# -*- coding: utf-8 -*-
import numpy as np


'''
B is not a strictly constant alway the time
Generally we define B constant as an ratio at 298.15K and 323.15K


    \ ln(R1) - ln(R2) /
B = -------------------
        /  1    1 \
        | -- - -- |
        \ T1   T2 /
'''
# specification of NTC
B = 3434
T0 = 273.15   # zero degree
r0 = 30       # resistence when zero deree


# how big should be the look up table
r1_begin = 0.01    # -20 C
r1_end   = r0 * 3  # 125 C
r1_step  = 0.5

# write to header file
with open("Ntc_LUT.h", "a") as f:
    print('/* LookUpTable below are auto-generated!!! */', file=f)
    written = 0
    for r1 in np.arange(r1_begin, r1_end, r1_step):
        T1 = B / (B/T0-(np.log(r0)-np.log(r1)))
        if written % 8 == 7:
            print (int(T1), file=f)
        else:
            print (int(T1), end='', file=f)
            print (',', end='', file=f)
        written += 1