Hi. I'll try the hyperterminal but I can tell you... I have a button to connect or disconnect from serial port.
I have a Pset... to make the graphic of the voltage from the Pot.
In the moment I connect serial port and the my device (uC, Pot, serial, etc..) is off, nothing happens in the graphic.
In the moment I start my device, the graphic starts showing the voltage from the pot ( let's say 3 volts.) then, as soon as my hand moves from switch to pot, I change the position (to 1.5 v. maybe) and that change occurs 30 seconds later.
I mean, the uC is sending information all the time. If I turn off my device, the graphics keeps drawing until (I think) the buffer is empty.