as the light sensors that came with my first and second rcx where not useable when you want a laser guided robot, i diceded to make my own light sensors
and here it is my first instructable :)
excuse me for my bad english i'm not good at spelling and i'm dutch so... please if there is something incorrectly spelled let me know then i can fix it or pay more attention to it
Step 1: get the stuff
ok first of all i used a way to light LDR (light dependent risitor) it did not have enough resitance so my light sensor is a bit sensitive..
but what you will need is a LDR that has about 3500 ohm's when you expose it to a simple laser pen
mine didn't have that much resitance so i fitted a aditional risistor of 1500 ohms.
but that is all up to you
ok what you need:
A conductive lego strip
A lego brik
maybe an aditional risistor