ECE 477 Design Review Team 07  Fall 2009

1. ECE 477 Design Review Team 07  Fall 2009 Eric Glover Shaun Greene Steve Andre Russell Willmot POV Machine

2. Outline • Project overview • Project-specific success criteria • Block diagram • Component selection rationale • Packaging design • Schematic and theory of operation • PCB layout • Software design/development status • Project completion timeline • Questions / discussion

3. Project Overview • Persistence of Vision (POV) machine that will control a single column of rotating LEDs to project a pattern to the user • 96x32 pixel 3-bit color output • Display in 360° with 10° resolution • Track an RF beacon • Example output patterns are a clock and thermometer, a small image, or other text

4. Project-Specific Success Criteria • The ability to display a pattern with rotating LEDs • The ability to control the direction in which a pattern is projected • The ability to track the angle of arrival of an RF beacon • The ability to update a projected image while the machine is in operation • The ability to accept user-generated input to change display

5. Block Diagram Lower Board

6. Block Diagram Upper Board

7. Assumed: 1800 RPM speed 15 cm radius disc (center to LED post) 180° display 96x32 RGB pixel display RF transceiver is 1Mbps (SPI) Minimum voltage difference of phase detector = 0.014 V for a 10° angle change Results 33 ms per revolution 174 μs per column (96 bits per column) Image data rate = 552 kbps (SPI) 92.6 μs = 1° of rotation Image = 9216 bits Time to transfer image = 10ms (ideal) 3.3V ATD resolution min = 8 bit (0.013 V resolution) Component Selection Rationale

8. Micro #2 SPI (2 channel) 552 kbps & 1Mbps 16 I/O External Interrupt Timer Pulse Accumulator 8 KB of Flash 6 KB of SRAM 3.3 V preferred Component Selection Rationale Micro #1 • A/D (3 channels), at least 8 bit • SPI (1 channel) 1 Mbps • At least 21 I/O pins • 36 KB of SRAM • 36 KB of Flash to store images • 3.3 V preferred

9. Component Selection Rationale Micro #1 Micro #2 • PIC24FJ32GA002 Microcontroller • 32 MHz Clock w/PLL • 16-bit Architecture • 8 MHz SPI (2 channels) • 21 I/O pins available • 32 KB of Flash • 8 KB of SRAM • 3.3 Volt supply • 28 pin SOIC • C Compiler Optimized Instruction Set • Extra Features: • Not a whole lot ARM Cortex M3 LM3S8962 Microcontroller • 50 MHz Clock w/PLL • 32-bit Architecture • 4 A/D channels (10 bit) • 24 MHz SPI • 37 I/O pins available • 256 KB of Flash • 64 KB of SRAM • 3.3 Volt supply • 100 pin LQFP Extra Features: • Integrated support for graphic OLED screen • Programmable with LabVIEW for ARM • Integrated Micro SD card drivers and hardware • Direct connection to Ethernet port • Free!!!

10. Packaging Design

11. Packaging Design

12. Packaging Design

13. Packaging Design

14. Schematic/Theory of Operation • Main Power Supplies • Lower Board To Slip Ring 3.3V LDO 5V Buck converter Rectifier & Filter

15. Schematic/Theory of Operation • Slip Ring – Power transfer from stationary PCB to rotating PCB • Uses carbon brushes against rotating brass rings to transmit power • 2.8 Vrms noise @ 30 Hz worst case • 0.7 Vrms noise @ 30 Hz best case

16. Schematic/Theory of Operation • Main Power Supplies • Upper Board Power Input & Filter 5 V 3.0 Amp buck converter 3.3V LDO

17. Schematic/Theory of Operation • Upper Board Microcontroller (PIC24F)

18. Schematic/Theory of Operation • Infrared Red Emitter/Detector

19. Schematic/Theory of Operation • LED Driver and LED connections

20. Schematic/Theory of Operation

21. Schematic/Theory of Operation • RF Transceivers: • Wireless communication • 2.4 GHz band • SPI Interface • 1 Mbps data rate

22. Schematic/Theory of Operation • User Location Detection: Amplifier 1.2 GHz Oscillator Handheld Transmitter

23. Schematic/Theory of Operation • User Location Detection:

24. Schematic/Theory of Operation • User Location Detection: RF Connector Phase Detector/Comparator 1.2 GHz Bandpass Filter

25. PCB Layout • Four PCB Segments • Lower Board (motor power circuitry, 1.2 GHz RF circuit, power supply) • Upper Board (power circuitry, PIC microcontroller) • LED Post (RGB LEDs and LED drivers) • Transmitter (oscillator, antenna)

26. PCB Layout • Lower Board 4.7”x4.7”

27. PCB Layout • Upper Board 3.7”x3.0”

28. PCB Layout • LED Post 5.3”x2.0”

29. PCB Layout • Transmitter 2.0”x2.0”

30. Software Design/Development Status • Stationary Micro Software Functions • Control OLED screen and accept input from pushbuttons • Allow user to navigate a menu and select options • Read analog phase detection and temperature data • Generate new pixel maps • Send pixel map data to upper micro

31. Software Design/Development Status • Upper Micro Software Functions • Use external interrupt to determine “0°” • Use IR pulses and timer to calculate rotational speed and stability • Read and store data from RF transceiver • Shift data out to the LED drivers at precise times

32. Software Design/Development Status • Lower Microcontroller • User interface started and minimally working • The rest is in progress • Upper Microcontroller • Have PIC24F development board and all software in progress • No milestones yet

33. Project Completion Timeline • Week 9 – Finish final schematic PCB and proof of parts • Week 10 – Finish software architecture and flow • Week 11 – Test software, build packaging and start soldering • Week 12 – Continue soldering and testing PCB • Week 13 – Complete software, start packaging & debugging • Week 14 – Continue construction and debugging • Week 15 - Finish debugging and add final tweaks • Week 16 – Demonstrate a complete working project

34. Questions / Discussion