没有加电路，直接接正负极

opemmv2产生的

openMV我用5V供电，通过串口发数据发送到Adurino的时候，Openmv会发出声音，类似于噪声，这是为什么呢？

....

Blob Detection and uart transport

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

For color tracking to work really well you should ideally be in a very, very,

very, controlled enviroment where the lighting is constant...

yellow_threshold = (75, 26, 24, -29, -67, -31)

You may need to tweak the above settings for tracking green things...

Select an area in the Framebuffer to copy the color settings.

sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.RGB565) # use RGB565.
sensor.set_framesize(sensor.QQVGA) # use QQVGA 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(3, 115200)
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

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

blobs = img.find_blobs([yellow_threshold])
if blobs:
    max_blob=find_max(blobs)
    print('sum :', len(blobs))
    img.draw_rectangle(max_blob.rect())
    img.draw_cross(max_blob.cx(), max_blob.cy())

    output_str="[%d]" % (max_blob.cx()-img.width()/2) #方式1
    #output_str=json.dumps([max_blob.cx(),max_blob.cy()]) #方式2
    print('you send:',output_str)
    uart.write(output_str)
else:
    print('not found!')