1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
|
#!/usr/bin/env python
import math
def main(args):
"""Calculates PWM levels for visually-linear steps.
"""
# Get parameters from the user
v = dict()
questions = [
(int, 'pwm_min', 6, 'Lowest visible PWM level, for moon mode:'),
(float, 'lm_min', 0.25, 'How bright is moon mode, in lumens?'),
(int, 'pwm_max', 255, 'Highest PWM level:'),
(float, 'lm_max', 1000, 'How bright is the highest level, in lumens?'),
(int, 'num_levels', 4, 'How many total levels do you want?'),
]
for typ, name, default, text in questions:
value = get_value(text, default, args)
if not value:
value = default
else:
value = typ(value)
v[name] = value
# change these values for each device:
#pwm_min = 0 # lowest visible PWM level, for moon mode
#lm_min = 10.0 # how bright is moon mode, in lumens?
#pwm_max = 255 # highest PWM level
#lm_max = 1300 # how bright is the highest level, in lumens?
#num_levels = 4 # how many total levels do you want?
# The rest should work fine without changes
visual_min = math.pow(v['lm_min'], 1.0/3)
visual_max = math.pow(v['lm_max'], 1.0/3)
step_size = (visual_max - visual_min) / (v['num_levels']-1)
modes = []
goal = visual_min
for i in range(v['num_levels']):
pwm_float = (((goal**3) / v['lm_max']) * (256-v['pwm_min'])) + v['pwm_min'] - 1
pwm = int(round(pwm_float))
pwm = max(min(pwm,v['pwm_max']),v['pwm_min'])
modes.append(pwm)
print '%i: visually %.2f (%.2f lm): %.2f/255' % (i+1, goal, goal ** 3, pwm_float)
goal += step_size
print 'PWM values:', ','.join([str(i) for i in modes])
def get_value(text, default, args):
if args:
result = args[0]
del args[0]
else:
print text, '(%s)' % (default),
result = raw_input()
result = result.strip()
return result
if __name__ == "__main__":
import sys
main(sys.argv[1:])
|
