串口有发送数据，但是用串口调试助手看是空的

我已经按照你说的修改了代码，但是还是在脱机运行的时候会卡死，无法脱机运行。

color code 定义过了但是还是会报错

color_code定义过但是他会报错，
color_code' isn't defined
而且摄像头非常的黑，换了一个摄像头就是正常亮度，

import sensor, image, time, math,pyb,utime
from pyb import UART #引入串口通信
from pyb import LED  #提示

red_led = LED(1)
green_led = LED(2)
blue_led = LED(3)



global left,middle,right,VAL
global color
global flag_color  #标志变量


left = 0
middle = 0
right = 0

flag_color = 0

red_threshold = (37, 64, 44, 127, -128, 127)
green_threshold = (18, 68, -62, -28, -128, 127)
blue_threshold = (46, 13, -33, 14, -52, -9) #红、绿、蓝颜色阈值

red_color_code = 1
green_color_code = 2
blue_color_code = 4
black_color_code = 8

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False) # 关闭自动增益
sensor.set_auto_whitebal(False) # 关闭白平衡
clock = time.clock()

uart = UART(3,9600) #初始化串口通信

def Light():
    red_led.on()
    green_led.on()
    blue_led.on()

if flag_color == 0:
   flag_color = 1

#二维码读取
while(flag_color == 1):
    clock.tick()
    img0 = sensor.snapshot()
    img0.lens_corr(1.8)
    for QR in img0.find_qrcodes():
        code = QR.payload()
        img0.draw_rectangle(QR.rect(),color = (255,48,48))
        if code == '绿色蓝色':
            utime.sleep_ms(2000)
            uart.write('23')
            uart.write('0')
            print('23')
            flag_color = 2
            break
        if code == '绿色红色':
            utime.sleep_ms(2000)
            uart.write('21')
            uart.write('0')
            print('21')
            flag_color = 2
            break
        if code == '蓝色绿色':
            utime.sleep_ms(2000)
            uart.write('32')
            uart.write('0')
            print('32')
            flag_color = 2
            break
        if code == '蓝色红色':
            utime.sleep_ms(2000)
            uart.write('31')
            uart.write('0')
            print('31')
            flag_color = 2
            break
        if code == '红色绿色':
            utime.sleep_ms(2000)
            uart.write('12')
            uart.write('0')
            print('12')
            flag_color = 2
            break
        if code == '红色蓝色':
            utime.sleep_ms(2000)
            uart.write('13')
            uart.write('0')
            print('13')
            flag_color = 2
            break


#标志变量为2时
while(flag_color == 2):
    clock.tick()
    img = sensor.snapshot()

    #在三个框里识别物体
    img.draw_rectangle((18,80,82,102),color=(0xff,0xff,0xff))
    img.draw_rectangle((118,74,100,106),color=(0xff,0xff,0xff))
    img.draw_rectangle((238,70,78,102),color=(0xff,0xff,0xff))

    #识别左、中、右三个物块
    blob_left = img.find_blobs([red_threshold,green_threshold,blue_threshold],area_threshold = 200,merge = True,roi = (18,80,82,102))
    blob_middle = img.find_blobs([red_threshold,green_threshold,blue_threshold],area_threshold = 200,merge = True,roi = (118,74,100,106))
    blob_right = img.find_blobs([red_threshold,green_threshold,blue_threshold],area_threshold = 200,merge = True,roi = (238,70,78,102))

    left = 0
    middle = 0
    right = 0

    #判断左侧物体颜色
    if blob_left:
        for blob in blob_left:
            x = blob[0]
            y = blob[1]
            width = blob[2]
            height = blob[3]
            center_x = blob[5]
            center_y = blob[6]
            color_code = blob[8]

        #添加颜色说明
        if color_code == red_color_code:
            img.draw_string(x, y,  'red',color = (0xff,0x00,0x00))
            left = 1
        elif color_code == green_color_code:
            img.draw_string(x,y-10,"green",color = (0x00,0xff,0x00))
            left = 2
        elif color_code == blue_color_code:
            img.draw_string(x,y-10,"blue",color = (0x00,0x00,0xff))
            left = 3
        color = color_code
        img.draw_rectangle(x,y,width,height)
        img.draw_cross(center_x,center_y)

    #判断中间物体颜色
    if blob_middle:
        for blob in blob_middle:
            x = blob[0]
            y = blob[1]
            width = blob[2]
            height = blob[3]
            center_x = blob[5]
            center_y = blob[6]
            color_code = blob[8]

        #添加颜色说明
        if color_code == red_color_code:
            img.draw_string(x,y-10,"red",color = (0xff,0x00,0x00))
            middle = 1
        elif color_code == green_color_code:
            img.draw_string(x,y-10,"green",color = (0x00,0xff,0x00))
            middle = 2
        elif color_code == blue_color_code:
            img.draw_string(x,y-10,"blue",color = (0x00,0x00,0xff))
            middle = 3
        color = color_code
        img.draw_rectangle(x,y,width,height)
        img.draw_cross(center_x,center_y)

    #判断右侧物体颜色
    if blob_right:
       for blob in blob_right:
           x = blob[0]
           y = blob[1]
           width = blob[2]
           height = blob[3]
           center_x = blob[5]
           center_y = blob[6]
           color_code = blob[8]

