peripheral/libupm/examples/python/mhz16.py

#!/usr/bin/python
# Author: Zion Orent <zorent@ics.com>
# Copyright (c) 2015 Intel Corporation.
#
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# a copy of this software and associated documentation files (the
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# 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
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#
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# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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import time, sys, signal, atexit
import pyupm_mhz16 as upmMhz16

# Instantiate a MHZ16 serial CO2 sensor on uart 0.
# This example was tested on the Grove CO2 sensor module.
myCO2 = upmMhz16.MHZ16(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,
# including functions from myCO2
def exitHandler():
	print "Exiting"
	sys.exit(0)

# Register exit handlers
atexit.register(exitHandler)
signal.signal(signal.SIGINT, SIGINTHandler)


# make sure port is initialized properly.  9600 baud is the default.
if (not myCO2.setupTty(upmMhz16.cvar.int_B9600)):
	print "Failed to setup tty port parameters"
	sys.exit(0)

print ("Make sure that the sensor has had "
"at least 3 minutes to warm up\n"
"or you will not get valid results.\n"
"The temperature reported is not the ambient temperature,\n"
"but rather the temperature of the sensor elements.")

time.sleep(1)

while(1):
	if (not myCO2.getData()):
		print "Failed to retrieve data"
	else:
		outputStr = ("CO2 concentration: {0} PPM, "
		"Temperature (in C): {1}".format(
		myCO2.getGas(), myCO2.getTemperature()))
		print outputStr

	time.sleep(2)