没事儿了，代码是对的，同一套代码，昨天不行今天又行了，炒！

我是想用uart3传输板子，uart1传输PC串口看，同时传输同一组数据，但uart3正常传输，uart1完全没效果（先前uart3也能单独传输），然后代码就改了4个地方，仿照uart3改的4句：定义，初始化，2个传输数据语句 接口连线也没问题，连接串口前也没有打开IDE（我用自己做的串口助手，可以同时读双串口的，不是这的问题）

import sensor, image, time
import pyb
import utime
from pyb import UART
from pyb import LED
from pyb import Pin, Timer
import ustruct
EXPOSURE_TIME_SCALE = 0.001
thresholds = (100, 255)
high_threshold = (100, 255)
red_threshold = (0,100,   0,127,   0,127)
brightness = 0
uart = UART(3, 115200)
uart1 =UART(1, 115200)
uart.init(115200, bits=8, parity=None, stop=1)
uart1.init(115200, bits=8, parity=None, stop=1)
x_deviation = 0
y_deviation = 0
gainx = -1
gainy = -1
imageSize = 128
roi2 = (155, 110, 165, 120) 
xPositionNow = 0
yPositionNow = 0
xPositionLast = 0
yPositionLast = 0
blue_led = LED(3)
green_led = LED(2)
red_led = LED(1)
def send_data(cx, cy):
    out_data = data = ustruct.pack("<bbhhb",
                                   0x2C,
                                   0x12,
                                   int(cx),
                                   int(cy),
                                   0x5B)
    return out_data
def find_max(blobs):
    max_size = 0
    for blob in blobs:
        if blob.pixels() > max_size:
            max_blob = blob
            max_size = blob.pixels()
    return max_blob
sensor.reset()
sensor.set_pixformat(sensor.GRAYSCALE)
sensor.set_framesize(sensor.  QVGA)
sensor.skip_frames(time=900)
sensor.set_auto_gain(False)
sensor.set_auto_exposure(False, 100)
sensor.set_auto_gain(False)
sensor.set_windowing(roi2)
x1 = 0
y1 = 0
while True:
    img = sensor.snapshot()
    blobs = img.find_blobs([thresholds],x_stride=1, y_stride=1, area_threshold=10, pixels_threshold=10,merge=True,margin=1)
    for b in blobs:
        max_blob = find_max(blobs)
        img.draw_rectangle(max_blob.rect())
        img.draw_cross(max_blob.cx(), max_blob.cy())
        x1 = max_blob.cx()
        y1 = max_blob.cy()
    if len(blobs) >= 1:
        uart.write(send_data(x1, y1))
        uart1.write(send_data(x1, y1))
        print(x1,y1)
    else:
        uart.write(send_data(-1, -1))
        uart1.write(send_data(-1, -1))