[Joey] likes to dabble in laser projection, building his own hardware and writing the software that drives it. One way that he tests his setup is by replacing the laser assembly with an analog oscilloscope. This allows him to ensure that the driver board is receiving data from the software, and translating it into the correct electrical signals to drive the motors controlling the mirrored redirection of the laser beam.
In the video linked above [Joey] walks us through this process. It starts by connecting scope probes to the digital-analog-converter card that outputs image data for the projector. From there the XY mode is used to map the two channels perpendicular to each other; the motors that these signals are meant to control have mirrors that also move perpendicular to one another. After adjusting the scale and the timebase you will see the pattern the laser dot is meant to trace.
[Joey] entered this in a Tectronix contest. There’s plenty of other interesting entries to browse though. If have an entry that you’d like to see featured, or if you come across any other interesting stuff, don’t forget to tip us off.
With the availability of webcams and projectors, multitouch and interactive demos have become increasingly popular because they’re so easy. Students at the University of Tokyo took a new approach that uses lasers instead. They created Sticky Light, which uses mirrors, a laser, and a single photodetector. Unlike camera-tracking setups, this system requires no visual processing. The laser moves around and bumps into dark objects, sticking to them. It can follow drawings on the table or objects in space, such as shirt designs. They also created a few basic games and a demo that makes sounds based on the movement of the spots. Video of the project after the break.
Continue reading “Sticky light”
[kap4001] built what has to be the simplest laser scanner possible. It’s two servos strapped together with zip ties plus a 5V laser module. They’re connected to a Pololu serial servo controller. The laser is pulsed by switching the DTR line. You could use it to draw images like the one above… except that’s an 85 second exposure.
[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.
Continue reading “Laser POV projector”
I found [Stefan]’s work through his older, but interesting TinyProjector project. He opted to use multiple diodes in various configurations with rotating mirrors to create images. He’s built quite a few interesting projects over the years. The WeatherTank is pretty sweet.
I’ve seen a few simple DIY laser projectors that just oscillate the beam. This one (scroll past the pong game) has 16 lines of resolution. Sixteen mirrors are rotated by a motor, and an AVR controller pulses the laser to draw the image. Via Asish’s Programming Journal (Worth checking out, he’s been doing several webcam laser pointer projects.)