SPIRIT-CSolar Powered Image Response Infrared Tracking CamcorderJustin EilerJeff Morroni Adeel BaigAndy CrahanJim Patterson

OverviewDesign an infrared tracking camcorderAll components solar poweredStepper Motors control camera movementPyro-electric sensors detect IR emissionSpartan-3 + PicoBlaze provides system control

Presentation OutlineSystem ComponentsManual Control Adeel BaigSolar Power System Jeff MorroniStepper Motor Controllers Jeff MorroniInfrared Sensors Andy Crahan and Adeel BaigSystem Integration Jim PattersonSoftware Justin Eiler, Jim Patterson, Andy CrahanSystem Mounting Justin EilerParts List, Schedule, and Milestones

System Block DiagramPeak Power TrackerDeep Cycle BatterySolar PanelStepper MotorsMotor Controller PCBVoltage/Current SensorsIR Sensor PCB with A/D Converters Digital CamcorderSpartan-3LEDComputerDataPowerMechanical

Manual ControlGenesis controller has a DB-9 interfaceThe controller is active lowWhen a switch is pressed, the output is shorted to ground

74HC157Quad 2 line to 1 line multiplexer2 inputs for every output1 select signal for the chip

Controller Pins

Solar Power SystemPeak Power TrackerDeep Cycle BatterySolar PanelStepper MotorsMotor ControllerVoltage/Current SensorsIR Sensor PCB with A/D ConvertersDigital CamcorderSpartan-3

Flyback Converter and Current/Voltage SensorsFPGA controls Peak Power and Converter ShutoffUses voltage and current sensors to compute peak power point and determine if battery is charged

Current and Voltage SensorsLMP8270 uses common mode voltage to sense currentSimple Voltage Divider Senses VoltageFPGA computes peak power point and battery charge state

Solar PanelSharp NE-80EJE donated from Namaste Solar Electric80W, 17.1 Vmax, 4.67 ImaxLength of 4.0Width of 1.8

Deep Cycle Battery105 Amp Hours12.5V nominal output

Solar Power System StatusFlyback converter built and testedDeep Cycle battery integrated with flyback converterSolar cells modeled with resistor in series with a voltage source

Chart1

1.6102

1.7628

1.7933

1.7408

1.7353

1.70136

1.6646

1.61938

1.57126

1.5435

1.5312

1.394

1.3851

1.30032

1.2564

1.20743

1.20743

1.1844

Duty Cycle

Input Power

Peak Power Model

Sheet1

Duty CycleVoltageCurrentPower

0.289.70.1661.6102

0.357.80.2261.7628

0.377.90.2271.7933

0.46.80.2561.7408

0.426.70.2591.7353

0.446.120.2781.70136

0.475.80.2871.6646

0.55.380.3011.61938

0.525.020.3131.57126

0.554.90.3151.5435

0.574.80.3191.5312

0.64.10.341.394

0.624.050.3421.3851

0.653.780.3441.30032

0.683.490.361.2564

0.73.290.3671.20743

0.733.290.3671.20743

0.763.290.361.1844

Sheet1

Duty Cycle

Input Power

Peak Power Model

Sheet2

Sheet3

Motor Controller Schematic

L297 Stepper Motor ControllerHalf/Full Step CapabilityDirection InputEnable InputClock Input

L298 Dual Full-Bridge DriverCapable of Driving Motors up to 2ACurrent Sensing Capability allows for quick current decay when windings are turned off

Stepper Motor0.8A Winding Current0.9 degree step sizes

Subsystem Stepper/Stepper Control (contd)

Stepper motor control taken from Jason Johnsons Stepper Motor page 1998Timing Diagram and Pinout taken from Shinano Kenshi Introduction to Stepper Motors Page

PCB Layout

Pyro-electric IR SensorsOnly pyro-electric sensors have the rapid motion detection we require for high speed filmingThese operate like current sources with output proportional to the rate of change in temperatureExtremely fast responses set them apartThey are also insensitive to external DC effects

Current PIR StatusSuccessful testing of PIR directional signal generationAmplification and filtering circuit performs as desired, railing the right and left movement signals to 5VThis is dropped to 3.3V for direct signal interpretation on the FPGA

PIR Output Filter, Amplification, and Latching

Gain stage 1 sets amplifier gain and DC operating pointAlso creates band-pass filter to amplify only signals above DC yet below 10Hz

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

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

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

Multi-vibrator IC used to latch output signals

Circuit Timing Issues: MultivibratorThe 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.

