1. SECON 2012 Midterm Presentation

2. Meet the Team Michael Helmbrecht Electrical Engineer Measurement Tasks Course Construction Chris Nicholas Computer Engineer Measurement Tasks Course Construction Kristin Sharp Electrical Engineer Measurement Tasks Course Construction Ryan Rougeau Electrical Engineer Navigation PCB Design Erin Tate Electrical Engineer Navigation PCB Design Jason Warren Computer Engineer Navigation PCB Design Dr. Robert Reese Advisor

3. Outline Competition Overview Project Overview System Design Design Constraints Approach & Tradeoff Analysis Timeline Progress and Prototype

4. Competition Overview IEEE SoutheastCon 2012 Hardware Competition Orlando, FL March 15-18, 2012 Autonomously navigate a course using the results of four tests to guide path. [1]

5. Outline Competition Overview Project Overview System Design Design Constraints Approach & Tradeoff Analysis Timeline Progress and Prototype

6. Project Overview Features: Modular/Easy to Repair Battery Life of 12 Minutes Specifications: Detects voltages Detects plate temperature Detects capacitance Differentiates between square and sawtooth waveforms Autonomous after startup Makes decisions based on measurements

7. Outline Competition Overview Project Specifications System Design Design Constraints Approach & Tradeoff Analysis Timeline Progress and Prototype

8. System Design Microcontroller LocomotionMeasurement Debug Info

9. Microcontroller Voltage Measurement Waveform Analysis Capacitance Measurement Temperature Sensing Measurement System Design

10. Microcontroller Encoders Wall Sensors Line Sensors Motors Locomotion System Design

11. Outline Competition Overview Project Overview System Design Design Constraints Approach & Tradeoff Analysis Timeline Progress and Prototype

12. Design Constraints – Practical NameDescription Voltage Measurement The robot must be able to make voltage measurements between 0V and 15V with an unknown polarity. The robot must be able to differentiate between voltages of less than 9V and those of greater than 11V. Waveform Analysis The robot must differentiate between saw-tooth and square waves with frequencies on the order of 100kHz and RMS voltage of 5V. Capacitance Measurement The robot must be able to measure an unknown capacitance between 10µF and 10nF. The robot must be able to differentiate between capacitances of less than 100nF and more than 1µF. Temperature Measurement The robot must be able to take a temperature measurement and decide whether that temperature is within 10⁰F of ambient room temperature. NavigationThe robot must be able to navigate the course autonomously using provided lines and hash marks. The robot must be able to complete at least two laps without error. [1]

13. Design Constraints – Practical TypeName ManufacturabilityModular Design SustainabilityTroubleshooting

14. Practical – Modular Design The robot must be designed to allow for quick and easy replacement of malfunctioning components – Coding – Hardware

15. Practical – Troubleshooting The robot must have remote debugging capabilities

16. Outline Meet the Team Competition Overview Project Overview System Design Design Constraints Approach & Tradeoff Analysis Timeline Progress and Prototype

17. Four Measurement Tasks Measurement of Capacitance Measurement of Voltage Measurement of Temperature Waveform Detection

18. Capacitance Measurement CHOICESPROSCONS RC Time ConstantQuick and accurate.Relies on a timer

19. Capacitance Measurement Measuring capacitance with RC time constant [2]

20. Capacitance Measurement CHOICESPROSCONS Parallel CapacitanceThe circuit, concept, and code were simple. More components

21. Capacitance Measurement Parallel Capacitance Measurement Formula: C2 = ((Vref * C1)/ADC_IN) – C1

22. Capacitance Measurement CHOICESPROSCONS Parallel CapacitanceThe circuit, concept, and code were simple. More components RC Time ConstantQuick and accurate.Relies on a timer

23. Voltage Measurement CHOICESPROSCONS Voltage Divider and Rectifier Quick and simple.123 ADC counts per volt

24. Voltage Measurement Voltage divider Thévenin Equivalent Shifter Noise Capacitor

25. Voltage Measurement @-15V 0V @15V 3V @0V 1.5V

26. Voltage Measurement CHOICESPROSCONS Operational Amplifier and comparator Distinguishing between voltages is simple. The circuit and coding is more complex than a voltage divider.

27. Voltage Measurement CHOICESPROSCONS Operational Amplifier and comparator Distinguishing between voltages is simple. The circuit and coding is more complex than a voltage divider. Voltage Divider and Rectifier Quick and simple.123 ADC counts per volt

28. Temperature Measurement CHOICESPROSCONS ProbeAccurate.Requires precise robot alignment. IR SensorFaster since no contact needed. Can sense from a distance. Less accurate (±1°F). LaserAccurate from a distance.Expensive and large.

29. Temperature Measurement CHOICESPROSCONS ProbeAccurate.Requires precise robot alignment. IR SensorFaster since no contact needed. Can sense from a distance. Less accurate (±1°F). LaserAccurate from a distance.Expensive and large.

30. Waveform Detection CHOICESPROSCONS Edge DetectionUses only µC.Wave frequency too high for µC. ComparatorWorks at all frequencies.Circuit is more complicated.

31. Waveform Detection Output waveform Input waveform V ref + -

32. Waveform Detection Square Wave Sawtooth Wave V ref

33. Waveform Detection CHOICESPROSCONS Edge DetectionUses only µC.Wave frequency too high for µC. ComparatorWorks at all frequencies.Circuit is more complicated.

