[shakirfm] sent us this LED persistence of vision (POV) laser projector that can display dot matrix style text. The laser projector contains a rotating mirror assembly and 5 lasers. We’ve covered other POV projectors,but this one is a bit different. The mirror assembly rotates using two cooling fans. Controlling on/off times of the lasers along with the mirror speed, it is able to project 8×5 dot matrix ASCII text onto a surface.
[youtube=http://www.youtube.com/watch?v=oBnmHe6SG4c&hl=en&fs=1&rel=0&color1=0x3a3a3a&color2=0x999999]
The Atmel 89s52 contains a built in user interface which can control the horizontal character width, scroll speed and the number of characters displayed at a time. It can also store preset 10 character text messages internally, or accept text via the serial port from a PC. Eventually SMS messages from a GSM phone will be supported. [shakirfm] has more details and ideas for improvements here.
What a unique invention, I’d say that guy got a good grade :]
it’s a pretty interesting idea though, sure, LED POV’s used to be the big thing, but taking that idea to a laser array was brilliant, And it projects!
I really like the idea of using multiple lasers, makes things a bit easier.
When you do serial to hyperterminal, you should use a line feed, then a carriage return. (that way the text will line up to the left side)
0x0A = Line Feed
0x0D = Carriage Return
Other than that, it was an entertaining project.
i find that using a single mirror and a steeper motor that moves the mirror 40* back and forth seam suitable
“WOW thats a nice improvement keep the good job on development all the very best to u guys”.
For others on this site:
these guys have put their whole hearted effort and brain into this job please give them the lead and guidance. this group of young engineers have the potential.
@ Odin84gk: yeah i’ll do that. thanks :) glad you found the video interesting.
@ BiOzZ : well, i tried using a stepper motor at first, but it doesn’t rotate fast enough to maintain the minimum 30 fps required. and if you want a to and fro motion, somehting like the tinyprojector featured here earlier is the best bet i think.
@ scott : you’d be surprised at how thick my examiner turned out to be. the man wanted me to display a jpeg image using this thing! glad you liked it :)
@tuckie: well, aligning the 5 lasers so that it could display legible stuff was the hardest part actually. required a rather mechanically complicated assembly with provision for real fine adjustment of angle.
@ramesh: thnaks for the encouragement! :)
eeks.. where did those yellow smilies come from. hmm.. heres a thought.. they could be replaced by smiling skulls and bones :]
yes, looks great….
i think you can do greats mods, i remember one time i do anything like that, i do an spectrum analyzer for audio, he are like scope !are all analog!,…. actually i´m tryin to learn how to program… i do flash led and now i got new horizons, i will try near to got bi-mechanical scaned lasser, if you got me i will they project like fisheye signal from pick up readers… maybe someday.
EQU this awasone.
Well, I built one of these in 2001 using 32 green lasers. I still have it. It’s far larger of course and was the third one. The first was made with some cheap red laser pointers and the second was made with eight green lasers. The scanner system I made however uses an oscillating mirror and draws both forward and backward, retracing the text for intensity. I should post pictures if anyone is interested. I don’t think there was a Hackaday back then.
I realise this is a very old post but if you are still around I would be VERY interested in seeing your other machines. Cheers.