first get the temp in C
+  string resp = sendCommand("C");
+
+  // convert
+  value = strtof(resp.c_str(), &endptr);
+
+  // check for conversion failure
+  if (value == 0.0 && resp.c_str() == endptr)
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": strtof() temperature conversion failed");
+    }
+  m_temperature = value;
+
+  // now humidity
+  resp = sendCommand("H");
+
+  // convert
+  value = strtof(resp.c_str(), &endptr);
+
+  // check for conversion failure
+  if (value == 0.0 && resp.c_str() == endptr)
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": strtof() humidity conversion failed");
+    }
+  m_humidity = value;
+}
+
+float RHUSB::getTemperature(bool fahrenheit)
+{
+  if (fahrenheit)
+    return c2f(m_temperature);
+  else
+    return m_temperature;
+}
+
+float RHUSB::getHumidity()
+{
+  return m_humidity;
+}
+
+bool RHUSB::dataAvailable(unsigned int millis)
+{
+  return m_uart.dataAvailable(millis);
+}
+
+string RHUSB::readStr(int len)
+{
+  return m_uart.readStr(len);
+}
+
+int RHUSB::writeStr(string data)
+{
+  m_uart.flush();
+  return m_uart.writeStr(data);
+}
+
+string RHUSB::sendCommand(string cmd)
+{
+  // make sure we got a command
+  if (cmd.empty())
+    {
+      throw std::invalid_argument(std::string(__FUNCTION__) +
+                                  ": cmd is empty!");
+      return "";
+    }
+
+  // make sure string is CR terminated
+  if (cmd.at(cmd.size() - 1) != '\r')
+    cmd.append("\r");
+
+  writeStr(cmd);
+
+  string resp;
+  // I see random timeouts with wait values below 250ms
+  while (dataAvailable(250))
+    {
+      resp += readStr(maxBuffer);
+    }
+
+  if (resp.empty())
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": timed out waiting for response");
+      return "";
+    }
+
+  // check that the last character is the prompt
+  if (resp.at(resp.size() - 1) != '>')
+    {
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": read from device corrupted");
+      return "";
+    }
+
+  // delete the last 3 characters, which should be '\r\n>'
+  resp.erase(resp.size() - 3, 3);
+
+  return resp;
+}
+
+string RHUSB::getFirmwareID()
+{
+  string resp = sendCommand("ENQ");
+
+  // For readability, replace the intermediate \r\n with a space if found.
+
+  size_t pos = resp.find("\r\n");
+
+  if (pos != string::npos)
+    resp.replace(pos, 2, " ");
+
+  return resp;
+}

src/rhusb/rhusb.h

@@ -0,0 +1,118 @@
+/*
+ * 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 <mraa/uart.hpp>
+
+namespace upm {
+
+  /**
+   * @brief Omega RH-USB Temperature and Humidity Sensor
+   * @defgroup rhusb libupm-rhusb
+   * @ingroup uart temp
+   */
+
+  /**
+   * @library rhusb
+   * @sensor rhusb
+   * @comname UPM API for the Omega RH-USB Temperature and Humidity Sensor
+   * @type temp
+   * @man omega
+   * @con uart
+   * @web http://www.omega.com/pptst/RH-USB.html
+   *
+   * @brief UPM API for the Omega RH-USB Temperature and Humidity Sensor
+   *
+   * This module implements support for the Omega RH-USB Temperature
+   * and Humidity Sensor Probe.  It connects via an integrated USB
+   * cable, and is accessed via a serial port.  It is suitable for
+   * wall or duct mounting.
+   *
+   * @snippet rhusb.cxx Interesting
+   */
+
+  class RHUSB {
+  public:
+    /**
+     * RHUSB constructor
+     *
+     * @param device Path to the serial device
+     */
+    RHUSB(std::string device);
+
+    /**
+     * RHUSB Destructor
+     */
+    ~RHUSB();
+
+    /**
+     * 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 firmware identification string.
+     *
+     * @return The firmware identification
+     */
+    std::string getFirmwareID();
+
+
+  protected:
+    // serial i/o support
+    bool dataAvailable(unsigned int millis);
+    int writeStr(std::string data);
+    std::string readStr(int len);
+    std::string sendCommand(std::string cmd);
+
+    mraa::Uart m_uart;
+
+  private:
+    // data
+    float m_temperature;
+    float m_humidity;
+  };
+}