Here I demo my laser bean trip wire that is powered and processes with my computer and an atmega328 microcontroller. Please watch my last video "link in video" to see how I built the light sensor.
Component list:
Photocell
2 10 k ohm resistors
1 330 ohm resistors
10 jumper wires
1 light emitting diode
a cheap laser - 630 to 650 nm, 5mw max
1 8 ohm speaker
