A Laser for Vex!

Well, it isn’t going to bring down a satellite, but I’m happy to report that the Sparkfun Laser Module (below) works great with Vex.

All you have to do is replace the connector with a Vex friendly connector, or splice it to a servo extension cable. Just match the colors: red to red, black to black, white to white, and ignore the green wire (either clip it off, tape it up, or connect it with the black wires).

To control it from software, just configure a digital output and write a ‘0’ to turn the laser on, or a ‘1’ to turn it off. You can turn it on/off very quickly, so you can modulate the beam. The Vex Light Sensor does respond to the red beam very well, so you could use the laser/light sensor to make a laser-tag game.

They also sell a black plastic mounting bracket (above). If you slightly enlarge the two mounting holes, it will fit along the slot of a Vex slotted 1x1 Angle:

There were no warnings included with it, so I’m assuming it is safe to use around children and small animals, though I’m still not going to stare directly into it…

Happy hunting!

  • Dean

TOTALLY cool! :smiley:

cool. now I wonder if anyone knows how to increase the sensing radius of the light sensor… like perhaps a large lens or something

I’m not much with optics, but it seems like putting it in a small box with a frosted red filter might help. A red filter that was closely matched to the wavelength of the laser would help the sensor see only the laser light. And the frosting on the filter would act like a projection screen for the light sensor to watch.

Without any filter, the light sensor gave a reading of 60 (at the lowest) in my brightly-lit office, but dropped down to 10 or 15 when directly hit with the laser. With the room lights off, the sensor went to about 200, but still went down to 15 when hit by the laser. This is easily enough spread for direct-hit detection.


  • Dean

hmm from the values (60-15) looks like we’d definitely need some kind of optical filter to filter out ambient light, and a diffuser for larger surface area.

cool thing to KIV, though the first thing I hope to do this summer is something with legs on the vex :smiley:

this is awesome, there are a lot of great products at sparkfun…and the keep adding…i found something like this to for LED’s I tihnk it’s called dragonfly or something

Find some way to mount that on vex, with say with a release feature that hides it inside a plastic case until using some advanced gears it shoots out- along with 5 or so 50x magnifying lenses, and turns on. Oh, and make it have ultrasonics on the front so that it will do it automatically when it gets close to say, I don’t know, my sisters bed.

I wonder if the pointer you have would allow me to cheat at my local laser tag. However, I think they actually sense IR and the pointer built into the gun is for aiming/looks purposes only.

Yeah, that would be soooooo cool if someone could figure out a way to make one of the laser pointers from www.thinkgeek.com work with vex and be able to turn on and off.

I got a 50mW (the one on thinkgeek.com was 10mW) green laser pointer on ebay for 16 dollars and it is insane! During the day it goes about a mile but at night you can point to stars and stuff because you can see the beam, really cool. It should be easy to use it with Vex (don’t want to try because I don’t want to take it apart and ruin it), i have had it for about a month and the insides are starting to slide out of the case so you could pull it out and connect it to a digital output. Search ebay for one, they are well worth the money.

The red laser pointer module looks cool, I’ll have to order one.


why not use motors to turn on the laser mechanically?
i love those lasers that you can see in the sky

i went to Mont Tremblant last summer as like my first vacation and at 12pm they had a star party (best thing ive ever seen) and they used a laser to track the MIR twas cool

i bet you could do something similar with Vex, use a program like StarryNight to plot out where the star is going to go then move the vex robot based on that

cool, I will try that maybe it will work

Me and bloodsheddragon are thinking of building a laser tag system with the sparkfun lasers and with IR transmitters and recievers. I think it is going to be cool if we get this project done.