Well, that's was really my fault because I'm just starting with pics and learning better electronics. If you pay attention to the board layout you'll see that the pinouts of the board doesn't match the 16f877. That's because I used a Freescale MC68HC05C8A Microcontroler with that board. I just wanted to migrate to PIC without rebuilding the board, but just cut and rewire the incorrect pins. Thanks Peter for advice. On Thu, Mar 18, 2010 at 11:54 AM, PETER ONION wrote: > --- On Thu, 18/3/10, Matias Vidoni wrote: > >> @Peter >> The 16F877 has 2 pairs of voltage inputs. I mean, there are >> two pins >> labeled VDD and 2 pins VSS. >> Should I connect both pairs? Now they are connected. But in >> first >> place they not. > > YES, both sets of Vdd and Vss pins MUST be connected to the supply and to= ground. =A0Both Vdd pins need decoupling capacitors connected close to the= pins and going to a to a good low impedance ground point. > > Not connecting and decoupling the second set of supply pins was most like= ly the thing that caused your resetting problems. > > PeterO > > > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- = Matias Vidoni eMail: matiasvidoni@mvcom.com.ar MSN Messenger: matiasvidoni@mvcom.com.ar Skype: matiasvidoni WWW: http://www.matiasvidoni.com.ar Google Talk: matiasvidoni@gmail.com -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist