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#!/usr/bin/python |
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|
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### |
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# Program to read the temperature from a DLP-TEMP-G from a Linux computer |
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# http://www.dlpdesign.com/usb/temp.shtml |
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# |
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# Loosely based on Tim Jensen's program at |
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# http://www.jensens.org/tim/read-temperature.txt |
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# |
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# Copyright (c) 2007 Andrew Pollock <me@andrew.net.au> |
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# |
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# This program is free software; you can redistribute it and/or modify |
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# it under the terms of the GNU General Public License as published by |
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# the Free Software Foundation; either version 2 of the License. |
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# |
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# This program is distributed in the hope that it will be useful, |
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# but WITHOUT ANY WARRANTY; without even the implied warranty of |
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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# GNU General Public License for more details. |
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# |
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# You should have received a copy of the GNU General Public License along |
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# with this program; if not, write to the Free Software Foundation, Inc., |
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# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
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# |
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|
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try: |
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import serial |
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except ImportError: |
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print "This program requires pyserial,", \ |
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"try checking the python-serial package is installed" |
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|
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from optparse import OptionParser |
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import sys |
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|
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def read_temperature(device, sensor): |
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ser = serial.Serial(device, 9600, timeout=1) |
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|
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ser.write(SENSOR_QUERY_CMD[sensor]) |
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buf = ser.read(8) |
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ser.close() |
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|
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temp = ord(buf[0]) | (ord(buf[1]) << 8) |
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return temp |
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|
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|
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SENSOR_QUERY_CMD = (None, 'S', 'T', 'U') |
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USAGE = "usage: %prog [options] [action]" |
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|
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parser = OptionParser(USAGE) |
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parser.add_option("-F", "--fahrenheit", action="store_false", |
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dest="use_celsius", help="Output temperature in degrees Fahrenheit", |
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default=False) |
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parser.add_option("-C", "--celsius", action="store_true", |
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dest="use_celsius", help="Output temperature in degrees Celsius", |
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default=True) |
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parser.add_option("-d", "--device", action="store", type="string", |
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dest="device", help="device to communicate with", |
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default="/dev/ttyUSB0") |
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parser.add_option("-s", "--sensor", action="store", type="int", |
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dest="sensor", help="sensor to query", |
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default="1") |
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parser.add_option("--mrtg", action="store_true", |
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dest="output_mrtg", help="Output decimal value suitable for MRTG", |
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default=False) |
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(options, args) = parser.parse_args() |
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|
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if not(options.sensor > 0 and options.sensor <= len(SENSOR_QUERY_CMD) - 1): |
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parser.error("Invalid sensor") |
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|
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try: |
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temp = read_temperature(options.device, options.sensor) |
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except serial.SerialException, e: |
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print "%s" % (e) |
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sys.exit(1) |
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|
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degrees = temp / 16.0 |
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|
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# The power-up temperature of the sensor is 85 degrees, which is fairly unlikely |
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# So if we get that temperature, try reading it again |
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|
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if degrees == 85.0: |
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try: |
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temp = read_temperature(options.device, options.sensor) |
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except serial.SerialException, e: |
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print "%s" % (e) |
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sys.exit(1) |
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degrees = temp / 16.0 |
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|
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if (options.use_celsius): |
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if (options.output_mrtg): |
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print "%.0f" % degrees |
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else: |
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print "%.4f degrees Celsius" % degrees |
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else: |
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degrees = (9.0/5.0) * degrees + 32.0 |
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if (options.output_mrtg): |
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print "%.0f" % degrees |
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else: |
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print "%.4f degrees Fahrenheit" % degrees |