James Crosetto BS (Computer Science and Computer Engineering) Jeremy Ellison BS (Computer Science and Computer Engineering) Seth Schwiethale BS (Computer Science)

 project objectives  requirements/specifications  design issues/technology

 expanding the range of a remote control car  control car over network, similar to a printer  be able to have first person view of car’s location

 establish connection between rc car and driver’s computer  get real time visual feed  control rc car  user friendly GUI  backtracking (retracing to reacquire lost signal)

 between rc car and user’s computer  TCP/IP protocol suite ◦ connection oriented ◦ reliable  sockets ◦ what are they?

 IP camera ◦ video stream ◦ wireless interface ◦ linux kernel  Axis® RTSP ◦ control protocol for media server ◦ “play” and “pause” type of commands ◦ control of media stream properties (bit rate, res, etc…)

 Power: 5.1 V DC, max 3.5 W  Alarm output (motion, audio, external)  Open API for software integration  CPU, video processing and compression; ◦ Ram: 32 MB ◦ Flash: 8 MB IP Camera

tcp/ip

 commands sent from user’s computer to camera  camera relays signal to microprocessor  microprocessor sends translated signal to car

 single connection  server on camera – C  client on user’s computer – Java

 create socket int socket_descriptor; socket_descriptor = socket(AF_INTET, SOCK_STREAM, 0);//domain, type, protocol) //0 = IPPROTO_TCP for AF_INET, SOCK_STREAM  bind socket to port struct sockaddr_in address; address.sin_family = AF_INET; address.sin_addr.s_addr = INADDR_ANY; address.sin_port = htons(7000); bind(socket_descriptor, (struct sockaddr *)&address, sizeof(address));  listen for connections listen(socket_descriptor, 5) //there can be up to 5 connections pending, >5 timeout error  accept connection int addrlen; struct sockaddr_in address; addrlen = sizeof(struct sockaddr_in); new_socket = accept(sock_descriptor, (struct sockaddr *)&address, &addrlen); if(new_socket<0) perror(“Accept connection”);

 3 Leads: ◦ Ground ◦ V cc ◦ Pulse width modulation

 Square Pulse wave of ms repeats every ~20ms  Width of pulse determines the position of the servo with 1.5ms as the normal center  The amplitude of the pulse is from the reference level to the V cc  V cc = V

 4-pin I/O terminal ◦ 1 transistor output  Max load of 100mA  Max voltage of 24V DC ◦ 1 digital input  Can be activated or left floating ◦ Auxiliary power and GND  Max 5V DC, 2.5W  Connector for main power  Power to auxiliary equip, Max 50mA

tcp/ip

 Receives signals from the transistor output of the IP camera  Translates the signals  Sends translated signals to steering box and speed control  Programmed with C and Assembly  Written, debugged, tested using CodeWarrior and a Dragon12 development board

 Every time the IP camera receives a command, it stores the command in memory  If a connection is lost, the camera sends signals to the car to make it backtrack  If a connection is reestablished, backtracking stops

 processing  can communicate directly to RTSP server on camera  have an instance of a client