为啥这个程序不能重复扫二维码分别控制舵机转？而且识别完二维码后控制的舵机一直转不会停，怎样让它转完就停？

# Untitled - By: 15839 - 周三 5月 10 2023

from pyb import Servo
import sensor, image, time

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False) # must turn this off to prevent image washout...
clock = time.clock()

s1 = Servo(1)
s2 = Servo(2)

while(True):
    clock.tick()
    img = sensor.snapshot()
    img.lens_corr(1.8) # strength of 1.8 is good for the 2.8mm lens.
    for code in img.find_qrcodes():
        img.draw_rectangle(code.rect(), color = (255, 0, 0))
        print(code.payload())
        if code.payload()=="1":
           for i in range(-90,90):
               time.sleep(2)
               s1.angle(i)
               time.sleep(2)
               s1.angle(-i)
    
        if code.payload()=="2":
           for i in range(-90,90):
               time.sleep(2)
               s2.angle(i)
               time.sleep(2)
               s2.angle(-i)