SPIRITC Solar Powered Image Response Infrared Tracking Camcorder

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SPIRIT-CSolar Powered Image Response Infrared
Tracking Camcorder
Justin Eiler Jeff Morroni Adeel Baig Andy
Crahan Jim Patterson
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Overview

• Design an infrared tracking camcorder
• All components solar powered
• Stepper Motors control camera movement
• Pyro-electric sensors detect IR emission
• Spartan-3 PicoBlaze provides system control

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Presentation Outline

• System Components
• Manual Control Adeel Baig
• Solar Power System Jeff Morroni
• Stepper Motor Controllers Jeff Morroni
• Infrared Sensors Andy Crahan and Adeel Baig
• System Integration Jim Patterson
• Software Justin Eiler, Jim Patterson, Andy
  Crahan
• System Mounting Justin Eiler
• Parts List, Schedule, and Milestones

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System Block Diagram
Solar Panel
Spartan-3
Peak Power Tracker
Voltage/Current Sensors
Data
Deep Cycle Battery
IR Sensor PCB with A/D Converters
Power
Mechanical
LED
Motor Controller PCB
Digital Camcorder
Computer
Stepper Motors
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Manual Control

• Genesis controller has a DB-9 interface
• The controller is active low
• When a switch is pressed, the output is shorted
  to ground

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74HC157

• Quad 2 line to 1 line multiplexer
• 2 inputs for every output
• 1 select signal for the chip

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Controller Pins
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Solar Power System
Solar Panel
Spartan-3
Peak Power Tracker
Voltage/Current Sensors
Deep Cycle Battery
IR Sensor PCB with A/D Converters
Motor Controller
Digital Camcorder
Stepper Motors
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Flyback Converter and Current/Voltage Sensors

• FPGA controls Peak Power and Converter Shutoff
• Uses voltage and current sensors to compute peak
  power point and determine if battery is charged

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Current and Voltage Sensors

• LMP8270 uses common mode voltage to sense current
• Simple Voltage Divider Senses Voltage
• FPGA computes peak power point and battery charge
  state

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Solar Panel

• Sharp NE-80EJE donated from Namaste Solar
  Electric
• 80W, 17.1 Vmax, 4.67 Imax
• Length of 4.0
• Width of 1.8

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Deep Cycle Battery

• 105 Amp Hours
• 12.5V nominal output

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Solar Power System Status

• Flyback converter built and tested
• Deep Cycle battery integrated with flyback
  converter
• Solar cells modeled with resistor in series with
  a voltage source

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Motor Controller Schematic
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L297 Stepper Motor Controller

• Half/Full Step Capability
• Direction Input
• Enable Input
• Clock Input

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L298 Dual Full-Bridge Driver

• Capable of Driving Motors up to 2A
• Current Sensing Capability allows for quick
  current decay when windings are turned off

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Stepper Motor

• 0.8A Winding Current
• 0.9 degree step sizes

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PCB Layout
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Pyro-electric IR Sensors

• Only pyro-electric sensors have the rapid motion
  detection we require for high speed filming
• These operate like current sources with output
  proportional to the rate of change in temperature
• Extremely fast responses set them apart
• They are also insensitive to external DC effects

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Current PIR Status

• Successful testing of PIR directional signal
  generation
• Amplification and filtering circuit performs as
  desired, railing the right and left movement
  signals to 5V
• This is dropped to 3.3V for direct signal
  interpretation on the FPGA

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PIR Output Filter, Amplification, and Latching
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• Gain stage 1 sets amplifier gain and DC operating
  point
• Also creates band-pass filter to amplify only
  signals above DC yet below 10Hz

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• Gain stage 1 feeds stage 2 through a RC high pass
  filter
• Stage 2 output (pin 14) is biased to 2.5V under
  no detection

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• Gain stage 2 feeds a window comparator of 2
  op-amps to rail the PIR signal
• Comparator provides a small voltage window for
  PIR signal to avoid noise of minor sensor
  fluctuations

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• Resistors bias comparator references to 175mV
  above and below 2.5V for left and right
  detections respectively
• Thus the window comparator provides 350mV dead
  zone centered at 2.5V to ignore noise

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• Multi-vibrator IC used to latch output signals

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Circuit Timing Issues Multivibrator

• The second gain stage feeds the CD4538 dual
  single shot multi-vibrator.
• The CD4538 is re-triggerable and re-settable for
  continuous motion detection.
• Dual chip enables left versus right signal
  processing.

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• Each single shot has an active high output
  feeding the left and right signal outputs.
• With cross coupling of the trigger inputs, the
  first single shot triggered will inhibit the
  others trigger

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• Re-triggering occurs under two successive valid
  triggers (3) and (4) prior to the output Q
  falling low.
• A re-trigger as timing node T2 increases from
  Vref1 to Vref2 causes an increase in output pulse
  width.
• Thus, continued motion during timeout will
  re-trigger the timing circuit and extend the
  pulse period until motion is no longer detected.

