Methodology

The project made use of two crisscrossing lasers at the floor of the model. Each laser was positioned such that it hits an LDR which is also positioned at floor level. Even if one of the lasers was blocked (LDR receives no light), the system assumes that the CR is occupied, and thus the red LED will turn on.

Materials used for the circuit:

• 2 LDRs
• 2 Potentionmeters
• 2 laser pointers
• 2 red LEDs
• 4.7 k ohm resistors (2 pcs)
• 470 ohm resistors (2 pcs)
• 3.9 k ohm resistors (2 pcs)

The project was connected directly to the power source (5 V for the actual circuit, and 4 V for each of the lasers).