Minecraft Proximity Sensor

Most proximity sensors in Minecraft are incredibly complex; this one, however, is simple and takes up very little space.

• To build this proximity sensor, start by placing a command block.  Type “testfor @a [r=5]” into the block’s interface.
• Place a redstone comparator next to the command block, facing away from the command block.
• On the other end of the comparator, place another command block or another function to be activated when someone is in range.
• Place a short, repetitive circuit leading to the first command block.  Do this by placing redstone next to the command block, and a repeater leading into the redstone.  Place another repeater behind the first, and redstone to the left.  Place repeaters along the first two, except in the opposite direction.  Connect the second set of repeaters to the redstone next to the command block.
• In the end, the circuit should look like this:

• The redstone on each end of the circuit is connected.
• Right-click on each repeater once.
• Briefly activate the redstone by placing a redstone torch next to the redstone and then immediately breaking the torch.

It is extremely simple to set up.  To adjust the radius, simply increase or decrease the number in the r=5 equation.

Here is a really great video demonstrating the above sensor.  (Note: this video, and any other videos already on Rocket’s Game Corner, is not my own.  I will note if one is, in the future.)