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Restrict thermistor table range to 0C-500C 

We don't care about the accuracy of very cold temperatures
or unreasonably hot ones.
This commit is contained in:
Phil Hord 2016-04-13 16:45:54 -04:00 committed by Markus Hitter
parent 6542c284fb
commit b7a2d58b31
1 changed files with 10 additions and 4 deletions
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14
configtool/thermistortablefile.py
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@ -106,6 +106,7 @@ def BetaTable(ofp, params, names, settings, finalTable):
# It works like this: # It works like this:
# #
# - Calculate all (1024) ideal values. # - Calculate all (1024) ideal values.
# - Keep only the ones in the interesting range (0..500C).
# - Insert the two extremes into our sample list. # - Insert the two extremes into our sample list.
# - Calculate the linear approximation of the remaining values. # - Calculate the linear approximation of the remaining values.
# - Insert the correct value for the "most-wrong" estimation into our # - Insert the correct value for the "most-wrong" estimation into our
@ -115,11 +116,16 @@ def BetaTable(ofp, params, names, settings, finalTable):
# Calculate actual temps for all ADC values. # Calculate actual temps for all ADC values.
actual = dict([(x, thrm.temp(1.0 * x)) for x in range(1, int(hiadc + 1))]) actual = dict([(x, thrm.temp(1.0 * x)) for x in range(1, int(hiadc + 1))])
# Build a lookup table starting with the extremes. # Limit ADC range to 0C to 500C.
lookup = dict([(x, actual[x]) for x in [1, int(hiadc)]]) MIN_TEMP = 0
MAX_TEMP = 500
actual = dict([(adc, actual[adc]) for adc in actual
if actual[adc] <= MAX_TEMP and actual[adc] >= MIN_TEMP])
A = 1 # Build a lookup table starting with the extremes.
B = int(hiadc) A = min(actual)
B = max(actual)
lookup = dict([(x, actual[x]) for x in [A,B]])
error = dict({}) error = dict({})
while len(lookup) < N: while len(lookup) < N:
error.update(dict([(x, abs(actual[x] - LinearTableEstimate(lookup, x))) error.update(dict([(x, abs(actual[x] - LinearTableEstimate(lookup, x)))