Team Doki Doki: Paintball Gun IR Sensing and Tracking

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Team Doki DokiPaintball GunIR Sensing and
Tracking

• Team Members
• Matt Freeman
• James Kirby
• Juan Rivera

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Presentation Outline

• Project Overview
• System Diagram
• Input subsystem
• Processing subsystem
• Output subsystem
• Schedule
• Milestones
• Division of Labor
• Budget/Parts List

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Project Overview

• Design a paintball gun auto-detection and
  tracking system
• Implement both manual control and automatic
  control based on IR sensing
• Stepper motors control gun movement
• Linear actuator pulls trigger
• Spartan-3 provides system control

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System Diagram
Stepper Motors
ADC /MUX
Spartan-3
IR Sensors
Data
Data
Gun
Actuator
Control
User Interface
LCD
IR Transmitter
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System Input
Stepper Motors
ADC /MUX
Spartan-3
IR Sensors
Data
Data
Gun
Actuator
Control
User Interface
LCD
IR Transmitter
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IR Sensing

• IR ? emitted by humans is 10µm
• Requires exotic and expensive detectors
• Use matched IR detector/emitter pairs
• Readily available, inexpensive

HgCdTe
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IR Transmitters

• Transportable independent target
• House in self-contained multiple LED flasher
• Has different modes of operation
• Two IR LEDs for transmission and one visible LED
  for alignment and power confirmation

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IR Sensors

• Mount in an array on gun barrel
• Both fine-tuning and coarse adjustment
• Shield from light for best results
• More precise final design

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MUX

• One ADC, 8 analog inputs
• MC74HC4051 8 to 1 analog switch
• Will require 8 cycles to refresh all IR readings

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ADC

• IR sensors are analog, board input is digital
• AD7821 8 bit parallel analog to digital
  converter
• VREF/- allows for fine-tuning of voltage of one
  LSB

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IR/MUX/ADC Schematic
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Manual Control Interface

• Modified 8-bit NES controller
• Controls switching between operation modes
• Controls manual and calibration functioning

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Manual Control Interface

• Parallel control hard-wired to MC14021B
  controller chip
• Input into board via 40-pin GPIO expansion port

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System Processing
Stepper Motors
ADC /MUX
Spartan-3
IR Sensors
Data
Data
Gun
Actuator
Control
User Interface
LCD
IR Transmitter
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Spartan-3 Breakdown
SPARTAN-3
IR Data
FPGA
NES Control
State Machine
40-pin GPIO
MUX/ADC
MicroBlaze
RS-232
Serial LCD
Motor Drivers
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State Machine

• Transfer out of all move states and fire state
  controlled via variable PrevState
• Automatic mode ignores all inputs except Reset
  and NESSel

Reset1
NESRight1
Calibration
MoveUp
NESUp1
NESSel1
NESLeft1
NESUp1
MoveRight
Manual
NESRight1
MoveLeft
NESLeft1
NESB1
NESSel1
NESDown1
MoveDown
Fire
Automatic
NESDown1
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State Machine Implementation

• Big switch statement
• Registers keep track of both next state and
  previous state
• Digital lock prevents unwanted toggling
• Separate modules for clock division and display

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Initial Software Testing

• First used Spartan-3 on-board I/O, then GPIO
• Successful behavior of state machine observed
• Simulated and actual NES inputs all had correct
  effects
• L/R and U/D position each visible on two
  7-segment displays
• Manual control working in software, yet to send
  pulses to motors

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MicroBlaze

• MicroBlaze is a soft processor core from Xilinx
  for use in FPGAs
• Create an RS-232 interface for serial character
  LCD output
• Encapsulate Verilog state machine
• Cannot directly interface with GPIO ports

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System Output
Stepper Motors
ADC /MUX
Spartan-3
IR Sensors
Data
Data
Gun
Actuator
Control
User Interface
LCD
IR Transmitter
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Stepper Motors

• Provide gun left/right and up/down movement
• Chosen stepper motors have lots of torque
• Allow the system to know the position of sensor

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Motor Driver Circuit

• Bipolar Stepper
• Motor Driver
• H-bridge design
• Interface between
• Spartan-3 and motors

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Motor Driver Schematic
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Actuator

• Linear actuator physically pulls trigger
• Chosen over servo motor for faster reaction
• Can fire multiple times per second
• Mount directly on gun behind trigger
• Spring-loaded trigger pulls actuator back out
  automatically after firing

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LCD

• Character LCD chosen for ease of use
• Serial RS-232 LCD to interface with MicroBlaze
• Could display lots of different information
• Initially Debugging info
• Gun position
• Shots remaining
• IR signal strength
• Not system-crucial

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Paintball Gun

• Mounted on a Lazy Susan for left/right rotation
• Will fire safe ammunition for indoor testing

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Updated Project Schedule
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Milestone 1

• Date October 27th
• Goal Manual operation fully functional
• NES Controller properly interfaced
• Proper state machine operation
• Working motor driver circuits (wire wrap)
• Motors control gun movement

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Milestone 2

• Date November 17th
• Goal Automatic operation functional
• IR detector array finalized
• Control logic (MUX, ADC) configured
• Automatic state on FPGA taking data from IR
  sensors and sending out appropriate signals to
  motor drivers

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Add-Ons for Expo

• Get serial character LCD configured via RS-232
  using MicroBlaze
• Complete acrylic housing
• Ability to see all guts of system
• Mount CMOS video camera on gun barrel

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Division of Labor

• Matt Circuit Design and System Integration
• James Data Processing and Software Design
• Juan Structure and Circuit Design and
  Implementation

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Project Budget/Parts List
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Questions?
?