In Minecraft, the observer watches the block in front of it and sends a redstone pulse when it detects a change. You can use an observer to build traps, farms, flying machines, bridges and so much more! Let’s explore how to use an observer.
Sides of an Observer
There are 3 important sides on an observer:
- FRONT – The face of the observer watches the block directly in front of it.
- TOP – The top of the observer has an arrow which shows the direction that redstone pulse will travel.
- BACK – The back of the observer sends a redstone pulse each time there is a block/state change.
(Note: In Bedrock Edition, the observer can currently only detect block changes and not state changes.)
Steps to use an Observer
1. Place the Observer
First, you need to place an observer. If you don’t have an observer in your inventory, you can quickly make one with a crafting recipe for an observer.
The game control to place the observer depends on the version of Minecraft:
- For Java Edition (PC/Mac), right click on the block.
- For Pocket Edition (PE), you tap on the block.
- For Xbox 360 and Xbox One, press the LT button on the Xbox controller.
- For PS3 and PS4, press the L2 button on the PS controller.
- For Wii U, press the ZL button on the gamepad.
- For Nintendo Switch, press the ZL button on the controller.
- For Windows 10 Edition, right click on the block.
- For Education Edition, right click on the block.
2. Front of Observer Watches the Block
The face of the observer watches the block directly in front of it for either block changes or state changes. A block change occurs when a block is either placed or removed. A state change occurs when the state of a block changes (for example: eating a piece of a cake changes the state of the cake block).
3. Back of Observer emits a Redstone Pulse
The back of the observer sends a redstone pulse each time there is a block/state change. The redstone signal is level 15 so it’s strong enough to travel 15 blocks.
4. Place Redstone Dust and a Redstone Lamp
Next, we’ll place redstone dust and a redstone lamp at the output so that you can see the observer activate and send the redstone pulse.
5. Example of a Block Change
When we place a cake in front the observer, it sends a redstone pulse. This is considered a block change by the observer.
6. Example of a State Change
Each time we eat a piece of the cake, the observer also sends a redstone pulse. This is considered a state change by the observer because the state of the cake block is changing as the cake gets smaller.