encoder.py

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from time import ticks_us, ticks_diff  # Use to get dt value in update()
from pyb import Pin, Timer

class Encoder:
   
    
    def __init__(self, tim, chA_pin, chB_pin):
        #Initializes an Encoder object
        self.position = 0  # Total accumulated position of the encoder
        self.prev_count = 0  # Counter value from the most recent update
        self.delta = 0  # Change in count between last two updates
        self.dt = 0  # Amount of time between last two updates
        self.last_time = 0
        self.current_time = 0
        self.tim = tim
        self.offset = 0
        self.tim.init(prescaler = 0, period = 65535)
        self.timCh_A = tim.channel(1, pin=chA_pin, mode=Timer.ENC_A)
        self.timCh_B = tim.channel(2, pin=chB_pin, mode=Timer.ENC_B)
 
    
    def update(self):
        self.delta = self.tim.counter() - self.prev_count
 
        self.current_time=ticks_us()
        self.dt = ticks_diff(self.current_time, self.last_time)
        self.last_time = ticks_us()
        
        if self.delta > 65536 / 2:
            self.delta -= 65536
        elif self.delta < -65536 / 2:
            self.delta += 65536
 
        self.prev_count = self.tim.counter()
        self.position += self.delta
        
        
    
    def get_position(self):
        return (self.position * 1/1437.1 * 2 * 3.14159 * 35) + self.offset
 
    
    def get_velocity(self):
        return (self.delta / self.dt) * 1/1437.1 *2 * 3.14159 * 35 * -1000000
 
    
    def zero(self):
        self.position = 0
        self.prev_count = self.tim.counter()
    
    
    def get_dt(self):
        return self.dt
    
    
    def set_offset(self, offset):
        self.offset = offset