Mercurial > circuitpython-spiderwing

comparison python/servos.py @ 0:cf2cd5a35d24 draft

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Initial commit
author Radomir Dopieralski <sheep-devel@sheep.art.pl>
date Mon, 15 May 2017 16:36:08 +0200
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-1:000000000000 0:cf2cd5a35d24
1 import pca9685
2 import math
3
4
5 TRIMS = [
6 0, -15, 0, # front left
7 0, 0,
8 10, -20, 0, # hind left
9 0, -10, .0, # hind right
10 0, 0,
11 0, -5, 0, # front right
12 ]
13
14
15 class Servos:
16 def __init__(self, i2c, address=0x40, freq=50, min_us=600, max_us=2400,
17 degrees=180):
18 self.period = 1000000 / freq
19 self.min_duty = self._us2duty(min_us)
20 self.max_duty = self._us2duty(max_us)
21 self.degrees = degrees
22 self.freq = freq
23 self.pca9685 = pca9685.PCA9685(i2c, address)
24 self.pca9685.freq(freq)
25
26 def _us2duty(self, value):
27 return int(4095 * value / self.period)
28
29 def position(self, index, degrees=None, radians=None, us=None, duty=None):
30 span = self.max_duty - self.min_duty
31 if degrees is not None:
32 duty = self.min_duty + span * degrees / self.degrees
33 elif radians is not None:
34 duty = self.min_duty + span * radians / math.radians(self.degrees)
35 elif us is not None:
36 duty = self._us2duty(us)
37 elif duty is not None:
38 pass
39 else:
40 return self.pca9685.duty(index)
41 duty = min(self.max_duty, max(self.min_duty, int(duty + TRIMS[index])))
42 self.pca9685.duty(index, duty)
43
44 def release(self, index):
45 self.pca9685.duty(index, 0)