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 = (79, 43, -38, 73, 29, 102)
# 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,%d]" % (max_blob.cx(),max_blob.cy()) #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+'\r\n')
else:
print('not found!')
if max_blob.cx() > 70 and max_blob.cx() <85:
if max_blob.cy() <80:
uart.write('s')
print('s')
if max_blob.cy() >80:
uart.write('t')
print('t')
if max_blob.cx() < 70:
uart.write('l')
print('l')
if max_blob.cx() >85:
uart.write('r')
print('r')
![0_1558342482724_报错.png](https://fcdn.singtown.com/b9b0a8cc-b0bc-4313-b519-2e138364081c.png)