KHMan wrote: > I've tried a lot of one-LED blinking without decoupling caps, > they all work.
PICs *usually* work without decoupling caps, but that could change with a power supply or ground line a little long or skinny, noisy stuff nearby, a cold solder joint, any number of things. The annoying thing is that the symptoms can be so confusing. Put a small cap to ground on the supply right next to the PIC. Small meaning low inductance, the actual value hardly matters. There are all sorts of religious wars over what value to put there, but the main thing is to quench any short spikes. Anything from about .001 to .1 uF ought to work, as long as it is physically small. Dave McGuire suggested 0.1 which is perfect for a ceramic chip, but if you are using a disk, that is probably a little high high. To be effective, the lines to both the PIC and ground need to be SHORT. That might not be the problem, but whenever anything unexplained happens, it is always good to be suspicious of the supply. --McD ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev _______________________________________________ Sdcc-user mailing list Sdcc-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sdcc-user
