kopia lustrzana https://github.com/peterhinch/micropython-samples
66 wiersze
2.3 KiB
Python
66 wiersze
2.3 KiB
Python
# encoder_timed.py
|
|
|
|
# Copyright (c) 2016-2021 Peter Hinch
|
|
# Released under the MIT License (MIT) - see LICENSE file
|
|
# Improvements provided by IhorNehrutsa
|
|
|
|
import utime
|
|
from machine import Pin, disable_irq, enable_irq
|
|
|
|
class EncoderTimed:
|
|
def __init__(self, pin_x, pin_y, scale=1):
|
|
self.scale = scale # Optionally scale encoder rate to distance/angle
|
|
self.tprev = -1
|
|
self.tlast = -1
|
|
self.forward = True
|
|
self.pin_x = pin_x
|
|
self.pin_y = pin_y
|
|
self._pos = 0
|
|
try:
|
|
self.x_interrupt = pin_x.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.x_callback, hard=True)
|
|
self.y_interrupt = pin_y.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.y_callback, hard=True)
|
|
except TypeError:
|
|
self.x_interrupt = pin_x.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.x_callback)
|
|
self.y_interrupt = pin_y.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.y_callback)
|
|
|
|
def x_callback(self, line):
|
|
self.forward = self.pin_x.value() ^ self.pin_y.value()
|
|
self._pos += 1 if self.forward else -1
|
|
self.tprev = self.tlast
|
|
self.tlast = utime.ticks_us()
|
|
|
|
def y_callback(self, line):
|
|
self.forward = self.pin_x.value() ^ self.pin_y.value() ^ 1
|
|
self._pos += 1 if self.forward else -1
|
|
self.tprev = self.tlast
|
|
self.tlast = utime.ticks_us()
|
|
|
|
def rate(self): # Return rate in signed distance/angle per second
|
|
state = disable_irq()
|
|
tlast = self.tlast # Cache current values
|
|
tprev = self.tprev
|
|
enable_irq(state)
|
|
if self.tprev == -1: # No valid times yet
|
|
return 0.0
|
|
dt = utime.ticks_diff(utime.ticks_us(), tlast)
|
|
if dt > 2_000_000: # Stopped
|
|
return 0.0
|
|
dt = utime.ticks_diff(tlast, tprev)
|
|
if dt == 0: # Could happen on future rapid hardware
|
|
return 0.0
|
|
result = self.scale * 1_000_000.0/dt
|
|
return result if self.forward else -result
|
|
|
|
def position(self, value=None):
|
|
if value is not None:
|
|
self._pos = round(value / self.scale)
|
|
return self._pos * self.scale
|
|
|
|
def reset(self):
|
|
self._pos = 0
|
|
|
|
def value(self, value=None):
|
|
if value is not None:
|
|
self._pos = value
|
|
return self._pos
|