Download Team Epimetheus Wireless Robot Module

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
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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.
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Team Epimetheus
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Platform Specification
• Wireless sensor module is to collect data
from the OSU-FIRST robot
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Team Epimetheus
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Block diagram
Sensor Array
Analog /
Digital
Conversion
Power
Management
Wireless
Communication
Interface
Host MCU
User Interface
/ Receiver /
Video Capture
X10 Video
System
= Power Lines
= Data Lines
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Team Epimetheus
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Matrix Management
Host
MCU
Power
Sensors Wireless User Int.
P
Matt Beerman
John Fatica
P
P
P
Hubert Ho
Erik Justen
S
Brad Kramer
P
Matt Rankin
Carl Yehman
P
P
S
P
P = Primary Lead
02/13/2002
Video
Team Epimetheus
S = Secondary
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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
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Team Epimetheus
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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.
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Team Epimetheus
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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
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Team Epimetheus
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Micro-Controller Unit
Code Overview
Main Routine
Data Test Routine
Start
RPM
Valid?
Initialize
PIC
NO
Flag RPM bit
in TX Packet
NO
Flag BATT bit
in TX Packet
YES
Read/Store
ADC Data
BATT
Valid?
Data Test
Routine
Transmit
Data
02/13/2002
Generate 16-bit
Checksum
Team Epimetheus
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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
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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
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Team Epimetheus
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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
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Team Epimetheus
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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
02/13/2002
Team Epimetheus
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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
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Wireless Communication
• Packet Definition
SYNC BYTES
(4 BYTES)
5A5AA5A5
02/13/2002
PACKET INFO
(1 BYTE)
DATA
(16 BYTE)
Team Epimetheus
CHKSUM
(2 BYTE)
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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
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Team Epimetheus
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Program Flow
• Wireless Serial Data to
Server Daemon
• Daemon network Thread
passes info to Applet
• Multiple graphics threads
update applet
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User Interface
GUI
• Java Applet
• Displays Values and Graphs • RPM Wheel Data (2)
• Temperature Data (2)
• Motor Current Data (2)
• Battery Current Data
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Team Epimetheus
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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
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Team Epimetheus
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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
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