Create correction table for PWM values based on CIE1931 algorithm

LED_cie1931.py

#!/usr/bin/python3
#
''' Script to create a correction table for PWM values
    to create linear brightness for a LED
    based on the CIE1931 algorithm
    original author: ?? 
'''
PWM_BIT_SIZE = 8        # Bit size of used PWM
CORR_TABLE_SIZE = 16    # Number of elements in vector
####
INPUT_SIZE = CORR_TABLE_SIZE-1       # Input integer size  / max vector index
OUTPUT_SIZE = 2**PWM_BIT_SIZE-1      # Output integer size / max pwm range
#INT_TYPE = 'const unsigned char'
INT_TYPE = 'const uint8_t'

TABLE_NAME = 'cie';
 
def cie1931(L):
    L = L*100.0
    if L <= 8:
        return (L/902.3)
    else:
        return ((L+16.0)/116.0)**3

 
x = range(0,int(INPUT_SIZE+1))
y = [round(cie1931(float(L)/INPUT_SIZE)*OUTPUT_SIZE) for L in x]
 
with open('cie1931.h', 'w') as f:
    f.write('// CIE1931 correction table\n')
    f.write('// Automatically generated\n\n')
 
    f.write('%s %s[%d] = {\n' % (INT_TYPE, TABLE_NAME, INPUT_SIZE+1))
    f.write('\t')
    for i,L in enumerate(y):
        if i < len(y)-1:
            f.write('%d, ' % int(L))
            if i % 10 == 9:
                f.write('\n\t')     # linefeed after 10 elements
        else:
            f.write('%d' % int(L))    
    f.write('\n};\n\n')
 
print('Done!\n')