图像识别几秒之后灯会变成红色，然后就锁定啦？

[qsmr_1752820847]

OpenMV IDE 4.7.0，固件版本 4.6.20OpenMVr2
代码：# Hello World Example

Welcome to the OpenMV IDE! Click on the green run arrow button below to run the script!

import sensor
import time
from machine import UART, LED

sensor.reset() # Reset and initialize the sensor.
sensor.set_pixformat(sensor.RGB565) # Set pixel format to RGB565 (or GRAYSCALE)
sensor.set_framesize(sensor.QVGA) # Set frame size to QVGA (320x240)
sensor.skip_frames(time=2000) # Wait for settings take effect.
clock = time.clock() # Create a clock object to track the FPS.

black = (32, 100, -128, 127, -128, 127)
uart = UART(1, 9600)

LED("LED_RED").on()

while uart.any()==0:
continue

LED("LED_BLUE").on()
LED("LED_GREEN").on()

while True:
img = sensor.snapshot() # Take a picture and return the image.
blobs = img.find_blobs([black], invert=True, roi = [0,100,320,48])

if len(blobs) == 1:
    img.draw_rectangle([0,100,320,48])
    img.draw_rectangle(blobs[0][0:4], color = (0, 255, 0))
    uart.write('#'+str(blobs[0].cx())+'$')
    print('#'+str(blobs[0].cx())+'$')
elif len(blobs) == 0:
    uart.write('S')
    print('S')
    LED("LED_GREEN").off()
    while True:
        continue