def Get_phone():
#连续拍摄n张照片，每间隔3s拍摄一次。
while(n):
#红灯亮
pyb.LED(RED_LED_PIN).on()
sensor.skip_frames(time = 3000) # Give the user time to get ready.等待3s，准备一下表情。

    #红灯灭，蓝灯亮
    pyb.LED(RED_LED_PIN).off()
    pyb.LED(BLUE_LED_PIN).on()

    #保存截取到的图片到SD卡
    print(n)
    sensor.snapshot().save("singtown/s%s/%s.pgm" % (num, n) ) # or "example.bmp" (or others)

    n -= 1

    pyb.LED(BLUE_LED_PIN).off()
    print("Done! Reset the camera to see the saved image.")