Simply check for the button still being down before you do your thing at wakeup (probably after a short 'debounce delay'). If the button isn't still 'down' then just go right back to sleep. --- Bob Ammerman RAm Systems ----- Original Message ----- From: "trossin" To: Sent: Thursday, March 27, 2008 2:55 PM Subject: [PIC] very slight ESD events wake up my sleeping PICs > > I've built a few "executive" (I'm just a grunt geek) toys and two of them > have the same problem. That is when I get up from my chair, they turn on. > Both of these toys have push buttons to activate them. When the button is > pushed they do their thing then go to sleep. I enable wake up on port B > change and use the internal pull up resistor. On my latest toy I added a > 1K > pull up to try to stop this problem from happening (it reduces the problem > but does not eliminate it). One toy uses the 16LF628A and the other uses > a > 16LF873A. One runs on two AA cells while the other runs on 3 AA cells. > > On the toy with the 1K pull up (the 16LF873A), I put the PIC in a metal > case > but did not ground the case. The case is just "floating". On this device > I > once had an arc to the case and it required me to pop out the battery to > reboot it. I think that grounding the case should solve the problem but > I'm > not sure. > > The toy with the 16LF628A is just an exposed PC board but has a 5 inch > twisted pair wire for the switch. > > Has anyone else had problems like this? It only is a problem for me with > projects that use the wake from sleep on interrupt feature. Any ideas on > how to fix it. I guess I could use at 220 Ohm resistor but the lower I go > the more power that is wasted when the button is pushed. > -- > View this message in context: > http://www.nabble.com/very-slight-ESD-events-wake-up-my-sleeping-PICs-tp16331156p16331156.html > Sent from the PIC - [PIC] mailing list archive at Nabble.com. > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist