PC Controlled RC Car

1. PC Controlled RC Car Group 19 Deniz Kilic & Juan M. Navarro ECE 445 Senior Design April 25, 2007

2. Introduction • Build PC Controlled RC Car • Blends Wireless Communications • Remote Sensing Mechanisms • Security Applications • Develop Serial Port Interface • Control RF transmitters from PC • Send signals to RC car

3. Benefits • Allows users to monitor their home remotely • Serves as security vigilante for various applications • Virtual watch-dog • Appealing toy for all ages!

4. Features • Radio Controlled • On-board Wireless Camera • Proximity Sensor • Precision Steering • Remote Login Capability • Camera Turret

5. PC Controlled RC Car

6. Design Overview

7. PC Connections Schematic

8. Hardware X10 Wireless Camera • 12V DC input • Frequency of 2.4 Hz • Transmits signal to receiver connected to PC

9. Hardware Sabrent Tuner Video Capture Box • Converts video signals • USB connection directs video signal to a PC • Input from the X10 Wireless Camera Receiver • Video signals will be fed into GUI that will allow the user to see what X10 Wireless Camera records

10. Hardware • Hardware Interface to the local PC • USB connection to capture the video signals arriving at the X10 Wireless Camera Receiver • Serial Interface connection sends information to the transmitter Computer Output Panel

11. Hardware Linx Transmitter • TXM-900-HP3-PPS • Receives data from the serial port of the PC

12. Software Overview Graphical User Interface on Host PC • Video Capture • Mouse Controller

13. Graphical User Interface

14. Software Design Mouse Controller • Main control mechanism • Moving the mouse cursor around the Cartesian plane results in a vector whose starting point is the center and whose tip will be the mouse pointer • Magnitude proportional to the speed of the vehicle • Angle proportional to the direction on the RC Car steering

15. Transmitter Software • Interrupt-driven • Multi-threaded program • Processes mouse motions/left and right key presses • Left or right mouse keys control the direction the camera turret servo will spin • Exit when the user presses ESC or closes the program down

16. RC Car Connections Schematic

17. Hardware • RXM-900-HP3-PPS • Receives asynchronous data from RF Transmitter • Sends data to microprocessor Linx Receiver

18. Hardware Servo Motors • 2 servo motors • Allows camera turret to rotate 360 degrees • Controls the steering mechanism in the RC Car frame

19. Hardware DC-to-DC Converter • Input ranges from 8V DC to 32V DC • Output of 24V DC • Rated Output Current of 130 mA • Output Power of 3 Watts • Steps up the voltage from 7.2V DC

20. Hardware Relays • Separates the low voltage/current TTL logic signals of the PIC from the higher voltage/current signals of the motor • Powers drive train motor • Controls the direction of drive train motor spins

21. Hardware • Voltage Regulator • Provides Steady 5V DC Output • Rated for 1.2 A Maximum • Current Amplifier • Reduces Strain on PIC • Draws Less Current from PIC

22. Hardware Microprocessor • Main control center for our RC Car • Reads incoming signals • Outputs control signals • Processes closed-loop feedback signals without user interaction

23. Hardware Fuses • 4A fuse protects our RC Car motor circuit • 300 mA fuses protect our TTL logic lines Crystal Oscillator • Provides a square wave clock signal • Frequency of 20 MHz • Maximum input current of 17 mA

24. Hardware MAX 232 Chip • Dual driver/receiver • Single power supply • Connects to the microcontroller to generate proper voltages • RS232 & TTL converter

25. Hardware IR Proximity Sensor • Provides an analog output voltage proportional to the distance of the object it senses • Detecting range is between 4 cm and 30 cm • Output voltage between 0V and 3.2V DC • Input Rating: 7V DC at 50 mA of current

26. Receiver Software • Executed procedurally • Checks the proximity sensor • Controls the direction of RC Car • Controls camera turret in a certain direction • Exit when the system is shut down or runs out of power

27. IR Proximity Sensor Test

28. Analog-to-Digital Converter Test

29. IR Sensor Control Logic • 60 is approximately 12 cm which is 1.1 V. if(value < 60) { if(input(PIN_B1) == 1) { printf("Main Power Relay is ON. Value = %d\n“, value); delay_ms(2000); } output_high(PIN_C1); // main on/off relay, pin #16 } else { if(input(PIN_B1) == 1) { printf("Main Power Relay is OFF.\n"); delay_ms(2000); } output_low(PIN_C1); // main on/off relay, pin #16 }

30. Transmitter/Receiver Test Duty Cycle: 25% Frequency: 100 Hz Period: 0.01 sec

31. PWM Output Test Duty Cycle: 12.2% Frequency: 1220 Hz Period: 819.67 usec

32. Successes • Communication from PIC to PC • Proximity Sensor • Steering Controls • Camera Turret • Linx Transmitter/Receiver Communication • Control Relays

33. Challenges • Communication from PC to PIC • Servo Torque • Sound Sensor Sensitivity • PWM Control from PIC • Integrated Graphical User Interface • DC-to-DC Converter

34. Recommendations • Higher Torque Servos • Sensitive Sound Sensors • Avoid Mechanical Relays for PWM • Use Interrupts for PWM

35. Questions?

36. Special Thanks… Professor Swenson Hyesun Park Alex Spektor Jon Weber ECE Parts Shop ECE Department