Must I need crystals?

[littletransistor]

hey there,

I'm making some PIC projects, with these chips 18F1320 and 16F628 where they have those built-in oscillators already. Should I need to put them again or just leave it without the crystal?

And I only have 32.768KHz crystal - I heard some PIC needs that.

 

[kchriste]

You don't need a crystal unless your project requires an accurate system clock speed.
Projects that need a crystal:
Clock
Frequency counter
etc

Projects that normally don't:
Led flashers
Alarm system
dice game
etc

 

[BeeBop]

hey there,

I'm making some PIC projects, with these chips 18F1320 and 16F628 where they have those built-in oscillators already. Should I need to put them again or just leave it without the crystal?

And I only have 32.768KHz crystal - I heard some PIC needs that.

You probably don't need a crystal, but it depends on what you are doing with these chip. The present day internal oscillators are fairly accurate and can do serial comms....

What do you have planned?

 

[littletransistor]

Oh, just making simple projects like LED flashers, music, some games. So I don't have to use these at all?

Also, maybe I'll be using the LCD panel - clock and some monitoring stuff.

I might be venturing into stepper motors too.

 

[futz]

Oh, just making simple projects like LED flashers, music, some games. So I don't have to use these at all?

Also, maybe I'll be using the LCD panel - clock and some monitoring stuff.

I might be venturing into stepper motors too.

None of that stuff except the clock needs the extra accuracy of a crystal. So as long as your PIC has an internal oscillator that gives you enough speed to suit, go ahead and use it.

There are some PICs that don't have internal oscillators. Those ones will need a crystal or other type external oscillator.

 

[Willbe]

There are also "ceramic resonators" (?), good to a percent or two.

 

[theo92]

i don't recommend resonator for timing intensive application...ie USB or serial....i also heard that they don't last long when compared to real crystal....i love crystal+driving caps*2.......but if there's too space limitation...resonators are still good enough