test_multiprocess.py

from multiprocessing import Process, Manager, Value
import time

class Motor:
    def __init__(self):
        self.ticks = Value('i', 0)

    def update(self):
        with self.ticks.get_lock():
            self.ticks.value += 1

def update_encoder(left_motor, right_motor):
    while True:
        left_motor.update()
        right_motor.update()


if __name__ == "__main__":
    with Manager() as manager:
        left_motor = Motor()
        right_motor = Motor()

        writer_process = Process(target=update_encoder, args=(left_motor, right_motor))
        writer_process.start()

    while True:
        print("Waiting for process to initialise...")
        time.sleep(1)
        # print(f"Value from writer process (Left Motor): {left_motor.ticks.value}")
        # print(f"Value from writer process (Right Motor): {right_motor.ticks.value}")
        tick_sum = 0
        old_ticks = (left_motor.ticks.value + right_motor.ticks.value) / 2
        counts = 6
        time_diff = 0.5
        for index in range(counts):
            time.sleep(time_diff)
            new_ticks = (left_motor.ticks.value + right_motor.ticks.value) / 2
            tick_sum += new_ticks - old_ticks
            old_ticks = new_ticks
            print(index)

        tick_diff_average = tick_sum / counts / time_diff
        print("Tick diff:", tick_diff_average)
        print("Safe from aliasing:", (0.9 * tick_diff_average) / 2)
        break