New to Arduino, had an idea for a project. It's a laser projector, basically just a laser pointer that will bounce off of two mirrors that rotate in different directions for x and y movement. it will position info from a computer(most likely, probably just mouse x,y position) and use that to determine how much to rotate the mirrors.
There's a lesson on the site, "DC Motor Control Using an H-Bridge", that I will be basing the design on to learn from, but I was wondering about the motor used. It's just rotating small mirrors, so it doesn't need to be able to drive anything heavy at all...but it will need to be precise. It has to be able to start and stop moving very fast, all of this within say 30 degrees of rotation. Anyone done a similar project or have any advice on motor to use? I'm thinking maybe the HS-422 http://www.servocity.com/html/hs-422_super_sport_.html
hi
you need a stepper motor ( accurate positioning) or a nice fast servo motor with an encoder (fast movement and positioning). Not cheap or simple, so brace yourself. R/C servos could be used but they are pretty crude in terms of movement.
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I tried something similar, both with DC and steppermotors. My conclusion was that these motors are not able to move the mirrors anywhere near fast enough to get a usable X - Y scanner. At best i got some lines looking vaugely like a triangular waveform.
You need a device callled a galvanometer to move the mirrors fast and precise enough. I found this web site describing in detail the process of building your own galvanometers (and a complete laser scanner)
http://images.google.dk/imgres?imgurl=http://hackedgadgets.com/wp-content/galvos.jpeg&imgrefurl=http://hackedgadgets.com/2006/07/10/home-built-laser-projector/&h=528&w=699&sz=60&hl=en&start=7&um=1&tbnid=Tz_nbUFqMKrYkM:&tbnh=105&tbnw=139&prev=/images%3Fq%3DLaser%2Bgalvos%26svnum%3D10%26um%3D1%26hl%3Den%26safe%3Doff%26client%3Dfirefox-a%26rls%3Dorg.mozilla:da:official%26sa%3DN
But be warned it's a very complex thing to build your self.
I realize the galvos would be the way to go for speed, but also I'm not trying to make anything that would be doing pre-scripted movements. I wanted to have it linked to my tablet PC and take it's XY position info from the mouse position. So basically I would be able to draw or write on the tablet and have the laser follow the same path. Since it would only need to keep up with hand movement, I figured that a motor could be capable of keeping up as it is nowhere near as fast as those scripted drawings. Even if it doesn't work well, I still want to try just to get more familiar with the Arduino.
@Daniel2
I'll look into those types of motors. I was thinking of an additional sensor on it to determine rotation, not too familiar with motors so I didn't realize there were ones that would give me positioning info. I'll look into those, thanks!
If you just want the laser to follow the X / y coordinates of the tablet screen, and see the red laser dot moving around it might work.
But you will not get a persistent image of what you are drawing on the tablet.