我能看到的错误是4到9行的sensor设置不应该在死循环里。其他的没看出来什么问题。

你说的红外传感器，光学传感器，具体是什么？是摄像头sensor？还是简单的PIR或者亮度传感器。

看上去是sensor超时了，看一下摄像头模组和主板的链接是不是稳固。如果不行就寄回维修。

import sensor, image, time, network, usocket, sys
from pyb import UART
uart = UART(3, 9600)

while(True):
    uart.write("123\r\t")
    time.sleep_ms(1000)

import sensor, image, time
import pyb
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)

clock = time.clock()

last = pyb.millis()

while(True):
    clock.tick()
    img = sensor.snapshot()
    if pyb.millis() - last > 2000:
        last = pyb.millis()
        print("match_descriptor every 2s")
        ##match_descriptor
        
        
        
    #print(clock.fps())

import sensor, image, time
from pyb import Pin, Timer

tim = Timer( 4 ,freq = 500)

tim.channel(2,Timer.PWM,pin=Pin("P8"),pulse_width_percent=50)

while(True):
time.sleep_ms(1000)

Keypoints descriptor example.

This example shows how to save a keypoints descriptor to file. Show the camera an object

and then run the script. The script will extract and save a keypoints descriptor and the image.

You can use the keypoints_editor.py util to remove unwanted keypoints.

NOTE: Please reset the camera after running this script to see the new file.

import sensor, time, image

Reset sensor

sensor.reset()

Sensor settings

sensor.set_contrast(3)
sensor.set_gainceiling(16)
sensor.set_framesize(sensor.VGA)
sensor.set_windowing((320, 240))
sensor.set_pixformat(sensor.GRAYSCALE)

sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False, value=100)

FILE_NAME = "alphabet_A2"
img = sensor.snapshot()

NOTE: See the docs for other arguments

NOTE: By default find_keypoints returns multi-scale keypoints extracted from an image pyramid.

A= img.find_keypoints(max_keypoints=150, threshold=10, scale_factor=1.2)

if (A == None):
raise(Exception("Couldn't find any keypoints!"))

image.save_descriptor(A, "/%s.orb"%(FILE_NAME))
img.save("/%s.pgm"%(FILE_NAME))

img.draw_keypoints(A)
sensor.snapshot()
time.sleep(1000)
raise(Exception("Done! Please reset the camera"))

sensor.sleep(True)之后，就不能snapshopt()了，我把tick_4里面的sensor.sleep(True)注释掉可能就好了。

PS：你这个代码也写的实在没必要，一秒一秒的定时，根本不需要自己用定时器，http://doc.singtown.com/openmv_zh/openmvcam/quickref.html#id2，直接time.ticks_diff(time.ticks_ms(), start)，就行了。其实外部中断也没什么必要，直接while里检查就行了。

比如整个代码只有：

import sensor, image, utime, pyb
from pyb import Pin

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)

p8 = pyb.Pin('P8', Pin.IN, Pin.PULL_UP)

while(True):
    if p8.value()==0:
        start = utime.ticks_ms()
        print("sensor active~~~")
        sensor.sleep(False)
        sensor.snapshot()
        print("snapshot")
        print("wait 12s")
        while utime.ticks_diff(utime.ticks_ms(), start)<12000:
            pass
        print("sensor sleep~~~")
        sensor.sleep(True)

想要移植openmv里的程序，可是sensor，image等的实现代码及函数定义未知，是不是这些都是不可查的？

import pyb, sensor, image, math

sensor.reset()
sensor.set_framesize(sensor.QVGA)
sensor.set_pixformat(sensor.GRAYSCALE)

low_threshold = (0, 50)
while(True):
    for i in range(100):
        img = sensor.snapshot()
        img.binary([low_threshold])