This is a multi-part message in MIME format. --------------02AD3DE5E4DDFA428D7AB9AD Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit You have the right idea. If you only want one button but can tolerate a few more discretes, use the following circuit. Pushing the button will power up the pic just like you said, and at bootup set portb.1 high. Pressing the button again momentarily, sensed by portb.2, (polled or interrupt) and with a small timing routine will shut the circuit off. Depending on your routine, if you hold the button down too long, it may restart the power. Rick Les Otter wrote: > Hello > I am trying to move from a toggle power switch to a NO momentary membrane > switch. > > My circuit thoughts are :- > http://www.saurel.demon.co.uk/files/Membrane.bmp > > (Caps not shown) > where the membrane switch S1 supplies power to the circuit at startup, which > boots the pic. > The first thing the PIC does is sets Pin B0 high, so S1 can be released. > When the PIC detects button press of another membrane switch ("OFF" - not > shown) pin B0 can be set low, thus powering off the circuit. > > Is this a sound design concept, and anyone suggest how to do it better? > Can't find anything on Google / PIClist Archive or FAQ. > Thanks in advance for any help. > > Les > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! 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