em6l 发布的帖子

import sensor, image, time
from pyb import UART
import json


red_threshold = ((85, 43, 60, 96, -65, 38))


sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.RGB565) # use RGB565.
sensor.set_framesize(sensor.QVGA) # use QVGA for speed.
sensor.skip_frames(10) # Let new settings take affect.
sensor.set_auto_whitebal(False) # turn this off.
clock = time.clock() # Tracks FPS.

uart = UART(1, 9600)

def find_max(blobs):
    max_pixels=0
    for blob in blobs:
        if blob[4] > max_pixels:
            max_blob=blob
            max_pixels = blob[4]
    return max_blob

while(True):
    clock.tick()
    img = sensor.snapshot() # Take a picture and return the image.

    blobs = img.find_blobs([red_threshold])
    if blobs:
        max_blob=find_max(blobs)
        img.draw_rectangle(max_blob.rect())
        img.draw_cross(max_blob.cx(), max_blob.cy())
        pcx=max_blob.cx()
        pcy=max_blob.cy()
        cxy={"cx":pcx,"cy":pcy}

        uart.write(json.dumps(cxy) + '\r\n')
        print('you send:',cxy)

比如上面这样的代码，检测色块中心坐标并通过串口发出来，比如我现在想要500ms发一次，应该如何设置？我试过加延时函数500ms，但是发现摄像头的图像变得特别卡，好像不行