In this video I show you how to build a DIY motion tracking project with a Raspberry Pi 3. The project is autonomous so it moves and fires the gun when it detects motion. I used laser module for this project, but you can easily change modify this build to use a Nerf instead.This project allows you to detect and track a person with OpenCV and then trigger a device (such as a laser or gun).
Full tutorial for motion tracking: https://youtu.be/iwlfiDtddlg

1. Make sure pip is installed
   https://www.pyimagesearch.com/2018/09/19/pip-install-opencv/

  sudo apt-get install python pip

2. Install OpenCV 3. Follow all steps for python 3 instructions
   https://www.pyimagesearch.com/2016/04/18/install-guide-raspberry-pi-3-raspbian-jessie-opencv-3/

3. Setup I2C on your Raspberry Pi
   https://learn.adafruit.com/adafruits-raspberry-pi-lesson-4-gpio-setup/configuring-i2c

4. Install the Adafruit stepper motor HAT library
   

  sudo pip install git+https://github.com/adafruit/Adafruit-Motor-HAT-Python-Library

5. If you are using a Raspberry Pi Stepper Motor Expansion Board other than the Adafruit Stepper Motor HAT (just like in the video), then update the I2C address or frequency value with the following. (This address is only compatible with the board in the video, default value is blank for Adafruit Stepper Motor HAT)
   

  self.mh = Adafruit_MotorHAT()   to   self.mh = Adafruit_MotorHAT(0x6F)   in the source code (mertracking.py)

  for mor details: http://www.raspberrypiwiki.com/index.php/Robot_Expansion_Board

6. Make sure to create your virtual environment with the extra flag
   

  mkvirtualenv cv --system-site-packages -p python3

7. Source your bash profile
   

  source ~/.profile

8. Open Terminal and Activate your virtual environment
   

  workon cv

9. Clone this repository
   

  git clone [email protected]:MertArduino/RaspberryPi-Mertracking.git

10. Navigate to the directory
    

  cd RaspberryPi-Mertracking

11. Install dependencies to your virtual environment
    

  pip install imutils RPi.GPIO

12. Run the Code
    

  python mertracking.py

mertracking.py has a couple parameters that you can set

  MOTOR_X_REVERSED = False
  MOTOR_Y_REVERSED = False
  MAX_STEPS_X = 20
  MAX_STEPS_Y = 10
  RELAY_PIN = 22
  self.mh = Adafruit_MotorHAT(0x6f)   I2C Address or Frequency
  self.sm_x.setSpeed(5)   Speed of the Stepper Motor 1
  self.sm_y.setSpeed(5)   Speed of the Stepper Motor 2
  self.sm_x = self.mh.getStepper(200, 1)   Steps/Rev of the Stepper Motor 1
  self.sm_y = self.mh.getStepper(200, 1)   Steps/Rev of the Stepper Motor 2
  time.sleep(1)   Delay Time for the Relay Trigger

  Adafruit_MotorHAT.MICROSTEP   You can change the step type with the following commands

  MICROSTEP
  SINGLE
  DOUBLE
  INTERLEAVE