../scripts/ntcLUTgen

..scriptsntcLUTgen.txt

#!/bin/bash

# Resistor-NTC divider network
# Res to VCC, NTC to GND

# resistor value
res=10000

# ntc value
ntc=10000

# adc voltage reference
aref=5

# ntc voltage
ntcv=5

# ntc beta
ntcbeta=3380

# ntc reference in K
ntcrt=298.15

# adc bits
adcbit=10

# LUT start and end 
start=0
end=1023
step=1

# result multiplier
resmul=10


###################
# end of settings #
###################

for i in `seq $start $step $end`
do
	value="`bc -l <<< "
		scale=20
		adcsteps=2^$adcbit
		voltage=($aref/adcsteps)*$i
		ntcres=voltage/(($ntcv-voltage)/$res)
		ntctemp=1/((1/$ntcrt)+((1/$ntcbeta)*l(ntcres/$ntc)))

		(ntctemp-273.15)*$resmul+0.5
		" | tr '\n' ' ' | sed -e 's/\..*//' -e 's/^$/0/' -e 's/^-$/0/'
		`"
	data="$data $value"
done

echo

sortdata="`tr ' ' '\n' <<< "$data" | sort -h`"
small="`egrep -m1 "[[:print:]]+" <<< "$sortdata"`"
big="`egrep "[[:print:]]+" <<< "$sortdata" | tail -n1`"

if [[ $small == *-* ]]
then
	# signed do not have any prefix
	type=""
else
	type="u"
fi

big="`sed -e 's/-//' -e 's/ /\n/' <<< "$small $big" | sort -h | tail -n1`"

if [ "type" = "u" ]
then
	if [ "$big" -le "255" ]
	then
		size="8"
	elif [ "$big" -le "65535" ]
	then
		size="16"
	elif [ "$big" -le "4294967295" ]
	then
		size="32"
	else
		echo "Possible Size error, assuming 64 bits"
		size="64"
	fi
else
	if [ "$big" -le "127" ]
	then
		size="8"
	elif [ "$big" -le "32767" ]
	then
		size="16"
	elif [ "$big" -le "2147483647" ]
	then
		size="32"
	else
	echo "Possible Size error, assuming 64 bits"
		size="64"
	fi
fi


echo "static const __flash ${type}int${size}_t lookup[`wc -w <<< "$data"`] = { `sed -e 's/^ //g' -e 's/  */ /g' -e 's/ /, /g'  <<< "$data"` }"