34. Microcontrollers CHOICESPROSCONS 2x PIC24 28 PIN Microcontrollers - Easy parallel development phase. -Lower usable pin count. - Communication between PICs requires code/time. 1x PIC24 64 PIN Microcontroller w/ breakout -Higher usable pin count. -No extra coding. - Proven use. - More difficult to develop in parallel.

35. Microcontrollers CHOICESPROSCONS 2x PIC24 28 PIN Microcontrollers - Easy parallel development phase. -Lower usable pin count. - Communication between PICs requires code/time. 1x PIC24 64 PIN Microcontroller w/ breakout -Higher usable pin count. -No extra coding. - Proven use. - More difficult to develop in parallel.

36. Microcontrollers CHOICESPROSCONS PIC24F16KA102 28 PIN- Has onboard capacitance measurement hardware. - Lower power than PIC24HJ. - Slower clock frequency than PIC24HJ. - Only 28 pins. PIC24FJ64GA002 28 PIN- Lower power than PIC24HJ. - Had a few on hand. - Slower clock frequency than PIC24HJ. - Only 28 pins. PIC24HJ128GP506 64PIN-Has as much memory as 2 PICFJ64 series. - Faster clock speeds. - 64 pins - Needs a break out board to maintain modularity.

37. Microcontrollers CHOICESPROSCONS PIC24F16KA102 28 PIN- Has onboard capacitance measurement hardware. - Lower power than PIC24HJ. - Slower clock frequency than PIC24HJ. - Only 28 pins. PIC24FJ64GA002 28 PIN- Lower power than PIC24HJ. - Had a few on hand. - Slower clock frequency than PIC24HJ. - Only 28 pins. PIC24HJ128GP506 64PIN-Has as much memory as 2 PICFJ64 series. - Faster clock speeds. - 64 pins - Needs a break out board to maintain modularity.

38. Chassis CHOICESPROSCONS Stinger Robot Chassis -Was given to us. - High torque motors. - Robust design -Rear of chassis swings when turning. - Too large. DFRobot 2wd Mobile Platform -Round design. - Faster motors. - Delay on order.

39. Chassis CHOICESPROSCONS Stinger Robot Chassis -Was given to us. - High torque motors. - Robust design -Rear of chassis swings when turning. - Too large. DFRobot 2wd Mobile Platform -Round design. - Faster motors. - Delay on order.

40. Wall Sensors CHOICESPROSCONS Sharp 2D120X Infrared Sensor Shorter Distances (4 – 30cm)Only detects out to 30 cm. Interference when teaming. Only analog output. Maxbotix LVMaxSonar-E4 Sonar Sensor Longer Distances (6 - 254 inches) UART, PWM, and Analog output No interference when teaming Only detects down to 6 inches.

41. Wall Sensors CHOICESPROSCONS Sharp 2D120X Infrared Sensor Shorter Distances (4 – 30cm)Only detects out to 30 cm. Interference when teaming. Only analog output. Maxbotix LVMaxSonar-E4 Sonar Sensor Longer Distances (6 - 254 inches) UART, PWM, and Analog output No interference when teaming Only detects down to 6 inches.

42. Motors CHOICESPROSCONS 35:1 Metal Gearmotor 15.5Dx30L mm Higher RPM (460 RPM) Low locked current (0.6A) Low Torque (13 oz-in) Micro DC Geared Motor FIT00016 Medium Torque (26.6 oz-in) Medium RPM (200 RPM) High locked current (6A)

43. Motors CHOICESPROSCONS 35:1 Metal Gearmotor 15.5Dx30L mm Higher RPM (460 RPM) Low locked current (0.6A) Low Torque (13 oz-in) Micro DC Geared Motor FIT00016 Medium Torque (26.6 oz-in) Medium RPM (200 RPM) High locked current (6A)

44. Outline Meet the Team Competition Overview Project Overview System Design Design Constraints Approach & Tradeoff Analysis Timeline Progress and Prototype

45. Timeline AugustSeptemberOctoberNovemberDecember Strategy and Course Construction Research and Purchasing Programming Circuit Design Debugging Prototype

46. Outline Competition Overview Project Overview System Design Design Constraints Approach & Tradeoff Analysis Timeline Progress and Prototype

47. Course Construction

48. Initial Prototype

50. Locomotion Prototype Circuit Gyroscope Bluetooth Transceiver MCU Motor Controller

51. Measurement Prototype Circuit Voltage Divider and rectifier Parallel Capacitance Circuit Infrared Temperature Sensor

52. Software Debugging

53. Circuit Testing

54. Decision Circuit

56. References [1] IEEE SoutheastCon 2012 Hardware Competition. “Release 1.0." 30 Sep. 2011. https://docs.google.com/viewer?a=v&pid=explorer&chrome=tr ue&srcid=0BwrmPsE7PwUQMThkMzk4NDUtNzAwYy00YzFjLTg1 ODMtNWJmMjg0NGVkYjM5&hl=en_US https://docs.google.com/viewer?a=v&pid=explorer&chrome=tr ue&srcid=0BwrmPsE7PwUQMThkMzk4NDUtNzAwYy00YzFjLTg1 ODMtNWJmMjg0NGVkYjM5&hl=en_US [ 2] Embedded Lab “How to measure capacitance with a microcontroller?” 5 Oct. 2011. http://embedded-lab.com/blog/?p=1747

57. SECON 2012 Midterm Presentation