import serial
import time

try:
    puerto = serial.Serial('/dev/ttyAMA0', 921600, timeout=1.0)
    print("Escuchando...")
    t_end = time.time() + 2.0
    while time.time() < t_end:
        if puerto.in_waiting:
            print("Bytes:", puerto.read(puerto.in_waiting))
    print("Fin.")
except Exception as e:
    print("Error:", e)