我使用电脑发送数据给openmv，修改颜色的阈值，串口返回值显示阈值修改成功了，但是实际上摄像头没有使用发送的阈值进行颜色识别，依旧使用的初始值，请问摄像头只是运行一次颜色识别的img.find_blobs吗？

L_min=0#87     #0
L_max=0#21    #100
A_min=0#27   #-128
A_max=0#93    #127
B_min=0#-5   #-128
B_max=0#92   #127
red_threshold   = (L_min, L_max, A_min, A_max, B_min, B_max)

def recive_data():
    global uart
    global L_max,A_min,B_max
    global L_min,A_max,B_min

    if uart.any():
        tmp_data = uart.readline().decode().strip().split(',')
        D_uart_0 = (tmp_data[0])
        D_uart_1 = (tmp_data[1])
        D_uart_d = int(tmp_data[2])
        D_uart_4 = (tmp_data[4])
        print(D_uart_0)
        print(D_uart_1)
        if D_uart_0=='L':
            if D_uart_1=='I':
                print(D_uart_d)
                L_min=D_uart_d
            else:
                D_uart_1=='X'
                print(D_uart_d)
                L_max=D_uart_d

        if D_uart_0=='A':
            if D_uart_1=='I':
                print(D_uart_d)
                A_min=D_uart_d
            else:
                D_uart_1=='X'
                print(D_uart_d)
                A_max=D_uart_d

        if D_uart_0=='B':
            if D_uart_1=='I':
                print(D_uart_d)
                B_min=D_uart_d
            else:
                D_uart_1=='X'
                print(D_uart_d)
                B_max=D_uart_d
while(True):
red_blobs  =  img.find_blobs([red_threshold])

但是我用其他的openmv却能正常运行；
报错的是：openmv4 cam h7 plus
正常的是：openmv4 cam h7

import sensor, image, time, math,lcd,pyb
from pyb import UART
import json
import ustruct

sensor.reset()
sensor.set_framesize(sensor.QVGA)
sensor.set_pixformat(sensor.RGB565)
sensor.skip_frames(time = 2000)
lcd.init()
clock = time.clock()
uart = UART(3,115200)   #定义串口3变量    P4 TX<-->PA10  P5 RX<-->PA9
uart.init(115200, bits=8, parity=None, stop=1) # init with given parameters

find_threshold = (35, 9, -5, 6, 28, 13)

def find_max(blobs): 
    blobs.sort(key=lambda x:x.pixels(),reverse=True);
    max_blob={}            
    length=len(blobs)
    if length>0:
        max_blob=blobs[0]
    return max_blob

def sending_data(cx_max,cy_max):
    global uart;
    #frame=[0x2C,18,cx%0xff,int(cx/0xff),cy%0xff,int(cy/0xff),0x5B];
    #data = bytearray(frame)
    data = ustruct.pack("<bbhhb", 
                   0x2C,                       
                   0x12,                      
                   int(cx_max), # up sample by 4    
                   int(cy_max), # up sample by 4    
                   0x5B);
    uart.write(data); 

while(True):
    clock.tick()
    lcd.display(sensor.snapshot()) 
    img = sensor.snapshot()#.lens_corr(1.3);
    #img.binary([binary_threshold], invert = 1)
    blobs = img.find_blobs([find_threshold],area_threshold=100,pixel_threshold=8000)


    if blobs:
        max_blob=find_max(blobs)
        img.draw_rectangle(max_blob.rect(),color=(0,0,255))
        img.draw_cross(max_blob.cx(), max_blob.cy(),color=(0,0,255))
        img.draw_cross(160, 120,color=(255,0,0)) # 在中心点画标记
        img.draw_line((160,120,max_blob.cx(),max_blob.cy()), color=(0,0,255));
        img.draw_circle(160, 120, 10, color = (255,0,0), thickness = 1, fill = False)

        xywh=max_blob.rect()
        print("xywh=",xywh)
        print("中心x坐标:",max_blob.cx(),"中心y坐标:",max_blob.cy())
        print("L =", 160 - max_blob.cx())
        print("H =", 120 - max_blob.cy())
        print("像素数量:",max_blob.pixels()) 
        print("\r\n")
        print(clock.fps())