ublox6: Initial implementation

jrvandr: removed unnecessary mraa_init() and mraa_deinit()

The module implements support for the ublox-6 GPS sensor.  It was
tested on a Grove GPS device.

This module simply allows data to be retrieved from the device in the
form of NMEA sentences, and provides a method to write commands to the
device for configuration purposes.

It does not attempt to parse NMEA data -- that is a project in itself.
There are libraries available on the Internet, such as tinyGPS++ that
can handle that for you.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Zion Orent <zorent@ics.com>
Signed-off-by: John Van Drasek <john.r.van.drasek@intel.com>

src/ublox6/CMakeLists.txt

@@ -0,0 +1,5 @@
+set (libname "ublox6")
+set (libdescription "upm u-blox 6 GPS UART support module")
+set (module_src ${libname}.cxx)
+set (module_h ${libname}.h)
+upm_module_init()

src/ublox6/jsupm_ublox6.i

@@ -0,0 +1,13 @@
+%module jsupm_ublox6
+%include "../upm.i"
+%include "stdint.i"
+%include "carrays.i"
+
+%{
+    #include "ublox6.h"
+    speed_t int_B9600 = B9600;
+%}
+
+%include "ublox6.h"
+speed_t int_B9600 = B9600;
+%array_class(char, charArray);

src/ublox6/pyupm_ublox6.i

@@ -0,0 +1,9 @@
+%module pyupm_ublox6
+%include "../upm.i"
+
+%feature("autodoc", "3");
+
+%include "ublox6.h"
+%{
+    #include "ublox6.h"
+%}

src/ublox6/ublox6.cxx

@@ -0,0 +1,140 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2014 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 "ublox6.h"
+
+using namespace upm;
+using namespace std;
+
+Ublox6::Ublox6(int uart, const char *tty) :
+  m_ttyFd(-1)
+{
+  mraa_init();
+
+  if ( !(m_uart = mraa_uart_init(uart)) )
+    {
+      cerr << __FUNCTION__ << ": mraa_uart_init() failed" << endl;
+      return;
+    }
+
+  // now open the tty
+  if ( (m_ttyFd = open(tty, O_RDWR)) == -1)
+    {
+      cerr << __FUNCTION__ << ": open of " << tty << " failed: " 
+           << strerror(errno) << endl;
+      return;
+    }
+}
+
+Ublox6::~Ublox6()
+{
+  if (m_ttyFd != -1)
+    close(m_ttyFd);
+}
+
+bool Ublox6::dataAvailable()
+{
+  if (m_ttyFd == -1)
+    return false;
+
+  struct timeval timeout;
+
+  // no waiting
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 0;
+
+  int nfds;  
+  fd_set readfds;
+
+  FD_ZERO(&readfds);
+
+  FD_SET(m_ttyFd, &readfds);
+  
+  if (select(m_ttyFd + 1, &readfds, NULL, NULL, &timeout) > 0)
+    return true;                // data is ready
+  else
+    return false;
+}
+
+int Ublox6::readData(char *buffer, size_t len)
+{
+  if (m_ttyFd == -1)
+    return(-1);
+
+  int rv = read(m_ttyFd, buffer, len);
+
+  if (rv < 0)
+    cerr << __FUNCTION__ << ": read failed: " << strerror(errno) << endl;
+
+  return rv;
+}
+
+int Ublox6::writeData(char * buffer, size_t len)
+{
+  if (m_ttyFd == -1)
+    return(-1);
+
+  int rv = write(m_ttyFd, buffer, len);
+
+  if (rv < 0)
+    {
+      cerr << __FUNCTION__ << ": write failed: " << strerror(errno) << endl;
+      return rv;
+    }
+
+  tcdrain(m_ttyFd);
+
+  return rv;
+}
+
+bool Ublox6::setupTty(speed_t baud)
+{
+  if (m_ttyFd == -1)
+    return(false);
+  
+  struct termios termio;
+
+  // get current modes
+  tcgetattr(m_ttyFd, &termio);
+
+  // setup for a 'raw' mode.  81N, no echo or special character
+  // handling, such as flow control.
+  cfmakeraw(&termio);
+
+  // set our baud rates
+  cfsetispeed(&termio, baud);
+  cfsetospeed(&termio, baud);
+
+  // make it so
+  int rv;
+  if ( (rv = tcsetattr(m_ttyFd, TCSAFLUSH, &termio)) < 0)
+    {
+      cerr << __FUNCTION__ << ": tcsetattr failed: " << strerror(errno) << endl;
+      return false;
+    }
+
+  return true;
+}

src/ublox6/ublox6.h

@@ -0,0 +1,117 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2014 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 <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <termios.h>
+#include <sys/time.h>
+#include <sys/select.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <mraa/uart.h>
+
+const int  UBLOX6_DEFAULT_UART = 0;
+
+namespace upm {
+
+  /**
+   * @brief C++ API for the U-BLOX 6 GPS module
+   *
+   * UPM support for the U-BLOX 6 GPS Module
+   *
+   * @ingroup grove uart
+   * @snippet ublox6.cxx Interesting
+   */
+  class Ublox6 {
+  public:
+    /**
+     * U-BLOX 6 GPS module constructor
+     *
+     * @param uart defualt uart to use (0 or 1)
+     * @param tty tty device to use
+     */
+    Ublox6(int uart, const char *tty);
+
+    /**
+     * U-BLOX 6 GPS module Destructor
+     */
+    ~Ublox6();
+
+    /**
+     * Check to see if there is data available for reading
+     *
+     * @return true if there is data available to be read
+     */
+    bool dataAvailable();
+
+    /**
+     * read any available data into a user-supplied buffer.  Note, the
+     * call will block until data is available to be read.  Use
+     * dataAvailable() to determine whether there is data available
+     * beforehand, to avoid blocking.
+     *
+     * @param buffer the buffer to hold the data read
+     * @param len the length of the buffer
+     * @return the number of bytes read
+     */
+    int readData(char *buffer, size_t len);
+
+    /**
+     * write the data in buffer to the device
+     *
+     * @param buffer the buffer to hold the data read
+     * @param len the length of the buffer
+     * @return the number of bytes written
+     */
+    int writeData(char *buffer, size_t len);
+
+    /**
+     * setup the proper tty i/o modes and the baudrate.  The default
+     * baud rate is 9600 (B9600).
+     *
+     * @param baud the desired baud rate.  
+     * @return true if successful
+     */
+    bool setupTty(speed_t baud=B9600);
+
+  protected:
+    int ttyFd() { return m_ttyFd; };
+    int setTtyFd(int fd) { m_ttyFd = fd; };
+
+  private:
+    mraa_uart_context m_uart;
+    int m_ttyFd;
+  };
+}
+
+