grovegprs: Initial implementation

This driver provides support for the Grove GPRS shield, V2:

http://www.seeedstudio.com/wiki/GPRS_Shield_V2.0

It provides a simple interface whereby a user can send and receive
commands and data from the device.  It is controlled by a standardized
set of "AT" commands.  A full description of these commands is
available here:

http://www.seeedstudio.com/wiki/images/7/72/AT_Commands_v1.11.pdf

Signed-off-by: Jon Trulson <jtrulson@ics.com>

examples/python/grovegprs.py

@@ -0,0 +1,86 @@
+#!/usr/bin/python
+# 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.
+
+import time, sys, signal, atexit
+import pyupm_grovegprs as sensorObj
+
+# Instantiate a GroveGPRS Module on UART 0
+sensor = sensorObj.GroveGPRS(0)
+
+## Exit handlers ##
+# This 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)
+
+# Set the baud rate, 19200 baud is the default.
+if (sensor.setBaudRate(19200)):
+	print "Failed to set baud rate"
+	sys.exit(0)
+
+
+usageStr = ("Usage:\n"
+"If an argument is supplied on the command line, that argument is\n"
+"sent to the module and the response is printed out.\n\n"
+"If no argument is used, then the manufacturer and the current\n"
+"saved profiles are queried and the results printed out.\n\n")
+print usageStr
+
+# simple helper function to send a command and wait for a response
+def sendCommand(sensor, cmd):
+        # commands need to be terminated with a carriage return
+        cmd += "\r";
+	sensor.writeDataStr(cmd)
+
+	# wait up to 1 second
+	if (sensor.dataAvailable(1000)):
+                print "Returned: ",
+		print sensor.readDataStr(1024)
+	else:
+		print "Timed out waiting for response"
+
+
+if (len(sys.argv) > 1):
+	print "Sending command line argument (" + sys.argv[1] + ")..."
+	sendCommand(sensor, sys.argv[1])
+else:
+        # query the module manufacturer
+        print "Querying module manufacturer (AT+CGMI)..."
+        sendCommand(sensor, "AT+CGMI");
+
+        time.sleep(1);
+
+        # query the saved profiles
+        print "Querying the saved profiles (AT&V)..."
+        sendCommand(sensor, "AT&V");
+
+        # A comprehensive list is available from the datasheet at:
+        # http://www.seeedstudio.com/wiki/images/7/72/AT_Commands_v1.11.pdf