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Motion Sensitivity

• This window comparator enables accurate motion
  sensing for a valid trigger skateboarder,
  intruder, small child, etc.
• The PIR with a Fresnel lens mounted 0.6 inches
  off the sensor produces accurate motion detection
  in two directions (left and right or up and down)
• The Fresnel lens enables motion detection of up
  to 90 feet
• For the design expo we are optimizing the PIR
  sensitivity for approximately 8 feet

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Spartan-3 and PicoBlaze
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PicoBlaze Features

• 16 byte-wide general-purpose data registers
• 1K instructions of programmable on-chip program
  store, automatically loaded during FPGA
  configuration
• ALU CARRY and ZERO indicator flags
• 64-byte internal scratchpad RAM
• Automatic 31-location CALL/RETURN stack
• 2 clock cycles per instruction
• Fast interrupt response worst-case 5 clock
  cycles

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Why PicoBlaze?

• 8-bit micro-controller
• Excellent for control and state machine
  applications

• Re-uses logic resources
• Interrupt handling

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System Block Diagram
Solar Panel
Spartan-3
Peak Power Tracker
Voltage/Current Sensors
Data
Deep Cycle Battery
IR Sensor PCB with A/D Converters
Power
Mechanical
LED
Motor Controller PCB
Digital Camcorder
Computer
Stepper Motors
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System Integration

• PicoBlaze - send control signals to ADC, DAC, and
  MUXes
• for receiving IR sensor information and
  converter information
• MUXes - continuously polled at 50MHz for
  information, scrolling
• through each of 15 sensors and saving current
  state information
• ADC - synchronized to 25 MHz clock signal
• receive output voltage and current from
  converter
• DAC synchronized to 25 MHz clock signal
• send PWM signal to gate drive converter MOSFET
• FPGA state machines
• Input - IR signal, converter voltage and current
• Outputs - motor control signal, converter PWM
  signal

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IR Sensors and Converter Control
Converter control
Voltage Regulator
Output
IR signal processing
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IR signal processing

• Header IR sensors separately connected
• IR Network separate gain stages, filtering and
  latching
• MUXes MAX306CPI
• left and right channels

MUXes
15 IR networks
Header
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Converter Control
Level Shifters
ADC

• ADC 0808CCN
• converter V and I ? digital signal
• DAC 0830LCN
• digital signal ? PWM voltage
• Level Shifters HCF40109
• digital signals from 5V??3.3V

DAC
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State Machine
Pad_start 1
Manual
Automatic
Reset 0
Start_up
Pad_start 0
Reset 1
Pad_up 0
Pad_right 0
Pad_down 0
Pad_left 0
Move_Up
Move_Right
Move_Down
Move_Left
All 4 Move_x states return to previous state
after one cycle
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Software

• Verilog HDL (State Machine)
• Manual control
• IR signal flow
• Motor control
• PicoBlaze Assembly Language
• Serial communication
• Sensor polling
• Converter control

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Example Code for Manual Control

• case (state)
• MANUAL begin
• automode 0
• if(pad_up 1) begin
• state MOVE_UP
• if(pad_left 1) begin
• state MOVE_UP_LEFT
• end
• else if(pad_right 1) begin
• state MOVE_UP_RIGHT
• end
• end

• else if(pad_left 1) begin
• state MOVE_LEFT
• if(pad_down ! 1) begin
• state MOVE_DOWN_LEFT
• end
• else if(pad_up ! 1) begin
• state MOVE_UP_LEFT
• end
• end

• else if (pad_down 1) begin
• state MOVE_DOWN
• if(pad_left 1) begin
• state MOVE_DOWN_LEFT
• end
• else if(pad_right 1) begin
• state MOVE_DOWN_RIGHT
• end
• end

Verilog HDL used to code FPGA
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Test Code for Micro-controller

• cold_start
• LOAD s0, 00
• OUTPUT s0, FF
• send_prompt
• LOAD s1,ascii_X
• send_to_UART
• INPUT s0, buffer_full
• TEST s0, b_full
• JUMP Z, UART_write
• JUMP rs232_echo
• UART_write
• OUTPUT s1, uart_data_tx
• LOAD s1, 00
• rs232_echo
• INPUT s0, data_present
• TEST s0, b_full
• JUMP Z, led_echo
• UART_read
• INPUT s1, uart_data_rx

• PicoBlaze has own assembly language
• Code tests UART, LEDs, switches, and serial port
• Assembler converts this to Verilog HDL code

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System Mounting
Tripod mount Solar Panel independently supported
but attached to tripod Pan stepper motor
(possibly geared) Tilt stepper motor attached to
yoke IR sensors mounted on array below top of
tripod
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Parts List
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Project Schedule
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Milestones

• Milestone 1
• - Hardware assembled and software written
• - Minimal system integration
• Milestone 2
• - Hardware and software fully integrated
• - System mounting completed

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Questions?