1#!/usr/bin/python
2# Author: Zion Orent <zorent@ics.com>
3# Copyright (c) 2015 Intel Corporation.
4#
5# Permission is hereby granted, free of charge, to any person obtaining
6# a copy of this software and associated documentation files (the
7# "Software"), to deal in the Software without restriction, including
8# without limitation the rights to use, copy, modify, merge, publish,
9# distribute, sublicense, and/or sell copies of the Software, and to
10# permit persons to whom the Software is furnished to do so, subject to
11# the following conditions:
12#
13# The above copyright notice and this permission notice shall be
14# included in all copies or substantial portions of the Software.
15#
16# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23
24import time, sys, signal, atexit
25import pyupm_gas as upmGas
26
27# Attach gas sensor to AIO0
28myMQ9 = upmGas.MQ9(0)
29
30
31## Exit handlers ##
32# This function stops python from printing a stacktrace when you hit control-C
33def SIGINTHandler(signum, frame):
34	raise SystemExit
35
36# This function lets you run code on exit, including functions from myMQ9
37def exitHandler():
38	print "Exiting"
39	sys.exit(0)
40
41# Register exit handlers
42atexit.register(exitHandler)
43signal.signal(signal.SIGINT, SIGINTHandler)
44
45
46threshContext = upmGas.thresholdContext()
47threshContext.averageReading = 0
48threshContext.runningAverage = 0
49threshContext.averagedOver = 2
50
51# Infinite loop, ends when script is cancelled
52# Repeatedly, take a sample every 2 microseconds;
53# find the average of 128 samples; and
54# print a running graph of dots as averages
55mybuffer = upmGas.uint16Array(128)
56while(1):
57	samplelen = myMQ9.getSampledWindow(2, 128, mybuffer)
58	if samplelen:
59		thresh = myMQ9.findThreshold(threshContext, 30, mybuffer, samplelen)
60		myMQ9.printGraph(threshContext, 5)
61		if(thresh):
62			print "Threshold is ", thresh
63