How to make a bud switch minecraft

"Block update detector" redirects here. For the block, see Observer.

The Block Update Detector, or BUD switch, is a redstone mechanism that uses quirks in the game in order to detect changes in nearby blocks.

There are many different designs that are all based on the same general idea: a redstone circuit is put in a state where it should be following a mechanic, but the game has not updated the block to follow this rule. This unupdated block then functions as the "sensor".

You can create a BUD switch using this by linking up using both sides as the output of the BUD. Video describing this phenomenon: T-BUD Edit.

When an adjacent block changes state in some way, the game updates all adjacent blocks - including the sensor block - and powers them up. The circuit then performs some other action and, with most designs, goes back into standby.

Note: Most of the BUD switches listed below do not work on Bedrock Edition, since redstone is largely separate from block updates.

What it detects[]

The BUD switch detects the following events when they happen next to the sensor block:

• Placement of blocks
• Destruction of blocks
• Water or lava level changes
• Freezing of water or melting of ice and frosted ice
• A g