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

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.

Motion SensitivityThis 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 feetFor the design expo we are optimizing the PIR sensitivity for approximately 8 feet

Spartan-3 and PicoBlaze

PicoBlaze Features 16 byte-wide general-purpose data registers1K instructions of programmable on-chip program store, automatically loaded during FPGA configurationALU: CARRY and ZERO indicator flags64-byte internal scratchpad RAMAutomatic 31-location CALL/RETURN stack2 clock cycles per instructionFast interrupt response; worst-case 5 clock cycles

Why PicoBlaze?8-bit micro-controllerExcellent for control and state machine applications

Re-uses logic resourcesInterrupt handling

System Block DiagramPeak Power TrackerDeep Cycle BatterySolar PanelStepper MotorsMotor Controller PCBVoltage/Current SensorsIR Sensor PCB with A/D Converters Digital CamcorderLEDComputerSpartan-3DataPowerMechanical

System IntegrationPicoBlaze - send control signals to ADC, DAC, and MUXesfor receiving IR sensor information and converter informationMUXes - continuously polled at 50MHz for information, scrolling through each of 15 sensors and saving current state informationADC - synchronized to 25 MHz clock signalreceive output voltage and current from converterDAC synchronized to 25 MHz clock signalsend PWM signal to gate drive converter MOSFETFPGA state machines Input - IR signal, converter voltage and currentOutputs - motor control signal, converter PWM signal

IR Sensors and Converter ControlVoltage RegulatorIR signal processingConverter controlOutput

IR signal processingHeader IR sensors separately connected

IR Network separate gain stages, filtering and latching

MUXes MAX306CPIleft and right channels15 IR networksHeaderMUXes

Converter ControlADC 0808CCNconverter V and I digital signal

DAC 0830LCNdigital signal PWM voltage

Level Shifters HCF40109digital signals from 5V3.3VDACADCLevel Shifters

State MachineMove_UpMove_RightMove_DownManualAutomaticReset = 0Pad_down = 0Pad_up = 0Pad_right = 0*All 4 Move_x states return to previous state after one cycleMove_LeftPad_left = 0Pad_start = 1Start_upPad_start = 0Reset = 1

SoftwareVerilog HDL (State Machine)Manual controlIR signal flowMotor control

PicoBlaze Assembly LanguageSerial communicationSensor pollingConverter control

Example Code for Manual Controlcase (state)

MANUAL: beginautomode = 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_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

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*Verilog HDL used to code FPGA

Test Code for Micro-controllercold_start: LOAD s0, 00OUTPUT s0, FFsend_prompt:LOAD s1,ascii_Xsend_to_UART: INPUTs0, buffer_fullTESTs0, b_full JUMPZ, UART_write JUMPrs232_echoUART_write:OUTPUTs1, uart_data_txLOADs1, 00rs232_echo: INPUTs0, data_presentTESTs0, b_full JUMPZ, led_echoUART_read:INPUTs1, uart_data_rx led_echo: INPUT s0, switch_in OUTPUT s0, leds_outfinish: JUMP send_to_UART PicoBlaze has own assembly language Code tests UART, LEDs, switches, and serial portAssembler converts this to Verilog HDL code

System MountingTripod mountSolar Panel independently supported but attached to tripodPan stepper motor (possibly geared) Tilt stepper motor attached to yokeIR sensors mounted on array below top of tripod

Parts List

Project Schedule

MilestonesMilestone 1- Hardware assembled and software written- Minimal system integrationMilestone 2- Hardware and software fully integrated- System mounting completed

Questions?