I had this same idea a while back after seeing the propellor clock.

In SA the taxi industry is big, and gimmicky stuff is all the rage.

I thought if you put a single strip of LED's down the side of the vehicle,
then sequence the leds' with text/whatever as the vehicles' moving, so you
get banner advertising. Of course, the good part is people see the text
when they're not really looking, ie side vision. If you look directly, it
simply looks like they're all lit, and flashing.
You can synchro this to the speed of the vehicle to keep the font
proportional.

Exactly the opposite of the led displays being described, 'cause you can
also stare at one point on those and see flickering lights only if the text
is being scrolled.

Regards
Roland

At 12:01 PM 23/05/04 +0100, you wrote:
>Nope. It's not as complicated at that. In the case of the wand - you
>sync it yourself by the speed that you move the wand in space. If you
>move it too fast - all you'll see if a garbled mess. If you move it too
>slow - you'll see, (yet again), a garbled mess! This one's down to
>experience - you'll get the hang of it.
>In the case of the spinning cylinder with the LED's sticking out of the
>side - it's controlled by the motor. If it spins too fast - you'll see a
>garbled mess, (don't think I need to say what happens when it goes too
>slow?!)
>
>Cheers,
>Stuart
>
>-----Original Message-----
>From: pic microcontroller discussion list
>[mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of Lindy Mayfield
>Sent: 23 May 2004 11:54
>To: PICLIST@MITVMA.MIT.EDU
>Subject: Re: [PIC:] Single Row of LED's Illusion - How they do that?
>
>
>Hi,
>
>Thanks for everyone's input on this and please one more thing before I
>let this drop just for my understanding.
>
>Just looking at the ad for the waving pen that spells out something and
>reading everyone's input on the subject comparing it to a dot matrix
>printer it makes sense to me that the timing of the lights has to be
>synchronized with the position of the wand in space.
>
>So would this mean that in the light pen wand thingy that there is some
>sort of tilt mechanism there that synchronizes the lights with the speed
>it is waving back and forth?
>
>-----Original Message-----
Regards
Roland

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