Interesting that it won't work, considering I've built several. I first saw the concept at the Ontario Science Centre. They have a column of lights on the way doing this. The instructions are to move your head back and forth while looking at the column. There is also a mirror mounted where you can see the lights in the mirror and the mirror can oscillate back and forth. On of the bus tunnel stops in Seattle also has a public installatoin of these light columns. There are about 20 columns of blinking lights randomly positioned around a large wall. Each one is showing a different picutre or word using this technique. The only way to seem them is moving your head. The first one I built was the "picture stick" in Popular Electronics several years ago. That one was designed to swing by but it does work when you move your head. I've also built the "subliminal clock" featured here: http://home.mweb.co.za/gr/grrr/picmicro/clock.html It is designed to be stationary and the viewer moves their head. I've done a couple of variations of my own as well. I'm teaching myself to interface the PIC to a PC through a serial port right now. One of my back burner projects I plan to do with a serial connection is a display that will get text data from the PC and show it on a column of LEDs this way. Jason ----- Original Message ----- From: "Jake Anderson" To: Sent: Sunday, May 23, 2004 3:20 AM Subject: Re: [PIC:] Single Row of LED's Illusion - How they do that? > also wont work > several reasons > your ear and eye are connected so that if you turn your head your eye > automatically compensates so you stay looking in the same direction (unless > you are specifically looking at somewhere else) > this works up to about 10Hz so you have to shake your head faster than that > to get anything > > shaking your head faster than that > a) isnt accurate enough to give a decent picture > b) hurts > c) looks really silly -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.