1. T EAM C ACHE M ONEY : S OLAR I NSOLATION F ORECASTING C RITICAL D ESIGN R EVIEW B. DiRenzo, L. Hager, A. Fruge, M. Dickerson, C. Duclos, N. Frank, T. Furlong

2. Outline Overview Subsystem 1: Remote Sensor Subsystem 2: Remote Power Sensor and Supply Subsystem 3: On-grid PV Sensor Subsystem 4: Server Current Status of Project Further Development Updated Division of Labor Updated Schedule

3. Power Output (W) from a PV Array on a Cloudy Day vs. a Clear Day *PV data provided by Professor Gasiewski in Boulder, CO

4. System Overview

5. Subsystem 1: Remote Sensor

6. Android Timing App Architecture: B. DiRenzo

7. Samsung Galaxy S3 - 3G HSDPA* 850 / 900 / 1900 / 2100 and 4G LTE - Accelerometer, gyro, proximity, compass, barometer sensors - A-GPS support and GLONASS - Li-Ion 2100 mAh battery - Android OS 4.1.2 - Quad Core 1.4GHz Cortex-A9 processor - 8MP camera - Micro USB port *High Speed Packet Access

8. AP003039 Wide Angle Camera Lens - 0.60X zoom factor - No perspective distortion - Easy attachment - Field of view created: Horizontal: 72 o Vertical: 51 o Diagonal: 82 o - ~ 65% increase in angle of view WRT standard lens

9. Subsystem 2: Remote Power Sensor and Supply M. Dickerson

10. Solar Panel (AB1-70) - 34.10V and 2.08A at maximum output - 70W maximum output - 1200mm x 600mm - 90% power output after 10 years - 80% power output after 25 years

11. Charge Controller (PT-12-24-5TC) - 0-45V input, 50A max input - 10-30V output depending on connections - 0-57A output, depending on power from panel - Can connect to a high voltage panel (34V) and a 12V battery - ~94% efficiency

12. Battery (PS-12350) - 12V, 35AH AGM* Sealed Lead-Acid - -4 o F (-20 o C) to 122 o F (50 o C) operating temperature range - 0.35A draw from buck converter -> capable of maintaining phone power up to 100 hours *Absorbent Glass Mat: provides up to 5x faster charging WRT flooded batteries

13. Buck Converter: 2 F F F F H Ω Ω Ω Ω V

14. LT1375 Simulation Results: Simulated with 5Ω load to simulate phone

15. LT1375 Buck Converter IC: - 500kHz, buck switching regulator - Up to 1.5A output - 25V max input voltage - High efficiency - ~350mA current draw

16. Individual Component Tolerances: - All resistors rated at 1/4W

17. Capacitor Tolerances: - 100uF tantalum capacitor rated at 10V - All other capacitors rated at 50V

18. Diode Tolerances: - 1N914 diode rated at 100V - 1N5818 Schottky diode rated at 30V

19. Power Supply Parts List - All parts are available from many manufacturers - If LT1375 is not used, basic component list will remain constant, with altered values - All parts shown to the right, except for USB cable

20. Buck Converter Results - Internal phone circuitry allows phone to charge at a voltage of 4.5-6V both safely and effectively o Due to USB "standard" of 5V + 10% (although most companies design USB outputs with 5V + 5% at most) - Graph to the right measured using oscilloscope, which seemed to introduce noise - Loaded voltage: 5.02V + 3% - When measured with multi- meter VR ≅ 0.37-0.38% ≅ - Loaded voltage: 4.97V

21. Subsystem 3: On-grid PV Sensor L. Hager

22. AS8002 Power Measurement IC -12 Bit 100kSPS ADCs - Programmable gain amplifiers - On chip voltage reference - SPI compatible interface - Fast over-current detection

23. AS8002 Pin Layout PinDescription IOP_VOPPositive current input IOM_VOMNegative current input V1PPositive voltage input V1MNegative voltage input REFPositive input reference voltage SDO (MISO)Serial Data Output (SPI) SDI (MOSI)Serial Data Input (SPI) SCLKSerial Clock (SPI) SCSB (SS)Serial Chip Select (SPI)

24. Arduino Due - 32 bit ARM processor - Up to 96MHz clock - Open source C++ based wiring language - Programmable SPI bus w/ capability of communication to multiple devices

25. Arduino WiFi Shield - Connects via 802.11 g/b networks - WEP and WPA2 encryption - Easy connection to Arduino via SPI bus - Open source firmware N. Frank

26. Subsystem 4: On-grid PV Sensor

27. Subsystem 5: Server T. Furlong

28. Subsystem 5: Server Architecture

29. TCP Socket Network - Able to receive many images simultaneously - Receives through a static IP address - Uses time taken as the image filename - Times the saving of images - Debug mode to display useful information

30. Mosaic Imaging (Stitching) Test Example An example of base images used for testing the mosaic imaging algorithm: C. Duclos

31. Mosaic Imaging (Stitching) Test Results * Average elapsed time: 5.4 seconds

32. Motion Vector Detection Test Results

33. *Average elapsed time: 1.2 seconds

34. Scale Invariant Feature Transform (SIFT) [1] SIFT Keypoint: - Circular image region described by four parameters: the keypoint center coordinates x and y, its scale (the radius of the region), and its orientation (in radians).

35. Scale Invariant Feature Transform (SIFT) [1] SIFT Detector: - Detects "blobs" by constructing a "Gaussian scale space”: a collection of images obtained by gradually reducing the image resolution ("smoothing"). - Keypoints are refined by eliminating the unstable: nearby an image edge or are found on image structures with low contrast. - Invariant to translation, rotations, and scaling of the image. SIFT Descriptor: - Characterizes the keypoint with a 3-D spatial histogram of the image gradients. The gradient at each pixel is the sample of a 3-D elementary feature vector, formed by the pixel location and the gradient orientation. Samples are weighed by the gradient norm and accumulated in a 3-D histogram (descriptor). - Used for matching of SIFT points. [1] www.vlfeat.org

36. SIFT Matching Example 1. Both mosaic imaging and motion vector detection algorithms find potential matches of SIFT keypoints (left image). 1. Then refine the matches by ranking them based on their "scores" (Euclidean distance between the two points) and finds the random sample consensus (RANSAC) throwing out the outliers (right image).

37. Current Status of Project Functioning remote power sensor: - Sending images to server Functioning On-grid PV sensor: - Communicating through SPI interface to arduino Server: - Stitching images together and outputting motion vectors Remote Power Supply: - Simultaneously charges phone and battery N. Frank

38. Further Development Remote Smartphone Sensor: - Create power saving class - Timing system development - Environmental protection Remote Power Supply: - Implement fully designed buck converter - Time permitting develop charge controller

39. Further Development Continued On-grid Sensor: - Simultaneous communication between SPI bus and Wifi shield - Fabrication of PCB Server: - Forecasting algorithm - Overlaying forecast maps on Google maps - GUI

40. Preliminary Parts List - Samsung Galaxy S3 (3) - Wide angle camera lens (3) - Arduino IOIO board (3) - Solar Panel (AB1-70) (3) - LT1375 Buck Inverter (3) - Arduino Wifi shield (3) - Arduino Due (3) - AS8002 (6)

41. Updated Division of Labor

42. Updated Schedule