In message <3488E723.67FD@bc.sympatico.ca>, patrick roberts writes >I just started learning PIC controllers. I have a number of ideas >brewing. > >The first is a digital air pressure regulator. Sounds really easy to me. >I want to be able to turn a dial and have the limit displayed on a 7 >segment led. I also want the limit displayed without actually having the >pressure in the system, so a sensor reading line pressure is not >appropriate. > >A quick A/D and either a stepper motor connected to a manual regulator >or I was thinking of a rotory encoder to give a position of the air >reg. screw and then interpolating this into a digital readout, Or >perhaps I could read actual spring pressure on the diaphram? Or >something else > >The something else is what I would like some input on. Not much to do with the above, but I'd like some comments. I'm experimenting with air muscles, and need a reservoir and regulator system to hold the air pressure from a little 12 V tyre compressor to about 3 bar. I'll probably use something really crude like a mechanical tyre pressure gauge shutting down the compressor when the pressure limit is exceeded. That just gave me an idea! I'll use a scooter wheel inner tube as the reservoir! Leon -- Leon Heller: leon@lfheller.demon.co.uk http://www.lfheller.demon.co.uk Amateur Radio Callsign G1HSM Tel: +44 (0) 118 947 1424 See http://www.lfheller.demon.co.uk/rcm.htm for details of a low-cost reconfigurable computing module using the XC6216 FPGA