RED ROVER Team CPNE Crossen Davis Peter Ramer Nancy Robinson Eric Rodriguez

Red Rover System Camera w/ audio Temperature sensor Ultrasonic Transducer (2) Accelerometer LCD

Base Station System MC68HC11 CLOCK Address Bus Driver Address Bus Driver Reset Circuit Data Bus Driver RAM EPROM Serial Data From Computer Transmitter to Vehicle Receiver from vehicle Reset Power distributed to all chips CLK 8 Data 8-14 Address VddVss

Vehicle Processor System MC68HC11 CLOCK Address Bus Driver Address Bus Driver Reset Circuit Data Bus Driver RAM EPROM decoder Serial Data From Computer Transmitter to Base station Receiver from Base station Reset Power distributed to all chips / Separate Power for motors CLK 8 Data 8-14 Address VddVss Camera w/ audio Temperature sensor Accelerometer LCD Ultrasonic Transducer receiver Ultrasonic Transducer transmitter 4 motors PWM H-bridge

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 Micro-Motor Controller Decoder 1 for each motor

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

…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 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 0: direction (1 forward, 0 backward) Bits 1-6: motor number 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 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 Vehicle Microprocessor DS18S20 Gnd DQ Vdd 1-wire bus Vpu 4.7k

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 Receiver Transmitter Burst of sound waves to object Corresponding echo Timer start stop Amplifier

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% T2 T1 T2=Rset/125Mohms HC11 Counter/timer ADXL202E YP XP GND VDD YA XA Vdd LP Filters

LCD  16x4 character display  HD44780 parallel interface  Uses HD44780U LCD Driver VssVccVeeRsR/WEDB0-7 LCD Vcc Vehicle Microprocessor

Software Microprocessor data manipulation and peripheral interface in assembly and C++ User interface programming in C++ Using Tera Term for monitor program 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: V ehicle processor, Code, Chassis & Motors, Temp Sensors  Peter: V ehicle processor, Code, LCD, Accelerometer  Nancy: Base station, Code, Transducers, User’s Manual  Eric: Base station, Code, Transceiver, Video

Questions/Comments