Openmv and k210 of the f question of the 2021 video game call the openmv API for line patrol, which is completely open source.

Record 201 Electric competition F The question is openmv Patrol the line , At that time, I borrowed the idea of an old brother on the Internet , I can't find the old brother , I'm sorry . I'm a rookie , If there is something wrong with the big guys, please point out .

One 、 Line patrol

1. principle

At first, I wanted to use openmv Inside the binary linear regression algorithm to do

, But it will shake after encountering the intersection , Therefore, it adopts openMv It is directly used as a line patrol sensor .

2. Grayscale Sensor

Our common line patrol sensors are generally gray-scale line patrol , The specific principle will not be introduced ,

After that, the track is red , How to say that, so there is the following openmv Line patrol , Look at two

Two 、openmv Line patrol

openmv Who can't patrol , And there are routines on the official website , Some friends will say , But there must have been other controllers at that time , This thing , Tut tut Ze , There is no time for fun in four days and three nights , Let's be specific .

1.openmv Specific route finding scheme

Two communication schemes , It is recommended to use 2

1. Serial communication

To put it simply, put openmv Become a normal sensor , Well, post the code first
roi 1-7 It is the position that needs to be detected , Adjust it by yourself according to the installation position of your car .

import sensor, image, time
from pyb import UART
uart = UART(3, 115200)
#********** Color /ROI threshold **********#
THRESHOLD = ((50, 22, 26, 75, 17, 55)) # Grayscale threshold for dark things...
roi1=(32,100,10,10)
roi2=(96,100,10,10)
roi3=(160,100,10,10)
roi4=(224,100,10,10)
roi5=(288,100,10,10)
roi6=(132,100,10,10)
roi7=(192,100,10,10)
#************ Variable ************#
a_1=a_2=a_3=a_4=a_5=0
s1=s2=s3=0
#********** Camera parameters **********#
sensor.reset()
sensor.set_vflip(True)
sensor.set_hmirror(True)
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA) # 80x60 (4,800 pixels) - O(N^2) max = 2,3040,000.
#sensor.set_windowing([0,20,80,40])
sensor.set_auto_whitebal(False)               # Create a clock object to track the FPS.
sensor.skip_frames(time = 2000)     # WARNING: If you use QQVGA it may take seconds
#********** Detect the front horizontal line subfunction **********#
def tongji():
  global a_1
  global a_2
  global a_3
  global a_4
  global a_5
  global a_6
  global a_7
  #**********1**********#
  statistics1=img.get_statistics(roi=(32,100,5,5))
  color_l1=statistics1.l_mode()
  print("color_l1:",color_l1)
  if color_l1==100:
    a_1=1
  else:
    a_1=0
  #**********2**********#
  statistics2=img.get_statistics(roi=(96,100,5,5))
  color_l2=statistics2.l_mode()
  print("color_l2:",color_l2)
  if color_l2==100:
    a_2=1
  else:
    a_2=0
  #**********3**********#
  statistics3=img.get_statistics(roi=(157,100,5,5))
  color_l3=statistics3.l_mode()
  print("color_l3:",color_l3)
  if color_l3==100:
    a_3=1
  else:
    a_3=0
  #**********4**********#
  statistics4=img.get_statistics(roi=(224,100,5,5))
  color_l4=statistics4.l_mode()
  print("color_l4:",color_l4)
  if color_l4==100:
    a_4=1
  else:
    a_4=0
  #**********5**********#
  statistics5=img.get_statistics(roi=(288,100,5,5))
  color_l5=statistics5.l_mode()
  print("color_l5:",color_l5)
  if color_l5==100:
    a_5=1
  else:
    a_5=0
  #**********6**********#
  statistics6=img.get_statistics(roi=(132,100,5,5))
  color_l6=statistics6.l_mode()
  print("color_l6:",color_l6)
  if color_l6==100:
    a_6=1
  else:
    a_6=0
  #**********7**********#
  statistics7=img.get_statistics(roi=(192,100,5,5))
  color_l7=statistics7.l_mode()
  print("color_l7:",color_l7)
  if color_l7==100:
    a_7=1
  else:
    a_7=0
  #***** Send the 7 The value of a point *****# Be similar to 7 A sensor 
  print('1a'+str(a_1))
  uart.write('1a'+str(a_1)+'\r'+'\n')
  print("a_2:",a_2)
  uart.write('2a'+str(a_2)+'\r'+'\n')
  print("a_3:",a_3)
  uart.write('3a'+str(a_3)+'\r'+'\n')
  print("a_4:",a_4)
  uart.write('4a'+str(a_4)+'\r'+'\n')
  print("a_5:",a_5)
  uart.write('5a'+str(a_5)+'\r'+'\n')
  print("a_6:",a_6)
  uart.write('6a'+str(a_6)+'\r'+'\n')
  print("a_7:",a_7)
  uart.write('7a'+str(a_7)+'\r'+'\n')
while(True):
    img = sensor.snapshot().lens_corr(strength = 1.8, zoom = 1.0).binary([THRESHOLD])
    img.draw_rectangle(roi1)
    img.draw_rectangle(roi2)
    img.draw_rectangle(roi3)
    img.draw_rectangle(roi4)
    img.draw_rectangle(roi5)
    img.draw_rectangle(roi6)
    img.draw_rectangle(roi7)
    tongji()
    s1=a_1+a_2+a_3+a_4+a_5+a_6+a_7
    if s1>6:# At the same time 7 individual , It means to recognize the horizontal line 
      uart.write('s1')
    else:  
      s2=a_1+a_2+a_3+a_6
      if s2==5: 
        uart.write('s2')  # Two kinds of T
      s3=a_3+a_4+a_5+a_7  
      if s3==5: 
        uart.write('s3')  # Two kinds of T

I believe you can understand this at a glance , Direct is to extract openmv The average color in the area where the camera acquires the image , It's white and red , See this for specific introduction Use statistics .
After that, I used 7 A place , Average distribution , Well, the more you use it, the smoother it will be , The more trouble .5 Send after simultaneous detection ’sss’, Why is 5 A? , Because the car may go askew , Write 5 It may be safer .

