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Final Presentation Group 16 Mike Orr Loc Truong Dang Khoa Le
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Mechanical Brake Camera Electronics
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Interested in robotics and wireless control To create a useful product ◦ Help the elderly and/or disabled
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Assist in day-to-day activity of user Durable ◦ Battery over-charging protection Low cost
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Weight less than 50 pounds Be able to support up to 200 pounds of weight (manual) Travel no faster than 3 miles per hour Have no more than a 2 second delay in video streaming and control Be able sustain functionality up to 40 meters away from the walker Be able to sustain functionality for up to 2 hours without recharging (non-continuous use)
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Remote Controller 2” color display DPDT Switches 2.4 GHz Video Receiver 433 MHz RF Transmitter HT12E 4 Channel Encoder Receiver
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2.4 GHz Video Transmitter 433 MHz RF Receiver HT12D 4 Channel Decoder L293D Dual H-bridge Motor Driver M1 M2 Remote Controller
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Motor Controller Left MotorRight Motor
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Using Bridge Motor Drive L293D (16 PIN chip) Cost : $2.50. Used for DC or Stepper Motor
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Forward and Backward Turning left and right
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Produce high torque Have reasonable turn speed Require 12V DC (to be compatible with system voltage supplier) Generates low current to reduce heat Low cost
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Motor Names Voltage (V) Current (A) Torque (N*m) RPMCost (USD/piece) Electric Gear Motor 123-1511.55059.99 63ZYT01C DC Motor 244.51.3280018 Leeson M1135246 120.2317.5183347
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ON/OFF switchMomentary switchLatch Switch Voltage source12 V Current rating15 A3 A Control method On - OffHold right : turn Release : stop Hold left : turn opposite direction Release : stop Press right : turn Press right : stop Press left : turn opposite direction Press left : stop
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L293D Motor Driver Electric Gear Motor(Left) Electric Gear Motor(Right)
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Motors connect to small discs. Pulleys connects to the fixed- wheels using low-tension belts. Small pins are used switch from remote control to manual use. When using remote, the pins will connect the motors to the plastic pulleys.
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ParametersTransmitterReceiver Operating Voltage3V-12V5V (±0.5V) Operating Current 40mA (12V) 9 mA (3V) 5.5mA (5V) Modulation ModeASK/OOKOOK/ASK Frequency315MHz -433.9 MHz Transmission Power25mW (315MHZ at 12V)--- Operating Range 120ft (clear of obstructions) same
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Feature: Operating voltage 2.4V-12V Built-in oscillator needs only small value external resistor Low power and high noise immunity CMOS technology Low standby current: 0.1µA (typical) at VDD=5V Capable of encoding and transmit 12 bit of information: o 8 address bits o 4 data bits Easily interface with RF Transmitter Minimal external components
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Feature: Operating voltage: 2.4V~12V Low power and high noise immunity CMOS technology Low standby current Capable of decoding 12 bits of information: o 8 address bits (binary address setting) o 4 data bits Built-in oscillator needs only 5% resistor Received codes are checked 3 times Easy interface with an RF receiver Minimal external components
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HT12D decoder will be in standby mode initially. Oscillator is disabled at this point When the decoder receive data from the encoder through the RF receiver, Din goes high and it activates the oscillator. The device starts decoding the input data, which consists of 8 address bits and 4 data bits The decoder matches the received address 3 times continuously with the local address given to pin A0 – A7. Once confirmed, the data bits are decoded and activates 4 output pins D8-D11.
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Motion L293D Output Terminals ( Motor Input Terminals) + Motor 1- Motor 1+ Motor 2- Motor 2 Forward1001 Reverse0110 Left0001 Right1000 Stop0000 Rotation of the motor changes by switching its polarity To switch/control the polarity of the motors from the remote controller, 2 DPDT switches are used
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Foscam FI9821W ◦ HD Quality, 1280x 720 Resolution ◦ High Cost TENVIS JPT3815W ◦ Lesser Quality ◦ Good Pricing Q-SEE Security Camera ◦ Good Quality ◦ RCA Compatible ◦ Free of Charge (Loc)
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2.4 GHz Wireless Video/Audio Module ◦ 9 Volts ◦ Max Current: 180mA (Receiver) 30mA (Transmitter) ◦ Frequency: 2.4 GHz ◦ RCA Connectors
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UA7805 Regulator 9V Battery Remote Controller Block Diagram Power Control Video DPDT Switches 2.4 GHz Video Receiver 433 MHz RF Transmitter HT12E 4 Channel Encoder 2” color display
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12V Battery Receiver Block Diagram Regulator (5V) Power Control Video 2.4 GHz Video Transmitter 433 MHz RF Receiver HT12D 4 Channel Decoder L293D Dual H-bridge Motor Driver M1 M2
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3 options: ◦ HitLights Rechargeable 3800mAh Lithium Ion Battery Pack ◦ Pitsco TETRIX 12-Volt Rechargeable NiMH Battery Pack and Charger ◦ NiMH Battery Pack: Customize 12V 5000mAh
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μA7805CKC ◦ Internal Thermal-Overload Protection ◦ High Power-Dissipation Capability LM7809 ◦ Short Circuit Protection ◦ Thermal Overload Protection
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DeviceVoltage (V)Current (mA)Power (mW) HT12E5525 HT12D5525 RF Receiver5525 RF Transmitter5525 L293D (1) - chip50.10.5 L293D (2) - chip50.10.5 Left Motor12240028800 Right Motor12240028800 Video Transmitter930270 Video Receiver930270 Camera126007200 Video Display92161944 Total Power:67.385 Watts
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3800 ---------------------------- 5696.2 0.467 Hours* *calculated for all components running constantly at maximum ratings
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Power ◦ Constant running motor ◦ Varying on/off Max Weight Supported ◦ Driving – 25 pounds ◦ Stationary – 200 pounds Speed (Max vs Avg) ◦ Max < 3 MPH ◦ Avg = 0.77 MPH Video – tested at subsystem level
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Thermal Issues ◦ Motor Driver reaching thermal threshold Use 12V relays to drive motors Mechanical Issues ◦ Platform causes stability issues ◦ Wheel drive limits weight support capability Redo platform Antenna ◦ Limits transmission range Need longer antenna
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ItemUnit PriceOrderedPrice Video Transmitter/Receiver$32.001 RF Transmitter/Receiver$4.121 HT12D/HT12E 1$0.00 UA7805CKCS$0.491 LM7809$0.671 Pitsco TETRIX 12-Volt Rechargeable NiMH Battery Pack and Charger$84.901 Video Display$42.311 22 pF capacitor (30pk)$2.431 QSEE Security CameraFREE1$0.00 Wondermotor 12V DC Gear Motor$59.992$119.98 L293D$2.502$5.00 DPDT Switches$5.002$10.00 PCB$48.362$96.72 Miscellaneous (bolts, screws, welding etc)$100.001 Total $498.62
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