Nerf Dart Sentry Gun

Using Raspberry Pi 3 and Microsoft Kinect Sensor

Brian Kuo, Michael Cao, Nicholas McGilvray, Renato Maues

 

 

 

Overview

          The purpose of this project is to construct a sentry gun robot that autonomously tracks movement and fires a Nerf dart once a target has been found. A Raspberry Pi 3 is used to control the system consisting of a Microsoft Kinect, 2 DC motors powering the wheels of the robot, and a servo motor pulling the trigger on a Nerf gun. The Kinect gathers the depth data, while the tracking algorithm moves the motors to center the target and enables the servo to pull the gun’s trigger.

 

Parts Needed

      Raspberry Pi - Adafruit: https://www.adafruit.com/category/175

      Microsoft Kinect v1 (XBOX 360 Kinect) - Gamestop: http://www.gamestop.com/xbox-360/accessories/xbox-360-kinect-sensor-with-kinect-adventures/78103

      Nerf Gun - WalMart: https://www.walmart.com/ip/Nerf-N-Strike-Mega-BigShock-Blaster/44441064

      Sparkfun Shadow Chassis

      2 DC Motors

      Dual H Bridge Motor Driver

      Servo Motor

      5V external Power Supply

 

Downloading Raspbian onto your Pi

Raspbian is a unix-based OS built specifically for the Raspberry Pi, and is what the project is built on since it interfaces well with the Kinect sensor. The installation guide can be found here: https://www.raspberrypi.org/downloads/raspbian/\. Download Raspbian if you don’t already have it.

 

 

 

 

Downloading the Kinect and WiringPi Libraries

          Start your project with the free Kinect software libraries offered by OpenKinect. The libfreenect libraries are found here: https://github.com/OpenKinect/libfreenect. In this library you can find useful examples that can be useful for further implementation with the Kinect sensor.

          The WiringPi libraries are used to allow the Raspberry Pi to utilize its GPIO pins to talk to each I/O device. The WiringPi libraries can be found here: http://wiringpi.com/download-and-install/.  

 

Project Source Code

sentrycode.txt

 

Wiring Tables

The following wiring tables outlines the connections needed in order to hook up the Raspberry Pi, Kinect sensor, DC motors, H-Bridge Driver, servo motor, and external power supply.

H-Bridge Motor Driver, DC Motors

 

Raspberry Pi

H-Bridge

DC Motor 1

DC Motor 2

External 5V Supply

GND

GND (3)

 

 

GND

VCC (Pin 1)

VCC

 

 

 

 

VMOT

 

 

+5V

PWM1 (Pin 3)

PWMA

 

 

 

DigitalOut1 (Pin 5)

AIN1

 

 

 

DigitalOut2 (Pin 7)

AIN2

 

 

 

PWM2 (Pin 8)

PWMB

 

 

 

DigitalOut3 (Pin 10)

BIN1

 

 

 

DigitalOut4 (Pin 12)

BIN2

 

 

 

 

AO1

+Wire

 

 

 

AO2

-Wire

 

 

 

BO1

 

+Wire

 

 

BO2

 

-Wire

 

 

 

Servo Motor

 

Raspberry Pi

Servo Motor

5V External Supply

PWM3 (Pin 9)

PWM Wire

 

 

+5V Wire

+5V

 

GND

GND

 

 

 

 

 

 

 

Kinect Sensor

 

 

Raspberry Pi

Kinect Sensor

USB

USB

 

 

Sentry Gun Robot in Action

https://www.youtube.com/watch?v=WCyDu8QLhGA

 

 

 

 

Make it Battery Powered

The Nerf Dart sentry gun can be completely battery operated! The Kinect runs off a 12V DC power supply, which can be purchased and recharged for later use. Be careful not to buy one too heavy, or else the robot will not be able to stand the weight while turning. The Raspberry Pi and subsequent motors can be powered by a simple 5 V DC supply consisting of AA batteries. These two changes would make the sentry gun fully operational with no wires attached.