    #添加颜色说明
    if color_code == red_color_code:
       img.draw_string(x,y-10,"red",color = (0xff,0x00,0x00))
       right = 1
    elif color_code == green_color_code:
       img.draw_string(x,y-10,"green",color = (0x00,0xff,0x00))
       right = 2
    elif color_code == blue_color_code:
       img.draw_string(x,y-10,"blue",color = (0x00,0x00,0xff))
       right = 3
    color = color_code
    img.draw_rectangle(x,y,width,height)
    img.draw_cross(center_x,center_y)

    if left!=0 and middle != 0 and right != 0 and left != middle and left != right and right != middle:
        #123
        if left == 1 and middle == 2 and right == 3:
            print("%d%d%d" % (left,middle,right))
            uart.write('123')
            utime.sleep_ms(5000)
            flag_color =3
        #132
        if left == 1 and middle == 3 and right == 2:
            print("%d%d%d" % (left,middle,right))
            uart.write('132')
            utime.sleep_ms(5000)
            flag_color =3
        #213
        if left == 2 and middle == 1 and right == 3:
            print("%d%d%d" % (left,middle,right))
            uart.write('213')
            utime.sleep_ms(5000)
            flag_color =3
        #231
        if left == 2 and middle == 3 and right == 1:
            print("%d%d%d" % (left,middle,right))
            uart.write('231')
            utime.sleep_ms(5000)
            flag_color =3
        #312
        if left == 3 and middle == 1 and right == 2:
            print("%d%d%d" % (left,middle,right))
            uart.write('312')
            utime.sleep_ms(5000)
            flag_color =3
        #321
        if left == 3 and middle == 2 and right == 1:
            print("%d%d%d" % (left,middle,right))
            uart.write('321')
            utime.sleep_ms(5000)
            flag_color =3

#当标志变量变为3时：
while(flag_color == 3):

    clock.tick()
    img = sensor.snapshot()

    #在三个框里识别物体
    img.draw_rectangle((18,80,82,102),color=(0x00,0x00,0x00))
    img.draw_rectangle((118,74,100,106),color=(0x00,0x00,0x00))
    img.draw_rectangle((238,70,78,102),color=(0x00,0x00,0x00))

    #识别左、中、右三个物块
    blob_left = img.find_blobs([red_threshold,green_threshold,blue_threshold],area_threshold = 200,merge = True,roi = (18,80,82,102))
    blob_middle = img.find_blobs([red_threshold,green_threshold,blue_threshold],area_threshold = 200,merge = True,roi = (118,74,100,106))
    blob_right = img.find_blobs([red_threshold,green_threshold,blue_threshold],area_threshold = 200,merge = True,roi = (238,70,78,102))

    left = 0
    middle = 0
    right = 0

    #判断左侧物体颜色
    if blob_left:
        for blob in blob_left:
            x = blob[0]
            y = blob[1]
            width = blob[2]
            height = blob[3]
            center_x = blob[5]
            center_y = blob[6]
            color_code = blob[8]

        #添加颜色说明
        if color_code == red_color_code:
            img.draw_string(x, y,  'red',color = (0xff,0x00,0x00))
            left = 1
        elif color_code == green_color_code:
            img.draw_string(x,y-10,"green",color = (0x00,0xff,0x00))
            left = 2
        elif color_code == blue_color_code:
            img.draw_string(x,y-10,"blue",color = (0x00,0x00,0xff))
            left = 3
        color = color_code
        img.draw_rectangle(x,y,width,height)
        img.draw_cross(center_x,center_y)

    #判断中间物体颜色
    if blob_middle:
        for blob in blob_middle:
            x = blob[0]
            y = blob[1]
            width = blob[2]
            height = blob[3]
            center_x = blob[5]
            center_y = blob[6]
            color_code = blob[8]

        #添加颜色说明
        if color_code == red_color_code:
            img.draw_string(x,y-10,"red",color = (0xff,0x00,0x00))
            middle = 1
        elif color_code == green_color_code:
            img.draw_string(x,y-10,"green",color = (0x00,0xff,0x00))
            middle = 2
        elif color_code == blue_color_code:
            img.draw_string(x,y-10,"blue",color = (0x00,0x00,0xff))
            middle = 3
        color = color_code
        img.draw_rectangle(x,y,width,height)
        img.draw_cross(center_x,center_y)

    #判断右侧物体颜色
    if blob_right:
       for blob in blob_right:
           x = blob[0]
           y = blob[1]
           width = blob[2]
           height = blob[3]
           center_x = blob[5]
           center_y = blob[6]
           color_code = blob[8]

    #添加颜色说明
    if color_code == red_color_code:
       img.draw_string(x,y-10,"red",color = (0xff,0x00,0x00))
       right = 1
    elif color_code == green_color_code:
       img.draw_string(x,y-10,"green",color = (0x00,0xff,0x00))
       right = 2
    elif color_code == blue_color_code:
       img.draw_string(x,y-10,"blue",color = (0x00,0x00,0xff))
       right = 3
    color = color_code
    img.draw_rectangle(x,y,width,height)
    img.draw_cross(center_x,center_y)

    if left!=0 and middle != 0 and right != 0 and left != middle and left != right and right != middle:
        #123
        if left == 1 and middle == 2 and right == 3:
            print("%d%d%d" % (left,middle,right))
            uart.write('123')
            flag_color =4
        #132
        if left == 1 and middle == 3 and right == 2:
            print("%d%d%d" % (left,middle,right))
            uart.write('132')
            flag_color =4
        #213
        if left == 2 and middle == 1 and right == 3:
            print("%d%d%d" % (left,middle,right))
            uart.write('213')
            flag_color =4
        #231
        if left == 2 and middle == 3 and right == 1:
            print("%d%d%d" % (left,middle,right))
            uart.write('231')
            flag_color =4
        #312
        if left == 3 and middle == 1 and right == 2:
            print("%d%d%d" % (left,middle,right))
            uart.write('312')
            flag_color =4
        #321
        if left == 3 and middle == 2 and right == 1:
            print("%d%d%d" % (left,middle,right))
            uart.write('321')
            flag_color =4
#####完成扫描
while(flag_color == 4):
    green_led.on()