RED ROVER

1
RED ROVER

• Team CPNE
• Crossen Davis
• Peter Ramer
• Nancy Robinson
• Eric Rodriguez

2
Red Rover System
Accelerometer
Temperature sensor
LCD
Camera w/ audio
Ultrasonic Transducer (2)
3
Base Station System
Power distributed to all chips
Data Bus Driver
EPROM
MC68HC11
CLOCK
8 Data
Vdd
Vss
Serial Data From Computer
CLK
Address Bus Driver
Reset
RAM
8-14 Address
Reset Circuit
Address Bus Driver
Transmitter to Vehicle
Receiver from vehicle
4
Vehicle Processor System
Power distributed to all chips / Separate Power
for motors
Data Bus Driver
EPROM
MC68HC11
CLOCK
8 Data
Vdd
Vss
Serial Data From Computer
Temperature sensor
CLK
Address Bus Driver
Reset
RAM
8-14 Address
Reset Circuit
Accelerometer
decoder
4 motors
Address Bus Driver
H-bridge
PWM
Transmitter to Base station
Receiver from Base station
LCD
Ultrasonic Transducerreceiver
Ultrasonic Transducer transmitter
Camera w/ audio
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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

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Processor circuit diagram
7
Reset Voltage Regulator
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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
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Micro Dual Serial Motor Controller

• Contains 2 parallel H-bridges
• They allow for bi-directional control of 2 motors
• 127 different speeds
• Maximum current 2A
• PWM frequency of 750Hz

• Input is made with 4 bytes of info
• Start byte is most significant bit

4 bytes input to SCI
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Input to Serial Control Input

• Input of 4 bytes
• non-inverted logic
• 8 bits at a time, no start bit, 1 stop bit
• MSB read first and last bit must be clear
• To configure need to send 3 byte packet

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
Bit 7 always 0 Remaining 0x00 turns off motor
0x7F turns fully on
f0 in reverse brakes
Bit 0 direction (1 forward, 0 backward) Bits
1-6 motor number Bit 7 always 0
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Transceiver

• 433Mhz Multi-Channel RS-232 Serial RF Transceiver
• 10 selectable channels
• Three baud rates 9600, 19200, and 38400 bps
• -104dBm sensitivity

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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

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Digital Temperature SensorDS18S20

• Gives 9 bit centigrade temperature
• Upper and lower programmable trigger points
• 1-wire bus/ LSB first
• -55C to 125C
• Accuracy within .5C
• Can power from data line or Vcc
• Data stored in 16-bit sign-extended twos
  complement number in its own temperature register

DS18S20 Gnd DQ Vdd
Vpu
Vehicle Microprocessor
4.7k
1-wire bus
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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

Vehicle Microprocessor
Burst of sound waves to object
Transmitter
Corresponding echo
start
Timer
Receiver
Amplifier
stop
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Accelerometer Breakout Board - ADXL E8 Series

• 2 axis acceleration and tilt sensor
• Low power lt.6mA
• Direct interface to microcontrollers via duty
  cycle modulation (DCM)
• Duty cyclepulse width/period
• DCM measured by counter/timer to determine
  acceleration
• Acceleration (T1/T2-.5)12.5

Vdd
ADXL202E
VDD
Vdd
T2Rset/125Mohms
XA
LP Filters
HC11 Counter/timer
GND
YA
T2
XP
YP
T1
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LCD

• 16x4 character display
• HD44780 parallel interface
• Uses HD44780U LCD Driver

Vehicle Microprocessor
LCD
Vss
Vcc
Vee
Rs
R/W
E
DB0-7
Vcc
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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
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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

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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

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Schedule
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Division of labor and responsibilities

• Crossen Vehicle processor, Code, Chassis
  Motors, Temp Sensors
• Peter Vehicle processor, Code, LCD,
  Accelerometer
• Nancy Base station, Code, Transducers, Users
  Manual
• Eric Base station, Code, Transceiver, Video

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• Questions/Comments