Kev's Cool Hardware Hack for converting a Lego Mindstorms NXT Light Sensor into a Laser Module!

Other cool projects - High Power Rocketry: Level 1 Project, Level 2 Project, Level 3 Project, Launch Controller

Computer Controlled Christmas Lights

NEW!!! - Our new Robotic Hexapod Project (6 legged, insect like robot)

Total Project Cost - $16.99 plus shipping.
Time Required - Approximately 2 hours of tinkering.
Having an Alpha Rex with a Laser - Priceless!!!


Step 1 (Click for more pictures and details)
Get an extra light sensor and a laser pointer with an easily removable laser diode module.
Step 2 (Click for more pictures and details)
Remove the laser diode module from the laser pointer.
Step 3 (Click for more pictures and details)
Carefully open the light sensor.
Step 4 (Click for more pictures and details)
Remove the LED and Phototransistor from the circuit board.
The RED one on top is an LED (Light Emitting Diode) and is the one you will use to draw power from for the laser diode module.
Snip the leads off of this one as close to the plastic casing of the LED as possible.
The CLEAR one on the bottom is a Phototransistor (Light Sensor) and can be totally removed.
Step 5 (Click for more pictures and details)
Solder the laser diode module onto the leads that are left over from the LED paying close attention to the polarity.
+ is Red / Positive / Anode
- is Black / Negative / Cathode
Step 6
Test the laser.  Before aligning the laser and epoxying / taping / superglueing the module in place you need to make sure it works!
(Turn the NXT On, Select "View", Select "Light Sensor", Select "Port 3 (If using defaults), The Laser should now be on)
Step 7 (Click for more pictures and details)
The hardest part :) - Make it all fit inside the case, and align the laser beam out of one of the holes :)
I had to actually file and snip at the edges of the laser diode's circuit board to make it fit.
(Be VERY careful if you do this as surface mount components and circuit board traces are extremely fragile.)
Step 8 (Click for more pictures and details)
Test it Again, Assemble it all together, and Enjoy your robot projects with a LASER BEAM!!!
(I used a combo of Caulk, Superglue, and Duct Tape - I would have added a drywall screw too, in memory of my dad, if it would have fit)