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Easy on the Tini

Easy on the Tini. Cell phone detector. Bill Barker Carey Davis Ben Irwin Travis Majors. Description and Goals. To create a robot that detects RF signals (cell phone signals) then moves toward the strongest signal. Notifies cell phone user about use in that area. Outline of Approach.

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Easy on the Tini

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  1. Easy on the Tini Cell phone detector Bill Barker Carey Davis Ben Irwin Travis Majors

  2. Description and Goals • To create a robot that detects RF signals (cell phone signals) then moves toward the strongest signal. • Notifies cell phone user about use in that area.

  3. Outline of Approach • Create a robot with two servo motors • Fashion RF detecting antenna(s) on the robot chassis • Mount IR sensors to aid robot movement • Use display, lighting, sounds, etc. to deter cell phone use • Design a microcontroller to interface the systems

  4. Hardware Implementation Sharp IR Detectors (3) Tuned Yagi Antenna Diode Rectification Circuit Digital Compass Module A/D Input I2C Interface Microcontroller MSP4301611 Low Noise Amplifier Data/ Programming interface JTAG Interface PWM Signal Outputs Signal Disruption Motor Drivers ServoDisc Motors

  5. Software Flow Diagram System Ok Move Forward Turn 90o Read Compass and Antenna Value Turn to match degrees of strongest signal Forward Signal Disruption Rotate 180o Count=2? Count + 1 Reached Object? 1 3 1 2 3 Find Strong Signal? Object? Rotated 360o? no yes no no no Timer Going? Try to detect signal yes yes no yes 2 yes 2 yes no yes no Signal still there?

  6. The Robot • Metal platform from previous project • Two 9FGHD Ferrite Series ServoDisc Motors

  7. Robot Movement • Autonomous • Object Detection • Infra-Red • Home Base Detection • RF • Programmable Search Pattern • Signal Detection Sweep • Identify and approach appropriate signal

  8. Scenario#1 No Signal Found Signal Found Object Detected No Signal Found

  9. Wave Reflection • Signal waves reflect off of Metal Surfaces • Constructive Phase alignment creates false positives • Solution: Continue to monitor signal while approaching source.

  10. Scenario#2 Signal Found Reflected Waves SignalPresent SignalLost False Positive! Destructive Phase Constructive Phase Signal Found Metal Surface

  11. The Motor • 9FGHD Ferrite Series ServoDisc Motor • Input voltage -12V to +12V • Capable of 1.5 N-m continuous torque

  12. Motor Drivers • LMD18200t

  13. Sign/Magnitude PWM Control

  14. PWM Control Circuitry

  15. Digital Compass Module • I2C 2-Wire Serial Interface • 3.3v supply voltage • 1/2 degree heading resolution • Firmware Included

  16. I2C Module

  17. I2C Communication

  18. Compass Command Bytes

  19. Getting compass data Heading Mode: The heading output data will be the value in tenths of degrees from zero to 3599 and provided in binary format over the two bytes.

  20. Signal Detection

  21. Robot Signal Detection • Overview: This part of the robot will detect signals within the GSM frequency-band that will then be amplified by a Low Noise Amplifier, rectified into a DC voltage, then finally interpreted by our microcontrollers A/D converter. • This will be done by the following devices: • Tuned directional antenna • RF signal amplifier and diode rectifier • MSP430 A/D Converter

  22. Tuned Directional Antenna • This component will give directional ordination to the robot to pursue the signal. • A Yagi antenna will be used to hone in on the signal. • Antennas Specifications: GSM: Uplink 890-915MHz and Downlink 935-960Mhz PCS band: 1.7-1.99 GHz

  23. Antenna Capability Reverse-Polarity BNC-Plug Adapter to Standard BNC-Plug

  24. Signal Amplification • 50 Ω Low Noise Amplifier • High output Gain • Low noise figure • Operates in the frequency band we require

  25. Non-rectified RF Signal Voice Call Data Message *Volt scale is 100mV *Signal is being boosted by LNA Phone 65 ° out of line Did someone say this was impossible?

  26. RF Signal Rectification Circuit • This simplified circuit will take the antenna’s RF signal as an input and will output a voltage that is proportional to the signal’s intensity. • LNA will boost signal gain to a readable voltage level. • Diodes will rectify signal to a DC voltage with minimum losses.

  27. Voltage Processing • Feed measured voltage into the micro-controller’s A/D converter. • Have the microcontroller will only sample this A/D at times of signal searching. • Store both RF intensity and robot degree of direction data for a full revolution in on-board RAM. • Find peak voltage within data and have robot return to this recorded direction.

  28. Microcontroller

  29. Microcontroller • Prototype Board for MSP430-F1611 • Multiple A/D converters, UART, and I2C peripherals • Expanded RAM to 10K bytes for greater storage capacity • PWM capabilities for motor control • Good tools and easy debugging • Cost effective solution of our application

  30. Functional Block Diagram

  31. AD Converter • We will be using the 12 Bit AD converter peripheral. • The ADC will convert voltages into integers between 0 and 4095 relative to the voltage levels. • We will be using a reference voltage of 1.5V as it gives us more resolution and we will not be inputting anything higher than that.

  32. ADC12 Module

  33. IR Object Detection • Sharp GP2D12 • Analog output voltage distance from object 10cm to 80cm • Optimal Vcc 4.5-5.5 V

  34. IR Sensor Voltage Output Curve • The IR sensors have a non-linear output voltage curve with respect to distance. • Range is from 10 to 80cm with higher voltages representing shorter distances. • 10cm-2.6v • 80cm-.4V • >80cm-.25V

  35. Home Base • If time permits we will still implement a home base. • Home Base will generate a signal to call robot home to: • Recharge • Be reprogrammed • Signal will be made by a function generator in antenna frequency range. • More testing required to see what kind of information antenna will give us.

  36. Power Distribution

  37. Voltage Variations 5 V LCD Screen IR Detectors 3.3 V Microcontroller 12 V Motor Drivers LNA Voltage Regulators LM1117 Regulate to 5 V, 3.3 V Power Distribution

  38. The Battery • 2 BP7-12 12 V 7Ah Batteries to power the robot • 5.94” x 2.56” x 3.98” • 6 lbs.

  39. Opto-isolators • HPCL-3150 • Will be used for isolation and level shifting for PWM, direction/brake signals

  40. Disruption Handling

  41. LCD Screen • Serial Enabled 16x2 LCD - Black on Green • 10k Pot to adjust contrast

  42. Schematic

  43. PCB

  44. Scheduling, Costs, and Labor

  45. Updated Schedule

  46. Separation of Tasks • Programming of Microcontroller – Travis and Ben • PCB Design – Carey • Motor driver control – Bill and Ben • Antenna – Travis, Bill • LCD screen – Ben and Carey

  47. Milestones • Milestone 1:Robot moves towards test signal • Milestone 2:Programmable search parameters, IR object detection integration, home base construction complete • Expo:Robot and home base fully functional

  48. Item Price Quantity Total Yagi Antenna 59.64 1 59.64 Battery 29.6 1 29.6 IR Sensors 12.5 3 48.99 Motor drivers 5 4 20 Dev Board and Compass 114.77 1 114.77 LNA and connectors 160 1 160 E store(perf board and headers) 20 1 20 Total so far $453 PCB 66 2 132 MSP chip 20 1 20 LCD screen 25 1 25 IR sensors 12.5 2 25 Miscellaneous 100 1 100 Estimated Total $755 Cost Estimations

  49. Thank you! ??Questions??

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