nuttaphong191 Posted April 13, 2007 Report Share Posted April 13, 2007 I have a very simple circuit that oscillates an LED with a program on the 16F628.I am using a 4Mhz crystal and I find that the program will not run at all when the capacitors connecting each pin of the oscillator to ground are connected, but runs when they are connected.I am using 22pf capacitors, I have tried 10pf and 45pf. The oscillator is a crystal oscillator and it recommends 18-35pf in the datasheet. Any ideas?I need to stabilise the oscillator as it will be used for data output. It's a PIC16f628 ::) Quote Link to comment Share on other sites More sharing options...
AN920 Posted April 13, 2007 Report Share Posted April 13, 2007 I have a very simple circuit that oscillates an LED with a program on the 16F628.I am using a 4Mhz crystal and I find that the program will not run at all when the capacitors connecting each pin of the oscillator to ground are connected, but runs when they are connected.I am using 22pf capacitors, I have tried 10pf and 45pf. The oscillator is a crystal oscillator and it recommends 18-35pf in the datasheet. Any ideas?I need to stabilise the oscillator as it will be used for data output. It's a PIC16f628 ::)What you are saying does not make any sense. Quote Link to comment Share on other sites More sharing options...
esp1 Posted April 15, 2007 Report Share Posted April 15, 2007 hi,Look at page 93 of the 16F62X datasheet.Are you using a series or parallel cut crystal? also note the possible requirement for a series resistor in one leg of the crystal.Have you correctly configured the PIC using the _CONFIG, to suit your crystal? Quote Link to comment Share on other sites More sharing options...
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