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| author | hoekstar <hoekstar@cb376a5e-1013-0410-a455-b6b1f9ac8223> | 2007-12-18 23:06:28 +0000 |
|---|---|---|
| committer | hoekstar <hoekstar@cb376a5e-1013-0410-a455-b6b1f9ac8223> | 2007-12-18 23:06:28 +0000 |
| commit | 69ce5eaeb5d8bfc3c5939eb85177ecffde883dce (patch) | |
| tree | 43d0cc731046a8a6a1347726b7de702c98094b9d | |
| parent | c717df114d77852eff5338ed5fd1cbff268e57c1 (diff) | |
| download | reprap-backup-69ce5eaeb5d8bfc3c5939eb85177ecffde883dce.tar.gz reprap-backup-69ce5eaeb5d8bfc3c5939eb85177ecffde883dce.zip | |
worked on the temperature lookup script a bit.
git-svn-id: https://reprap.svn.sourceforge.net/svnroot/reprap@1192 cb376a5e-1013-0410-a455-b6b1f9ac8223
| -rw-r--r-- | trunk/users/hoeken/arduino/utilities/createTemperatureLookup.py | 148 |
1 files changed, 106 insertions, 42 deletions
diff --git a/trunk/users/hoeken/arduino/utilities/createTemperatureLookup.py b/trunk/users/hoeken/arduino/utilities/createTemperatureLookup.py index ae304fa4..2d219047 100644 --- a/trunk/users/hoeken/arduino/utilities/createTemperatureLookup.py +++ b/trunk/users/hoeken/arduino/utilities/createTemperatureLookup.py @@ -1,52 +1,116 @@ +#!/usr/bin/python +# # Creates a C code lookup table for doing ADC to temperature conversion # on a microcontroller # based on: http://hydraraptor.blogspot.com/2007/10/measuring-temperature-easy-way.html +"""Thermistor Value Lookup Table Generator + +Generates lookup to temperature values for use in a microcontroller in C format based on: +http://hydraraptor.blogspot.com/2007/10/measuring-temperature-easy-way.html + +The main use is for Arduino programs that read data from the circuit board described here: +http://make.rrrf.org/ts-1.0 + +Usage: python createTemperatureLookup.py [options] + +Options: + -h, --help show this help + --r0=... thermistor rating where # is the ohm rating of the thermistor at t0 (eg: 10K = 10000) + --t0=... thermistor temp rating where # is the temperature in Celsuis to get r0 (from your datasheet) + --beta=... thermistor beta rating. see http://reprap.org/bin/view/Main/MeasuringThermistorBeta + --r1=... R1 rating where # is the ohm rating of R1 (eg: 10K = 10000) + --r2=... R2 rating where # is the ohm rating of R2 (eg: 10K = 10000) + --num-temps=... the number of temperature points to calculate (default: 20) + --max-adc=... the max ADC reading to use. if you use R1, it limits the top value for the thermistor circuit, and thus the possible range of ADC values +""" from math import * +import sys +import getopt class Thermistor: - "Class to do the thermistor maths" - def __init__(self, r0, t0, beta, r1, r2): - self.r0 = r0 # stated resistance, e.g. 10K - self.t0 = t0 + 273.15 # temperature at stated resistance, e.g. 25C - self.beta = beta # stated beta, e.g. 3500 - self.vadc = 5.0 # ADC reference - self.vcc = 5.0 # supply voltage to potential divider - self.vs = r1 * self.vcc / (r1 + r2) # effective bias voltage - self.rs = r1 * r2 / (r1 + r2) # effective bias impedance - self.k = r0 * exp(-beta / self.t0) # constant part of calculation - - def temp(self,adc): - "Convert ADC reading into a temperature in Celcius" - v = adc * self.vadc / 1024 # convert the 10 bit ADC value to a voltage - r = self.rs * v / (self.vs - v) # resistance of thermistor - return (self.beta / log(r / self.k)) - 273.15 # temperature - - def setting(self, t): - "Convert a temperature into a ADC value" - r = self.r0 * exp(self.beta * (1 / (t + 273.15) - 1 / self.t0)) # resistance of the thermistor - v = self.vs * r / (self.rs + r) # the voltage at the potential divider - return round(v / self.vadc * 1024) # the ADC reading - -t = Thermistor(10000, 25, 3947, 1000000, 1000) - -adcs = [1, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 130, 150, 190, 220, 250, 300] -first = 1 - -print "#define NUMTEMPS ", len(adcs) - -print "short temptable[NUMTEMPS][2] = {" -print "// { adc , temp }" -for adc in adcs: - if first==1: - first = 0 - else: - print "," - print " {", adc, ", ", int(t.temp(adc)), "}", -print -print "};" + "Class to do the thermistor maths" + def __init__(self, r0, t0, beta, r1, r2): + self.r0 = r0 # stated resistance, e.g. 10K + self.t0 = t0 + 273.15 # temperature at stated resistance, e.g. 25C + self.beta = beta # stated beta, e.g. 3500 + self.vadc = 5.0 # ADC reference + self.vcc = 5.0 # supply voltage to potential divider + self.k = r0 * exp(-beta / self.t0) # constant part of calculation + + if r1 > 0: + self.vs = r1 * self.vcc / (r1 + r2) # effective bias voltage + self.rs = r1 * r2 / (r1 + r2) # effective bias impedance + else: + self.vs = self.vcc # effective bias voltage + self.rs = r2 # effective bias impedance + + def temp(self,adc): + "Convert ADC reading into a temperature in Celcius" + v = adc * self.vadc / 1024 # convert the 10 bit ADC value to a voltage + r = self.rs * v / (self.vs - v) # resistance of thermistor + return (self.beta / log(r / self.k)) - 273.15 # temperature + + def setting(self, t): + "Convert a temperature into a ADC value" + r = self.r0 * exp(self.beta * (1 / (t + 273.15) - 1 / self.t0)) # resistance of the thermistor + v = self.vs * r / (self.rs + r) # the voltage at the potential divider + return round(v / self.vadc * 1024) # the ADC reading + +def main(argv): + + r0 = 10000; + t0 = 25; + beta = 3947; + r1 = 680; + r2 = 1600; + num_temps = int(20); + max_adc = int(1023); + try: + opts, args = getopt.getopt(argv, "h", ["help", "r0=", "t0=", "beta=", "r1=", "r2="]) + except getopt.GetoptError: + usage() + sys.exit(2) + + for opt, arg in opts: + if opt in ("-h", "--help"): + usage() + sys.exit() + elif opt == "--r0": + r0 = int(arg) + elif opt == "--t0": + t0 = int(arg) + elif opt == "--beta": + beta = int(arg) + elif opt == "--r1": + r1 = int(arg) + elif opt == "--r2": + r2 = int(arg) + + increment = int(max_adc/(num_temps-1)); + t = Thermistor(r0, t0, beta, r1, r2) + + adcs = range(1, max_adc, increment); +# adcs = [1, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 130, 150, 190, 220, 250, 300] + first = 1 + + print "#define NUMTEMPS ", len(adcs) + + print "short temptable[NUMTEMPS][2] = {" + print "// { adc , temp }" + for adc in adcs: + if first==1: + first = 0 + else: + print "," + print " {", adc, ", ", int(t.temp(adc)), "}", + print + print "};" -#print t.setting(250) -#print t.temp(200) +def usage(): + print __doc__ + +if __name__ == "__main__": + main(sys.argv[1:])
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