This video shows a loopback test on my RooStick - Roomba to USB Bridge that I got from Sparkfun. A loopback test is a good basic test to do for a serial connection to see if you can perform basic transmit/receive functionality. I use the RooStick to control my Roomba robot vacuum.
PuTTY is an SSH and telnet client. You can use it to send serial commands to a device connected to your computer through a COM port. To make the USB port act like a COM port, install the drivers that are on the Sparkful site. You can also get The Roomba Serial Command Interface there that will tell you what all the pins do.
RooStick - http://www.sparkfun.com/commerce/prod..., PuTTy - http://www.putty.org/
On this page of the site you can watch the video online Serial Loopback Test with a duration of hours minute second in good quality, which was uploaded by the user RuthJ180 25 April 2010, share the link with friends and acquaintances, this video has already been watched 19,022 times on youtube and it was liked by 22 viewers. Enjoy your viewing!