kopia lustrzana https://github.com/peterhinch/micropython-samples
55 wiersze
1.9 KiB
Python
55 wiersze
1.9 KiB
Python
# encoder_timed.py
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# Copyright (c) 2016-2021 Peter Hinch
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# Released under the MIT License (MIT) - see LICENSE file
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import utime
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from machine import Pin, disable_irq, enable_irq
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class EncoderTimed:
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def __init__(self, pin_a, pin_b, scale=1):
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self.scale = scale # Optionally scale encoder rate to distance/angle
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self.tprev = 0
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self.tlast = 0
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self.forward = True
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self.pin_a = pin_a
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self.pin_b = pin_b
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self._pos = 0
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try:
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self.a_interrupt = pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback, hard=True)
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self.b_interrupt = pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback, hard=True)
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except TypeError:
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self.a_interrupt = pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback)
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self.b_interrupt = pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback)
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def x_callback(self, line):
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self.forward = self.pin_a.value() ^ self.pin_b.value()
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self._pos += 1 if self.forward else -1
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self.tprev = self.tlast
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self.tlast = utime.ticks_us()
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def y_callback(self, line):
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self.forward = self.pin_a.value() ^ self.pin_b.value() ^ 1
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self._pos += 1 if self.forward else -1
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self.tprev = self.tlast
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self.tlast = utime.ticks_us()
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def rate(self): # Return rate in signed distance/angle per second
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state = disable_irq()
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tlast = self.tlast # Cache current values
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tprev = self.tprev
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enable_irq(state)
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if utime.ticks_diff(utime.ticks_us(), tlast) > 2_000_000: # It's stopped
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result = 0.0
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else:
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result = 1000000.0/(utime.ticks_diff(tlast, tprev))
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result *= self.scale
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return result if self.forward else -result
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def position(self):
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return self._pos * self.scale
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def reset(self):
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self._pos = 0
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