createTemperature.pyを使う
設定パラメータ
r0=100000.0 (100kΩ：２５℃でのサーミスタの抵抗値R25)
t0=25（基準温度25℃）
r1=0.0 （低温時の発熱損失を押さえるための分流抵抗→使用しない）
r2=4700.0（4.7kΩ分圧抵抗）
beta=4267（サーミスタの定数B：データシートより）
max-adc=4096（12ビットA/Dコンバータ）
#!/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 Updated by Shohei Aoki, 2017 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 --vcc=... Supply voltage Vcc which coordinates with ADC reference Vadc """ from math import * import sys import getopt class Thermistor: "Class to do the thermistor maths" def __init__(self, r0, t0, beta, r1, r2, max_adc, vcc): 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 = vcc # ADC reference self.vcc = vcc # supply voltage to potential divider self.k = r0 * exp(-beta / self.t0) # constant part of calculation self.max_adc = max_adc 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 / self.max_adc # 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 * self.max_adc) # the ADC reading def main(argv): r0 = 100000; t0 = 25; beta = 4267; r1 = 0; r2 = 4700; num_temps = int(61); vcc = 5.0 max_adc_raw = 1023 try: opts, args = getopt.getopt(argv, "h", ["help", "r0=", "t0=", "beta=", "r1=", "r2=", "max-adc=", "vcc="]) except getopt.GetoptError: usage() sys.exit(2) for opt, arg in opts: if opt in ("-h", "--help"): usage() sys.exit() elif opt == "--r0": r0 = float(arg) elif opt == "--t0": t0 = int(arg) elif opt == "--beta": beta = int(arg) elif opt == "--r1": r1 = float(arg) elif opt == "--r2": r2 = float(arg) elif opt == "--max-adc": max_adc_raw = int(arg) elif opt == "--vcc": vcc = float(arg) if r1: max_adc = int(max_adc_raw * r1 / (r1 + r2)); else: max_adc = max_adc_raw increment = int(max_adc/(num_temps-1)); t = Thermistor(r0, t0, beta, r1, r2, max_adc, vcc) adcs = list(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("// Thermistor lookup table for RepRap Temperature Sensor Boards (http://make.rrrf.org/ts)") print("// Made with createTemperatureLookup.py (http://svn.reprap.org/trunk/reprap/firmware/Arduino/utilities/createTemperatureLookup.py)") print("// ./createTemperatureLookup.py --r0=%s --t0=%s --r1=%s --r2=%s --beta=%s --max-adc=%s --vcc=%s" % (r0, t0, r1, r2, beta, max_adc, vcc)) print("// r0: %s" % (r0)) print("// t0: %s" % (t0)) print("// r1: %s" % (r1)) print("// r2: %s" % (r2)) print("// beta: %s" % (beta)) print("// max adc: %s" % (max_adc)) print("// vcc: %s" % (vcc)) print("#define NUMTEMPS %s" % (len(adcs))) print("short temptable[NUMTEMPS][2] = {") counter = 0 for adc in adcs: counter = counter +1 temp_adc = int(t.temp(adc)) if int(t.temp(adc)) > 0 else 0 if counter == len(adcs): print(" {%s, %s}" % (adc, temp_adc)) else: print(" {%s, %s}," % (adc, temp_adc)) print("};") def usage(): print(__doc__) if __name__ == "__main__": main(sys.argv[1:])
$ ./createTemperatureLookup.py --r0=100000 --t0=25 --r1=0 --r2=4700.0 --beta=4267 --max-adc=4096 --vcc=3.3
// Thermistor lookup table for RepRap Temperature Sensor Boards (http://make.rrrf.org/ts)
// Made with createTemperatureLookup.py (http://svn.reprap.org/trunk/reprap/firmware/Arduino/utilities/createTemperatureLookup.py)
// ./createTemperatureLookup.py --r0=100000.0 --t0=25 --r1=0.0 --r2=4700.0 --beta=4267 --max-adc=4096 --vcc=3.3
// r0: 100000.0
// t0: 25
// r1: 0.0
// r2: 4700.0
// beta: 4267
// max adc: 4096
// vcc: 3.3
#define NUMTEMPS 61
short temptable[NUMTEMPS][2] = {
{1, 1179},
{69, 320},
{137, 267},
{205, 240},
{273, 222},
{341, 208},
{409, 198},
{477, 189},
{545, 181},
{613, 175},
{681, 169},
{749, 164},
{817, 159},
{885, 155},
{953, 150},
{1021, 147},
{1089, 143},
{1157, 140},
{1225, 137},
{1293, 133},
{1361, 131},
{1429, 128},
{1497, 125},
{1565, 122},
{1633, 120},
{1701, 117},
{1769, 115},
{1837, 113},
{1905, 110},
{1973, 108},
{2041, 106},
{2109, 104},
{2177, 101},
{2245, 99},
{2313, 97},
{2381, 95},
{2449, 93},
{2517, 90},
{2585, 88},
{2653, 86},
{2721, 84},
{2789, 82},
{2857, 79},
{2925, 77},
{2993, 75},
{3061, 72},
{3129, 70},
{3197, 67},
{3265, 64},
{3333, 62},
{3401, 59},
{3469, 55},
{3537, 52},
{3605, 48},
{3673, 44},
{3741, 40},
{3809, 35},
{3877, 28},
{3945, 20},
{4013, 8},
{4081, 0}
};
