GuyCarver-MicroPython/lib/bts7960.py

64 wiersze
1.7 KiB
Python

#Driver for the bts7960 43A high power motor controller.
from machine import Pin, PWM
from utime import sleep_ms
class motor( ):
"""Control a motor connected to the bts7960 motor controller."""
def __init__( self, aForward, aBackward, aFreq = 100 ) :
"""aForward = tuple (On Pin #, PWM Pin #)
aBackward = tuple (On Pin #, PWM Pin #)
aFreq = max frequency.
#Example:
m1 = motor((19, 22), (21, 23))
"""
self._onf = Pin(aForward[0], Pin.OUT)
self._forward = PWM(Pin(aForward[1], Pin.OUT))
self._onb = Pin(aBackward[0], Pin.OUT)
self._backward = PWM(Pin(aBackward[1], Pin.OUT))
self._maxfreq = aFreq
self._speed = 0
@staticmethod
def seton( aPin, aOn ) :
'''Set on/off (free wheeling) state of motor.'''
aPin.value(1 if aOn else 0)
@property
def speed( self ) : return self._speed
@speed.setter
def speed( self, aValue ) :
'''Set velocity and direction of motor with -100 <= aValue <= 100.'''
self._speed = aValue
pos = True
if aValue == 0 :
motor.seton(self._onb, False)
motor.seton(self._onf, False)
return
elif aValue < 0 :
aValue = -aValue
pos = False
f = self.p2hz(min(100, aValue))
motor.seton(self._onf, pos)
motor.seton(self._onb, not pos)
self._forward.freq(f)
self._backward.freq(f)
def p2hz( self, aPerc ) :
return int((self._maxfreq * aPerc) // 100)
def brake( self ) :
""" Brake the motor by sending power both directions, then shut it all down. """
self._forward.freq(self.p2hz(100))
self._backward.freq(self.p2hz(100))
motor.seton(self._onf, True)
motor.seton(self._onb, True)
sleep_ms(500)
self.speed = 0