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

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. 02/13/2002 Team Epimetheus

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

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

Matrix Management P S Host MCU Power Sensors Wireless User Int. Video Matt Beerman P John Fatica Hubert Ho Erik Justen S Brad Kramer Matt Rankin Carl Yehman P = Primary Lead S = Secondary 02/13/2002 Team Epimetheus

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 02/13/2002 Team Epimetheus

Micro-Controller Unit 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. 02/13/2002 Team Epimetheus

Micro-Controller Unit 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 02/13/2002 Team Epimetheus

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

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

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

Sensors RPM Sensor (2) Purpose RPM Sensor Components 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 02/13/2002 Team Epimetheus

Sensors Temperature Sensor (2) Current Sensors (3) 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 02/13/2002 Team Epimetheus

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 02/13/2002 Team Epimetheus

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

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 02/13/2002 Team Epimetheus

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

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

Proposed Schedule W1 W2 W3 W4 W5 W6 W7 W8 W9 Schematic / Algorithm Dev. Parts Acquisition Build/Test Host MCU Power Sensors Wireless / Communications User Interface Video System Integration 02/13/2002 Team Epimetheus

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 02/13/2002 Team Epimetheus