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Now combine your skills into one device: an automatic night light that switches an LED on when it is dark and someone moves.

You will read two inputs, the LDR for light and the PIR for motion, then drive one output: an LED.

Assign each part a pin: the LDR on an analog input, the PIR on a digital input, and the LED on a digital output.

In setup, mark the LED pin as an OUTPUT so the board can drive current to it on command.

Each loop, grab a fresh light value and the current motion state so your decision uses up-to-date data.

The light should turn on only when it is dark and motion is present. Use && to require both at once.

When both conditions hold, drive the LED pin HIGH to light it up for whoever just walked in.

Otherwise, set the pin LOW so the light goes dark again when motion stops or the room is bright.

People dislike a light that snaps off instantly. Add a short hold time so it stays on a while after the last motion.

The light check matters: requiring dark means daytime motion is ignored, saving power and avoiding pointless blinks.

Swap the LED for a relay and you can switch a real lamp. Same logic, bigger impact in your hallway.

What condition turns the night light on?

You merged an LDR, a PIR, and an LED, using a threshold and && so the light glows only in the dark with motion.