Client networking application Design Details
Erson is an Apache web-server running under Linux. Hence the client application had to be written for the Unix environment
We had a variety of communications methods to pick from: serial, firewire, ethernet, token-ring, etc. Ethernet became the chosen medium due to its prevalence and the fact that we were able to install an ethernet card on the development board. A variety of protocols could have been used, but we selected TCP/IP as the means of communications since it is supported in linux and we were familiar with writing networking applications using TCP/IP.
Thus the client program utilizes Berkeley socket programming to transmit the CGI argument passed to it to isky. The program uses TCP as opposed to UDP to insure that the data is transmitted. Due to the robustness of TCP, the command (a single character encoding the camera and desired direction of motion) is simply sent to the server. The application does not due any of its own error checking and hence a packet format is not necessary.