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Team Ninja. Introduction/Overview. Implementation of Subsystems MCU board Chassis/Motor/Motor Driver Sensor Parts List Schedule Division of Labor. MCU Board. MCU Board Block Diagram. MCU Pinout. MC68711K4 Microprocessor. Features 8-bit opcodes and data 16-bit addressing
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Introduction/Overview • Implementation of Subsystems • MCU board • Chassis/Motor/Motor Driver • Sensor • Parts List • Schedule • Division of Labor
MC68711K4 Microprocessor • Features • 8-bit opcodes and data • 16-bit addressing • 8 A/D Converters • 4 PWM signal generators • Non-multiplexed address and data lines
XC95108 CPLD • Implementation • Chip select device • All other on board logic • CPLD vs FPGA • Simpler
ECS-2200B Clock • Clock for the microprocessor • 8 MHz speed
Reset Button • Input that resets our microprocessor • Inverters de-bounce signal
AT29C256 EPROM • Features • Fast read access time –70ns • Fast program time • 64 byte program time –10 ms • Chip erase time – 10 ms • Typical Endurance > 10,000 cycles
Samsung 428 SRAM • Features • Organization 32K x 8 • Low Data Retention Voltage
Power System • MC7805 Voltage Regulator • Outputs Steady 5V • Large Input Voltage Range (7.5V – 18V) • Power Busses • Bypass Capacitors (0.1uF)
Infrared Sensors • Using Sharp GP2D120 IR sensors • Max of 8 sensors (high cost) • Above, below, and forward sensors • Analog Output • Consistent voltage curve vs distance • Low power consumption • 150 mW / sensor max
IR Sensor limitations • High Cost per unit ($15) • Unfeasible to be covered on all sides • Need to ensure unit always “looks forward” before driving • Up to 8 sensors on front side • Positioned to see: • Directly forward • 45 deg angle upward of directly forward • 45 deg angle below directly forward
Infrared SensorsOutput Characteristic 0-15 cm to right 0-50cm below
A/D Conversion • HC711K4 provides 8 multiplexed inputs to an A/D converter • Continuously sample inputs • IR sensor directly connected to multiplexed MCU input
A/D Conversion • Provides 8 bits of resolution • Output of A/D converter is $00-$FF stored in register • VRH controls maximum voltage seen • Will use VRH = 3.0 V • Sampled Voltage > VRH • Data stored = $FF • VRL controls minimum voltage seen • Will use VRL = 0.8 V • Sampled Voltage < VRL • Data stored = $00 • Linearly scaled in between $00 - $FF • 8.5 mV resolution using above VRH and VRL
A/D Reconstruction • Convert Voltage-Distance table to $00-$FF format for easy lookup • $00 = 15 cm…$01 = 15 cm…$FE = 3cm…$FF = 3cm • Constraint: Need to know how close to wall start position is • Fix: always start more than 5cm away from wall
A/D Reconstruction7-Segment LED • 7-segment LED displays current position • 1 display per sensor • Hex display • 3-9 cm displayed as 3-9 • 10-15 cm displayed as A – F • Assistance in debugging movement • Why did it turn when it wasn’t even near a wall?
A/D Reconstruction7-Segment LED Implementation • Encode distance measurement into signal displayable by 7-segment LED • Write result to $2000-$2FFF • Reserved for LED latches by CS CPLD • Latch this data using 8-bit latch • Connect to display with pull-up resistors • 3-F displayed on 7-segment LED
Battery PowerConstraints • MCU board requirements: • 8V - 30V • Voltage regulator limits to 5V, 1A • Max of 1000mAh • Motor requirements: • 2000mAh / motor • Step-up voltage to ~10V • Monitor battery charge to prevent going below 10% charge
Battery PowerSolution: Tether • 5000mAh batteries expensive, heavy, and/or difficult to recharge • Tethered approach 1 or 2 cables attached to exterior power supply • Too complicated to complete on time • Focus of project: intelligent movement of device
Programming:Overview Always No objects detected Move Forward IR Check Object detected Check for obstacle Turn, Change Direction
Programming:Moving Forward No Object Detected Set internal Latch Move Forward Always Moving N/S Turn On PWM Both Motor Driver Count Steps N/S Moving E/W PWM ~200Hz Step the Motor Count Steps E/W
Programming: IR Check Always IR sensor’s A/D conversion Result register Initialize A/D Compare to Voltage- Distance table Distance Estimation Calculation 7-seg LED latch Threshold i.e. 4 cm 7-seg LED Objected Detected? Object Detected No Object Detected
Programming:Turning(Always Turn Left) Object detected (straight ahead) Set R wheel latch R wheel forward R Wheel Motor Driver Check for obstacle PWM ~200 Hz Done Turning L Wheel Motor Driver Clear L wheel latch L wheel backward Rotate Direction 45deg
STP-MTR-17048 Bipolar Motor • Stepper Motor • 1.8 degrees/step • Lightweight • 6.0 lbs Maximum Load • 2.0A Rated Current • 0.59Nm Maximum Holding Torque • Motor/Driver Works Best Above 200Hz • Motor Needs at Least 16W of Power
Bipolar Stepper Motor Driver • One Driver for Each Stepper Motor • Powered at 8-30V • Direction • Step • Optoisolation • Dual H-Bridge
Chassis Assembly • 1.65ft Diameter • Round • Plexiglas • Swivel Wheels
Vacuum • 14.4 V • 30 Watts • 7.2V Rechargeable Battery
Parts List • STP-MTR-17048 Bipolar Motors (2) • Quasar 3158 Bipolar Stepper Motor Driver (2) • 3”x13/16” Wheels (2) • Swivel Wheels (2) • Sensors (8) • Plexiglas Chassis • HC711K4 Microprocessor • XC95108 CPLD • ECS-2200B Clock • AT29C256 ROM • Samsung K6x0808C1D-DF70 RAM • MC7805 Voltage Regulator • 7-Segment LEDs (8) • Vacuum (Black and Decker Cyclone)
Status • Connects Motor With U-Bolts • Done With Chassis Assembly • Done With Sensors • MCU Board connected and running • CPLD Programmed • Processor Resetting Correctly • ROM connected
Plan of Attack • Milestone 1 • MCU board completely done • Sensor input to MCU • MCU output to motor drivers • Basic vehicle movement • Milestone 2 • Intelligent movement based on sensor input • Integration of vacuum • User interface
Division of Labor • Kevin • Microcontroller Programming • MCU board • Communication Between Devices • Tim • Peripheral Sensors • MCU board • Sensor Logic • Simone • Mobility Functions • Chassis • Mobility Logic • Track Distance/Make Internal Map • Vacuum Integration
Conclusion • Implementation of Subsystems • MCU board • Chassis/Motor/Motor Driver • Sensor • Parts List • Schedule • Division of Labor
Questions? • Simone.Shen@gmail.com • Timothy.Palagi@gmail.com • Kevin.Riegner@gmail.com