(click to enlarge)
Using the great HiTechnic IRLink Sensor, you can operate the PF motors remotely. Since PF motors are relatively cheap and easy to come by, this gave me an idea. Can I design a system that uses PF motors to operate a pneumatic valve. The answer is yes.
The PF motor shaft is equipped with a 24 tooth cluch gear. That clutch gear turns a 40 tooth spur gear. In one of the outer holes of the spur gear is a piece that is connected to the valve lever throw. It is a rather simple construction that works great. This is the system by which I controlled the valve that operated the end effector of my Lego Flexpicker. It is very dependable. In fact, after I built and installed it, I often forgot about it functioning.
What is so great about this idea is that it can be controlled with a PF remote control as well as the HiTechnic IRLink sensor and up to eight valves can be controlled using only one port. With some creative building and blocking the signal at the right time, you can basically build a system where the sensor can control many more than eight valves.