These (or the principals they employ) are the basic ‘gates’ used to construct logical control elements in LBP. The term ‘gate’ is really interchangable with operator, but from a convention perspective, a gate is normally the physical manifestation of an operator. Gates in LBP consist of pistons, magnets and magnetic switches, and as a consequence, logic relies heavily on directional switching. FALSE can be considered to be the equivalent of CONTRACTED, or more precisely, the signal that needs to be applied to a pistion to make it contract to it’s shortest length. TRUE can be considered to be the equivalent of EXPANDED.

As an example, consider the push button switch you can place on the floor. If you connect it to a piston and leave it, the piston will shrink to it’s shortest length. When you stand on the button, the piston will expand to it’s longest length.

Lets get started… the simplest ‘gate’ of them all…

The NOT Gate

The 2 Input OR Gate

The 2 Input AND Gate

The 2 Input XOR Gate

Interfacing With Other Elements

As mentioned above, logic in LBP relies heavily on the use of directional elements. Pistons can be contracted or expanded. A directional switch will (when activated, unless it is inverted) send a TRUE, or more accurately, an EXPAND. When it’s not activated anymore, it will be FALSE (or CONTRACT).

Many other items in LBP require different signals (On/Off for example). When this is the case, if the switch that provides the output you require is used to control other logic elements, you can use a relay. This is simply an piston that can activate a switch of any type you require.

Conclusion

That concludes our introduction to the basic gates and their construction in LBP. For information about building them, please check the hints and tips sections for information about materials, sizes, piston settings etc.