Team Doki Doki:
Paintball Gun
IR Sensing and Tracking
Team Members:
Matt Freeman
James Kirby
Juan Rivera
Capstone CDR Fall 2005
Presentation Outline
• Project Overview
• System Diagram
– Input subsystem
– Processing subsystem
– Output subsystem
•
•
•
•
Schedule
Milestones
Division of Labor
Budget/Parts List
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
System Diagram
IR Sensors
Data
ADC Data
Spartan-3
/MUX
Stepper
Motors
Actuator
User Interface
Control
IR
Transmitter
Capstone CDR Fall 2005
LCD
Gun
System Input
IR Sensors
Data
ADC Data
Spartan-3
/MUX
Stepper
Motors
Actuator
User Interface
Control
IR
Transmitter
Capstone CDR Fall 2005
LCD
Gun
IR Sensing
• IR λ emitted by humans is ~10μm
– Requires exotic and expensive detectors
• Use matched IR detector/emitter pairs
– Readily available, inexpensive
Capstone CDR Fall 2005
HgCdTe
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
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
MUX
• One ADC, 8
analog inputs
• MC74HC4051:
8 to 1 analog
switch
• Will require 8
cycles to
refresh all IR
readings
Capstone CDR Fall 2005
ADC
• IR sensors are analog,
board input is digital
• AD7821: 8 bit parallel
analog to digital
converter
• VREF+/- allows for finetuning of voltage of
one LSB
Capstone CDR Fall 2005
IR/MUX/ADC Schematic
+5 V
+3 .3 .V
GPIO
1
74 HCT 405 1
AD782 1
74 LVC424 5/SO
2
11
10
9
6
16
7
A
B
C
EN
VDD
VE E
X
X0
X1
X2
X3
X4
X5
X6
X7
3
1
13
14
15
12
1
5
2
4
12
11
7
8
13
20
19
VIN
+V REF
-VRE F
MODE
RD
CS
VDD
VS S
DB 0
DB 1
DB 2
DB 3
DB 4
DB 5
DB 6
DB 7
INT
OFL
WR/RDY
IR
D1
IR
D2
2
3
4
5
14
15
16
17
3
4
5
6
7
8
9
10
9
18
2
22
6
23
24
A1
A2
A3
A4
A5
A6
A7
A8
B1
B2
B3
B4
B5
B6
B7
B8
21
20
19
18
17
16
15
14
3
4
5
6
7
DIR
8
...
OE
VCCB
VCCB
74 LVC424 5/SO
IR
D3
IR
D4
IR
D5
IR
D6
3
4
5
6
7
8
9
10
2
22
IR
D7
23
24
IR
D8
Capstone CDR Fall 2005
A1
A2
A3
A4
A5
A6
A7
A8
DIR
OE
VCCB
VCCB
B1
B2
B3
B4
B5
B6
B7
B8
21
20
19
18
17
16
15
14
IR LSB
...
... MUX L SB
...
MUX
... MUX MS B
...
...
IR MSB
...
9
10
11
Manual Control Interface
• Modified 8-bit NES controller
• Controls switching between operation modes
• Controls manual and calibration functioning
Capstone CDR Fall 2005
Manual Control Interface
E1
+5 V
1
J3
2
4
J4
J1
1
1
J2
1
A1
1
1
3
U2
B2 S
B2 S
2
BT N
BT N
15
3
4
5
6
7
8
9
10
14
2
B5 S
U1
1
2
3
4
5
6
7
8
P8
Q6
Q8
P4
P3
VCC
P7
P6
P5
Q7
P2
DS
P1
C
VS S
P/S
16
13
+3 V
12
22
23
24
11
10
A1
A2
A3
A4
A5
A6
A7
A8
B1
B2
B3
B4
B5
B6
B7
B8
DIR
OE
VCCB
VCCB
21
20
19
18
17
16
15
14
3
4
5
6
7
8
...
B
A
Up
Do wn
Le ft
Ri gh t
Se l
Start
...
GPIO
74 LVC424 5/SO
9
• Parallel control hard-wired
to MC14021B controller chip
14 021
• Input into board via 40-pin
GPIO expansion port
Capstone CDR Fall 2005
System Processing
IR Sensors
Data
ADC Data
Spartan-3
/MUX
Stepper
Motors
Actuator
User Interface
Control
IR
Transmitter
Capstone CDR Fall 2005
LCD
Gun
Spartan-3 Breakdown
SPARTAN-3
FPGA
IR Data
NES Control
State Machine 40-pin
GPIO
MUX/ADC
MicroBlaze
Serial LCD RS-232
Motor Drivers
Capstone CDR Fall 2005
State Machine
Reset=1
Calibration
NESRight=1
NESUp=1
MoveUp
NESSel=1
NESLeft=1
 Transfer out of all move
states and fire state controlled
via variable PrevState
Automatic mode ignores all
inputs except Reset and
NESSel
NESUp=1
NESRight=1
MoveLeft
NESLeft=1
NESSel=1
Manual
MoveRight
NESB=1
NESDown=1
MoveDown
Automatic
NESDown=1
Capstone CDR Fall 2005
Fire
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
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
System Output
IR Sensors
Data
ADC Data
Spartan-3
/MUX
Stepper
Motors
Actuator
User Interface
Control
IR
Transmitter
Capstone CDR Fall 2005
LCD
Gun
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
Capstone CDR Fall 2005
Motor Driver Circuit
• Bipolar Stepper
Motor Driver
• “H-bridge” design
• Interface between
Spartan-3 and motors
Capstone CDR Fall 2005
Motor Driver Schematic
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
Paintball Gun
• Mounted on a Lazy Susan for left/right
rotation
• Will fire “safe” ammunition for indoor
testing
Capstone CDR Fall 2005
Updated Project Schedule
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
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
Capstone CDR Fall 2005
Division of Labor
• Matt – Circuit Design and System
Integration
• James – Data Processing and Software
Design
• Juan – Structure and Circuit Design and
Implementation
Capstone CDR Fall 2005
Project Budget/Parts List
Item
Stepper Motors (2)
Linear Actuator
IR Sensors & Mounts
Color CMOS Camera
Mounting Hardware
Fiberglass Casing
FPGA/Embedded Controller
PCB
Serial LCD
Digikey Purchases
E-Store Purchases
Aprilog Adapters
Printing/Binding Costs
Miscellaneous Electronics
Description
Vexta 2-Phase 1.1A motors
Ledex heavy-duty tubular solenoid
RadioShack matched IR emitter detectors
CM-2 from ElectronicKits.com
For gun, motors, actuator
Stationary housing
Xilinx Spartan-3
2-layer, allows for at least one revision
ILM-216 from seetron.com
PFETS: IRFZ44 and MTP2955 (20 each)
BJTS: BC547B (20)
MUX: 74HC4051N
ADC: AD7821
Level shifters: LVC4245A (3)
Perfboard, caps, etc.
24SOD3SMTS (3, SOIC to DIP)
User and technical manual
Unforeseen parts and repairs
TOTAL:
Capstone CDR Fall 2005
Estimated Price
$25
$15
$40
$86
$100
$50
$125
$150
$60
$80
$40
$40
$150
$150
$1,111
Questions?
Capstone CDR Fall 2005