1. 02/13/2002Team Epimetheus1 Team Epimetheus Wireless Robot Module Matt Beerman John Fatica Hubert Ho Erik Justen Brad Kramer Matt Rankin Karl Yeh EE682 Dr. Steven Bibyk

2. 02/13/2002Team Epimetheus2 Objective To build a wireless sensor module using the robot platform. To gain knowledge and experience for future projects and presentations. To have a technical understanding of projects and designs.

3. 02/13/2002Team Epimetheus3 Platform Specification Wireless sensor module is to collect data from the OSU-FIRST robot

4. 02/13/2002Team Epimetheus4 Block diagram Sensor Array Host MCU Power Management Wireless Communication Interface X10 Video System User Interface / Receiver / Video Capture Analog / Digital Conversion = Power Lines = Data Lines

5. 02/13/2002Team Epimetheus5 Matrix Management Host MCU PowerSensorsWirelessUser Int.Video Matt Beerman P John Fatica PP Hubert Ho P Erik Justen SP Brad Kramer P Matt Rankin PS Carl Yehman P P = Primary LeadS = Secondary

6. 02/13/2002Team Epimetheus6 Micro-Controller Unit Microchip PIC (16F877) –Programmed in assembly using MPLAB –4 MHz Clock Speed –Built-in Synchronous Serial Port (SSP) and Universal Synchronous/Asynchronous Receiver/Transmitter (USART) –8K of FLASH program memory; 368 bytes data memory

7. 02/13/2002Team Epimetheus7 PIC communication with A/D –PIC to MAXIM A/D communication performed using Serial Peripheral Interface (SPI) compatible bus through SSP module. –PIC acts as the master and generates the clock at a rate of Fosc/4. –Data is simultaneously clocked in/out of SSP buffer. –RPM and Battery Voltage data checked on-board the PIC for validity. Micro-Controller Unit

8. 02/13/2002Team Epimetheus8 PIC Communication with PC –Standard RS232 serial link –Take advantage of built in USART on PIC PIC hardware handles construction/transmission of each byte and baud rate timing issues Achieve transmit speeds up to 19200bps Too much error in baud rate calculation past 19200 –Assemble 23 byte data packet and send Micro-Controller Unit

9. 02/13/2002Team Epimetheus9 Micro-Controller Unit Code Overview Start Initialize PIC Read/Store ADC Data Data Test Routine Transmit Data Main RoutineData Test Routine RPM Valid? Flag RPM bit in TX Packet Flag BATT bit in TX Packet BATT Valid? NO YES Generate 16-bit Checksum

10. 02/13/2002Team Epimetheus10 Power Management Power Supply –12 volt lead acid battery +/-12v, +/-10v, +6v, +/-5v –3 adjustable regulators National Semiconductor LM2991 LM2941

11. 02/13/2002Team Epimetheus11 Power Management Management –Monitoring of voltage levels in the battery –Auto shutdown of the video 2941 2991 12 V +12 +10 +6 +5 GND -5 -10 -12 10Ω/5W = Resistor

12. 02/13/2002Team Epimetheus12 Sensors RPM Sensor (2) –Purpose Will be used to count the number of rotations of a particular wheel in order to approximately determine the velocity of the robot. –RPM Sensor Components A pinwheel with alternating reflective and non-reflective surfaces. An Omron reflective sensor (continuous beam) A 8-bit binary counter (TI SN74HC590A) A 8-bit DAC (National DAC0808) An Op-amp

13. 02/13/2002Team Epimetheus13 Sensors Temperature Sensor (2) –Thermometrics NTC Thermistor Epoxy coated solid state sensor Suitable for PCB and probe mountings Current Sensors (3) –One 100 amp sensor for battery current F.W. Bell BB-100 Hall effect current sensor –Two 25 amp sensors for motor current Amploc Amp25 current sensor

14. 02/13/2002Team Epimetheus14 Wireless Communication Requirements –Send data and video from sensor module to User Interface computer –Transmit data up to 100 meters Solution –Wireless Serial link –Parallax RF product (27987, 27986) 433.92 MHz 250 feet

15. 02/13/2002Team Epimetheus15 Wireless Communication Packet Definition SYNC BYTES (4 BYTES) 5A5AA5A5 PACKET INFO (1 BYTE) DATA (16 BYTE) CHKSUM (2 BYTE)

16. 02/13/2002Team Epimetheus16 Server Daemon Utilizes java packages –javax.comm –java.net –Cross-platform Threads used for opening new network sockets Formats serial data for passing to applet

17. 02/13/2002Team Epimetheus17 Program Flow Wireless Serial Data to Server Daemon Daemon network Thread passes info to Applet Multiple graphics threads update applet

18. 02/13/2002Team Epimetheus18 User Interface GUI Java Applet Displays Values and Graphs - RPM Wheel Data (2) Temperature Data (2) Motor Current Data (2) Battery Current Data

19. 02/13/2002Team Epimetheus19 Proposed Schedule W1W2W3W4W5W6W7W8W9 Schematic / Algorithm Dev. Parts Acquisition Build/Test Host MCU Power Sensors Wireless / Communications User Interface Video System Integration

20. 02/13/2002Team Epimetheus20 Moving Forward Continue parts acquisition Re-acquire PIC Once parts are in: – Continue sensor work – Continue UI integration – Add in wireless comm. – Test and debug Time permitting, incorporate video