gp2y0a: renamed from gp2y0a21yk to indicate support for the gp2y0a family

Additionally, add some error checking in the constructor, and determine
the ADC resolution and use that in the voltage calculation rather than
a hardcoded 1024.0.

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

examples/python/gp2y0a.py

@@ -0,0 +1,62 @@
+#!/usr/bin/python
+# Author: Zion Orent <zorent@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_gp2y0a as upmGp2y0a
+
+# Note, for the Grove 80cm version of this sensor, due to the way it is wired,
+# you need to plug this into the A0 port, where it will use the available
+# A1 pin for data.
+# Instantiate a GP2Y0A on analog pin A1
+myIRProximity = upmGp2y0a.GP2Y0A(1)
+
+
+## Exit handlers ##
+# This stops python from printing a stacktrace when you hit control-C
+def SIGINTHandler(signum, frame):
+	raise SystemExit
+
+# This lets you run code on exit,
+# including functions from myIRProximity
+def exitHandler():
+	print "Exiting"
+	sys.exit(0)
+
+# Register exit handlers
+atexit.register(exitHandler)
+signal.signal(signal.SIGINT, SIGINTHandler)
+
+
+# analog voltage, usually 3.3 or 5.0
+GP2Y0A_AREF = 5.0;
+SAMPLES_PER_QUERY = 20;
+
+# The higher the voltage (closer to AREF) the closer the object is.
+# NOTE: The measured voltage will probably not exceed 3.3 volts.
+# Every second, print the averaged voltage value
+# (averaged over 20 samples).
+while (1):
+	print "AREF: {0}, Voltage value (higher means closer): {1}".format(
+	GP2Y0A_AREF,
+	myIRProximity.value(GP2Y0A_AREF, SAMPLES_PER_QUERY))
+	time.sleep(1)