1. 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

2. 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

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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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)
MHz
250 feet
02/13/2002
Team Epimetheus

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

16. 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

17. 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

18. 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

19. 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

20. 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