encoder.py

import RPi.GPIO as GPIO
import time
import math

GPIO.setmode(GPIO.BCM)
print(GPIO.VERSION)

class Encoder:

    def __init__(self, name, encoder_pin: int):
        # Initialize some stuff
        global pulse_count, start_time, time_passed, old_time_passed, old_pulse_count
        self.name = name
        self.encoder_pin = encoder_pin
        pulse_count = 0
        start_time = time.time()
        time_passed = 0
        old_time_passed = 0
        old_pulse_count = 0

        GPIO.setup(self.encoder_pin, GPIO.IN, GPIO.PUD_DOWN)

    def callback_encoder(self, channel):
        # Interrupt handler, increases pulse_count and updates time
        global pulse_count, start_time, time_passed
        time_passed = time.time() - start_time
        pulse_count += 1

    def get_pulse_count(self) -> int:
        # return pulse_count
        global pulse_count
        return pulse_count

    def reset_pulse_count(self):
        # reset pulse_count
        global pulse_count
        pulse_count = 0

    def reset_time(self):
        # reset time_passed and start_time
        global time_passed, start_time
        time_passed = 0
        start_time = time.time()

    def get_current_pulse_speed(self) -> float:
        # Get average speed since last call in pulses/s
        global pulse_count, time_passed, old_time_passed, old_pulse_count
        if (time_passed - old_time_passed):
            speed = (pulse_count - old_pulse_count) / (time_passed - old_time_passed)
        else:
            speed = 0
        old_pulse_count = pulse_count
        old_time_passed = time_passed
        return speed

    def get_speed(self) -> float:
        # Convert pulse speed to cm/s
        pulse_per_second = self.get_current_pulse_speed()
        return pulse_per_second * (6 * 2 * math.pi) / 40

    def init_callback(self):
        # Initialize the interrupt
        GPIO.add_event_detect(self.encoder_pin, GPIO.BOTH, callback=self.callback_encoder, bouncetime=10)

# try:
#     encoder1 = Encoder(name="encoder1", encoder_pin=4)
#     encoder1.init_callback()
#     while True:
#         print(encoder1.get_pulse_count())
#         print(encoder1.get_speed())
#         time.sleep(1)
# except KeyboardInterrupt:  # Exit by pressing CTRL + C
#     GPIO.cleanup()
#     print("Measurement stopped by User")
# finally:
#     GPIO.cleanup()