How to Make a Daylight Detector in Minecraft: Auto Lights
Three glass, 3 nether quartz and 3 wooden slabs make a daylight detector. How to make one in Minecraft and wire lights that switch on at dusk.
A daylight detector takes 3 glass, 3 nether quartz and 3 wooden slabs. Put the glass across the top row of a crafting table, the quartz across the middle row and the slabs across the bottom. Any wooden slab works, and you get one detector.
Where the materials come from
The quartz is the only part that needs a trip. Nether quartz ore is everywhere in the Nether’s netherrack, usually visible from the first few minutes after you step through a portal; mine it with any pickaxe. Glass is sand smelted in a furnace (see how to make glass), and slabs are 3 planks in a row, which gives 6 slabs.
How the signal works
The detector reads sky light and outputs a redstone signal from 0 to 15. Around midday in clear weather it reaches its peak; at sunrise and sunset it ramps up and down; at night it outputs nothing. Rain and storms lower the reading, and so does anything blocking its view of the sky.
Use it once (right-click, or tap on mobile) and it flips to inverted mode: the top turns blue and the output is strongest at night. For almost every practical build, inverted mode is the one you want.
Builds that use it
Automatic lights. Put an inverted detector on the roof, run redstone dust from it to a row of redstone lamps, and your street or courtyard lights up at dusk and switches off in the morning. Lay the dust one block under the floor, beside each lamp, and the wiring stays out of sight.
Doors that lock at dusk. Wire a detector in normal mode to iron doors or a piston gate. Powered iron doors stay open, so the gate is open while the sun is up and closes itself as the signal fades in the evening. Put a lever in parallel if you want to open it at night.
Night-time switches. Flip that logic with inverted mode and you can run something only after dark, such as a light-up sign or a mob farm that you want active only at night.
If you only need to know the time and not react to it, a clock is simpler. For the basics of dust, power and signal strength, read redstone basics before wiring anything long.
Small gotchas
- The detector is a slab-height block, so you can walk over it on a roof without tripping.
- Signal strength fades by one per block of redstone dust, so a weak dawn signal may not reach a far lamp. A repeater fixes that.
- Repeaters also add a short delay, which is useful if you want lights to come on in sequence down a street.
Common questions
How do you make a daylight detector work at night?
Use it (right-click on PC) to switch it into inverted mode. The top turns blue and it outputs a signal when it is dark instead of when it is light.
Does a daylight detector work underground?
Only if it can see the sky. It measures sky light, so a solid block above it cuts the signal.
Why is my daylight detector weak in the rain?
Rain and thunderstorms reduce sky light, so the output drops. Plan circuits around a threshold rather than a full-strength signal.
Sources & verification
Facts on this page are checked against these references and in-game behavior for the stated edition(s). how we verify.
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