I got into pneumatics because I thought of it as a way to get around the 3 input 3 output limits of the RCX.
My first goal with pneumatics was to build a gate to allow me to use boolean logic and state machine design techniques to build advanced pneumatic robotic controls.
Embedded inside the structure is a pneumatic switch. There are two inputs into the OR gate. Each input controls the pistons in the OR gate. If either piston is expanded, the pneumatic switch is thrown one way. If both pistons are contracted, the switch is thrown the other way.
The gate can be configured as either an AND or an OR gate, depending on how the tubing is hooked to the pistons and valves. With this pnematic hookup configuration, a boolean NOT can be achieved by swapping the two connections to a given piston, or the outputs of a switch.
I used three of theese gates to produce an XOR gate to do binary pneumatic arithmetic in my pneumADDic adding machine invention.
MLCAD building description in a ZIP archive
OR gate configuration
AND gate configuration