2.I/O mouth

The code detection part is all the same , Is to directly detect the red line and then openmv The pins are pulled up or down , Completely made into a universal color line patrol sensor , The whole code will not be posted , Let's make some changes ,I/O The code is here

from pyb import Pin

p_out = Pin('P7', Pin.OUT_PP)# Set up p_out Is the output pin 
p_out.high()# Set up p_out Pin is high 
p_out.low()# Set up p_out The pin is low 

p_in = Pin('P7', Pin.IN, Pin.PULL_UP)# Set up p_in For input pins , And turn on the pull-up resistor 
value = p_in.value() # get value, 0 or 1# Read in p_in Pin value 

Is to put if It's OK to change it
2021/11/24 Mr.li to update

3、 ... and 、K210 call openmv api To patrol the line

forehead , Words K210 use openmv Of api It's very convenient and really fragrant. After all, it's one piece openmv You can buy two yuan at any price K210 了 , Without further ado, let's get to work

1. Update firmware

stay here Download tape openmv Word firmware

Then the firmware is burned to the board
If you can't burn, please see here

2. Program

import sensor,image,lcd
import KPU as kpu
from Maix import FPIOA
from Maix import GPIO
#**************** Camera parameter settings ************#
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.set_hmirror(0)
sensor.set_vflip(0)
sensor.set_auto_gain(1,200)
sensor.run(1)
lcd.init(freq=15000000)
lcd.rotation(0)
sensor.skip_frames(time = 2000)     # WARNING: If you use QQVGA it may take seconds
#********** Color /ROI threshold **********#
THRESHOLD = ((50, 22, 26, 75, 17, 55)) # Grayscale threshold for dark things...
roi1=(32,100,10,10)
roi2=(96,100,10,10)
roi3=(160,100,10,10)
roi4=(224,100,10,10)
roi5=(288,100,10,10)
roi6=(132,100,10,10)
roi7=(192,100,10,10)
#************ Variable ************#
a_1=a_2=a_3=a_4=a_5=0
s=0
#***********I/O To configure ***********#
fpioa = FPIOA()
fpioa.set_function(0,fpioa.GPIOHS1)
led0 = GPIO(GPIO.GPIOHS1,GPIO.OUT)
fpioa.set_function(1,fpioa.GPIOHS2)
led1 = GPIO(GPIO.GPIOHS2,GPIO.OUT)
fpioa.set_function(2,fpioa.GPIOHS3)
led2 = GPIO(GPIO.GPIOHS3,GPIO.OUT)
fpioa.set_function(3,fpioa.GPIOHS6)
led3 = GPIO(GPIO.GPIOHS6,GPIO.OUT)
fpioa.set_function(6,fpioa.GPIOHS7)
led6 = GPIO(GPIO.GPIOHS7,GPIO.OUT)
#*********** Statistics *************#
def tongji():
  global a_1
  global a_2
  global a_3
  global a_4
  global a_5
  global a_6
  global a_7
  #**********1**********#
  statistics1=img.get_statistics(roi=(32,100,5,5))
  color_l1=statistics1.l_mode()
  print("color_l1:",color_l1)
  if color_l1==100:
    a_1=1
    led0.value(1)
  else:
    a_1=0
    led0.value(0)
  #**********2**********#
  statistics2=img.get_statistics(roi=(96,100,5,5))
  color_l2=statistics2.l_mode()
  print("color_l2:",color_l2)
  if color_l2==100:
    a_2=1
    led1.value(1)
  else:
    a_2=0
    led1.value(0)
  #**********3**********#
  statistics3=img.get_statistics(roi=(157,100,5,5))
  color_l3=statistics3.l_mode()
  print("color_l3:",color_l3)
  if color_l3==100:
    a_3=1
    led2.value(1)
  else:
    a_3=0
    led2.value(0)
  #**********4**********#
  statistics4=img.get_statistics(roi=(224,100,5,5))
  color_l4=statistics4.l_mode()
  print("color_l4:",color_l4)
  if color_l4==100:
    a_4=1
    led3.value(1)
  else:
    a_4=0
    led3.value(0)
  #**********5**********#
  statistics5=img.get_statistics(roi=(288,100,5,5))
  color_l5=statistics5.l_mode()
  print("color_l5:",color_l5)
  if color_l5==100:
    a_5=1
    led6.value(1)
  else:
    a_5=0
    led6.value(0)
while(True):
    img = sensor.snapshot().binary([THRESHOLD])
    img.draw_rectangle(roi1)
    img.draw_rectangle(roi2)
    img.draw_rectangle(roi3)
    img.draw_rectangle(roi4)
    img.draw_rectangle(roi5)
    img.draw_rectangle(roi6)
    img.draw_rectangle(roi7)
    tongji()
    s=a_1+a_2+a_3+a_4+a_5
    if s>5:# At the same time 5 individual , It means to recognize the horizontal line 
      print('sss')

3. Use

Same as other sensors ,I/O Will be output , Adjust according to your car ROI