DIY: Interactive LED Stair Lighting

Place an LED light on each stair step so that the stairs light up when the tripwire is activated, allowing the stair user to see. LEDs simply need power to flow through them to light them up. They need to be connected to a resistor. Figure out the type of resistor you need by subtracting the LED voltage from the power-supply voltage and dividing it by the LED current. To connect one component to another, use a wire stripper to strip the insulation off of the wires to be connected. Wrap the wires around each other and heat solder with a solder iron. Put the solder iron on the conductors and wait for the solder to cool. Wrap the wires with electrical tape.

Wire the LEDs in parallel to minimize power consumption. With parallel circuits, all the LED lights have their own positive and negative paths to the circuit. Therefore, power flows directly from the power source to the LED and back to the power source, instead of hitting each LED light along the way.

Screw the wall-mount bracket on a nearby stud on the opposite side of the wall next to the stairs.

Connect the photoresistor to the power source and to the controls that operate the LED lights on the stairs. A photoresistor is a device that controls currents based on the intensity of the light shined upon it. Position the photoresistor so that the laser touches it, which causes it to interrupt the circuit and prevent power from flowing to the LED lights, causing them to turn off. When someone walks past the laser trip wire, the power will flow to the LED lights and cause them to light up. A photoresistor makes a circuit operate when light shines on it while stopping when light doesn’t shine on it.

Insert the laser pointer into the wall-mount bracket so that it shines a laser directly on the sensor. To keep people from bumping into the laser pointer, drill a hole through the wall for the laser to shine through.