Python + Arduino motion to LED display

arduino_LED_adjuster.ino

//setup pins (note, using all PWM pins)
int led1 = 3;
int led2 = 5;
int led3 = 6;
int led4 = 9;
int led5 = 10;
int led6 = 11;

//Setup serial strings and substrings 
String Signal;   
String sub1;
String sub2;
String sub3;
String sub4;
String sub5;
String sub6;
int subInt;

//Start serial connection and set LED pins to output  
void setup() {
  Serial.begin(115200); 
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(led5, OUTPUT);
  pinMode(led6, OUTPUT);
  
}
 
void loop() {
  //run loop whole serial connection present  
  while (Serial.available()==0) {             

  //break down main string  
  Signal = Serial.readString();  
  sub1 = Signal.substring(0,3);
  sub2 = Signal.substring(3,6);
  sub3 = Signal.substring(6,9);
  sub4 = Signal.substring(9,12);
  sub5 = Signal.substring(12,15);
  sub6 = Signal.substring(15,18);

  //convert string sections to intigers 
  //vrite set intiger values as brightness for LEDs 
  subInt = sub1.toInt(); 
  analogWrite(led1, subInt);       

  subInt = sub2.toInt();
  analogWrite(led2, subInt); 

  subInt = sub3.toInt();    
  analogWrite(led3, subInt);       

  subInt = sub4.toInt();
  analogWrite(led4, subInt);   

  subInt = sub5.toInt();
  analogWrite(led5, subInt);       

  subInt = sub6.toInt();
  analogWrite(led6, subInt); 
  }
  
}

Camara_motion_capture.py

#!/usr/bin/env python

import cv2, serial, time

#motion detect
def diffImg(t0, t1, t2):
  d1 = cv2.absdiff(t2, t1)
  d2 = cv2.absdiff(t1, t0)
  return cv2.bitwise_and(d1, d2)

#initiate serial connection
ser = serial.Serial('/dev/ttyACM0', 115200)

#multiply brightness value 
ard_mult = 10

#initiate camera 
cam = cv2.VideoCapture(0)

#create window
winName = "Movement Indicator"
cv2.namedWindow(winName, cv2.CV_WINDOW_AUTOSIZE)


# Read three images first:
t_minus = cv2.cvtColor(cam.read()[1], cv2.COLOR_RGB2GRAY)
t = cv2.cvtColor(cam.read()[1], cv2.COLOR_RGB2GRAY)
t_plus = cv2.cvtColor(cam.read()[1], cv2.COLOR_RGB2GRAY)

#main loop
while True:
  #crop image to sections
  main_image = diffImg(t_minus, t, t_plus) 
  cr_image1 = main_image[1:480, 1:106]
  cr_image2 = main_image[1:480, 106:212]
  cr_image3 = main_image[1:480, 212:318]
  cr_image4 = main_image[1:480, 318:424]
  cr_image5 = main_image[1:480, 424:530]
  cr_image6 = main_image[1:480, 530:636]
  
  #calculate mean brightness of image sections
  cr_image1_val = cv2.mean(cr_image1)
  cr_image1_val_int = (int(cr_image1_val[0]) * ard_mult)

  cr_image2_val = cv2.mean(cr_image2)
  cr_image2_val_int = (int(cr_image2_val[0]) * ard_mult)

  cr_image3_val = cv2.mean(cr_image3)
  cr_image3_val_int = (int(cr_image3_val[0]) * ard_mult)

  cr_image4_val = cv2.mean(cr_image4)
  cr_image4_val_int = (int(cr_image4_val[0]) * ard_mult)

  cr_image5_val = cv2.mean(cr_image5)
  cr_image5_val_int = (int(cr_image5_val[0]) * ard_mult)  

  cr_image6_val = cv2.mean(cr_image6)
  cr_image6_val_int = (int(cr_image6_val[0]) * ard_mult)
  
  #write values to serial port (Arduino)
  serial_send = str(str(cr_image1_val_int).zfill(3) + str(cr_image2_val_int).zfill(3) + str(cr_image3_val_int).zfill(3) + str(cr_image4_val_int).zfill(3) + str(cr_image5_val_int).zfill(3) + str(cr_image6_val_int).zfill(3) + "\n")
  ser.write(serial_send)
  
  #add delay (Arduinio hardware needs a second to update)
  time.sleep(1)
  
		
  #display image in window
  cv2.imshow( winName, main_image) 

  
  # Read next image
  t_minus = t
  t = t_plus
  t_plus = cv2.cvtColor(cam.read()[1], cv2.COLOR_RGB2GRAY)

  #terminate program on ESC key
  key = cv2.waitKey(10)
  if key == 27:
    cv2.destroyWindow(winName)

    break