RED ROVER
Team CPNE
Crossen Davis
Peter Ramer
Nancy Robinson
Eric Rodriguez
Red Rover System
Temperature
sensor
Accelerometer
LCD
Camera w/
audio
Ultrasonic
Transducer (2)
Base Station System
Power distributed to all chips
Data
Bus
Driver
CLOCK
Serial
Data
From
Computer
Vdd
Vss
8 Data
EPROM
CLK
MC68HC11
1
2 1
2
Reset
8-14 Address
Address
Bus
Driver
Reset Circuit
RAM
Address
Bus
Driver
Receiver
from
vehicle
Transmitter
to
Vehicle
Vehicle Processor System
Power distributed to all chips / Separate Power for motors
Data
Bus
Driver
CLOCK
Serial
Data
From
Computer
Vdd
Vss
8 Data
EPROM
Temperature
sensor
CLK
MC68HC11
1
2 1
2
Reset
8-14 Address
Address
Bus
Driver
Reset Circuit
RAM
Accelerometer
4
motors
decoder
H-bridge
Address
Bus
Driver
PWM
Camera w/
audio
Ultrasonic
Transducer
transmitter
LCD
Ultrasonic
Transducer
receiver
Receiver
from
Base station
Transmitter
to
Base station
M68HC11 Processor
8 bit data and 16 bit address
16 bit timer system
8 bit pulse accumulator
Real time interrupt
7 8 bit registers
Interfaces to both local and
remote peripherals
Processor circuit diagram
Reset & Voltage Regulator
Lynxmotion Robot Chassis
4
7.2V motor chassis
Room inside for additional
electronics
Can carry 5lb load
Able to stack decks on top
Low or high clearance
Decoder
Micro-Motor
Controller
1 for each motor
Micro Dual Serial Motor
Controller
m0po
m0no
m1no
m1po
Reset
SCI
Vcc
Input is made with 4 bytes of info
Start byte is most significant bit
2
+
4.7k
Motor Battery
Gnd
2 parallel Hbridges
They allow for bidirectional control of 2
motors
127 different speeds
Maximum current 2A
PWM frequency of 750Hz
Vdc
Contains
1
FPGA
4 bytes input to SCI
Motor
start byte
0x80
device
type=0x00
motor#,
direction
motor
speed
…Input to Serial Control Input
oInput of 4 bytes
o non-inverted logic
o 8 bits at a time, no start bit, 1 stop bit
o MSB read first and last bit must be clear
o To configure: need to send 3 byte packet
start byte = 0x80 change configuration = 0x02 new settings, 0x00-0x7F
bit 7 6 5 4 3 2 1 bit 0
0x x x x x x x
Bit 6: = # of motors, so in our case, =1
Bits 0-5: motor #, in our case, 1-4
After configurations set: programming protocol:
4 bytes
start byte = 0x80 device type = 0x00 motor # and direction motor speed
Bit 0: direction (1 forward, 0 backward)
Bits 1-6: motor number
Bit 7: always 0
Bit 7: always 0
Remaining: 0x00 turns off motor
0x7F turns fully on
f0 in reverse brakes
Transceiver
•433Mhz Multi-Channel RS-232 Serial RF Transceiver
•10 selectable channels
•Three baud rates: 9600, 19200, and 38400 bps
•-104dBm sensitivity
Camera and Audio
Miniature
and Lightweight
1.2 GHz
Needs 8-9V power supply
RC connection for receiver
Resolution 380 lines
Rotates w/ horizontal motor
Motor movement controlled
by PWM for slow movement
and limited angle
Connected directly to
monitor
Digital Temperature Sensor
DS18S20
Gives
9 bit centigrade temperature
Upper and lower programmable trigger
points
1-wire bus/ LSB first
-55°C to 125°C
Accuracy within .5C
Can power from data line or Vcc
Data stored in 16-bit sign-extended two’s
complement number in its own temperature
register
DS18S20
Vpu
Gnd
Vehicle
Microprocessor
4.7k
1-wire bus
DQ
Vdd
Ultrasonic 25kHz Transducers
Excited
by 25kHz square wave
Filters out signals outside 24-26kHz
band
Transmitter transducer driven by 10
cycle square waves and receiver
transducer receives echo
Timer on HC11 counts time for the
return echo
Speed of sound 1100ft/s
So object (1100 x t)ft away
Burst of sound waves to object
Vehicle
Microprocessor
Transmitter
Corresponding echo
start
Timer
Amplifier
stop
Receiver
Accelerometer Breakout
Board - ADXL E8 Series
2 axis acceleration and tilt sensor
Low power <.6mA
Direct interface to
microcontrollers via duty cycle
modulation (DCM)
Duty cycle=pulse width/period
DCM measured by counter/timer
to determine acceleration
Acceleration = (T1/T2-.5)12.5%
Vdd
T2=Rset/125Mohms
T2
LP Filters
HC11
Counter/timer
XA
YA
XP
T1
VDD
ADXL202E
YP
Vdd
GND
LCD
16x4
character display
HD44780 parallel interface
Uses HD44780U LCD Driver
LCD
Vss
Vcc
Vee
Rs
Vcc
Vehicle
Microprocessor
R/W
E
DB0-7
Software
Using Tera Term for monitor program
User interface programming in C++
Microprocessor data manipulation and peripheral interface in
assembly and C++
Considering FPGA programmed using Verilog
Done so far…
Most of the processor done and
awaiting testing.
Will be done with both processor
boards with testing by Monday
Started ordering parts
Parts list
•Base
Station Processor Board, w/
M68HC11, EPROM, RAM,,…
•Vehicle Processor Board, w/ same
components Pololu Robot Chassis
•Digital Temperature Sensor
•Accelerometer
•2 Transceivers
•Graphic LCD
•Camera w/ audio
•2 Ultrasonic Transducers
Schedule
Division of labor and
responsibilities
Crossen: Vehicle processor, Code,
Chassis & Motors, Temp Sensors
Peter: Vehicle processor, Code, LCD,
Accelerometer
Nancy: Base station, Code, Transducers,
User’s Manual
Eric: Base station, Code, Transceiver,
Video
Questions/Comments