[SOLVED]Choosing oscillator for PIC

Thread Starter

Pushkar1

Joined Apr 5, 2021
222
I have one basic question, every microcontroller need a clock source. There are two options internal or external oscillator for Microcontroller.I am looking for specific reason i don't understand yet when should choose internal or external. I appreciate all help
 

BobTPH

Joined Jun 5, 2013
3,682
Basically the internal oscillator is about 1% accurate. If you need more accuracy, use a crystal.

An example, for a group dance performance, I made belts with RGB LED strips that each of us wore, and they were individually choreographed to the music. Over the 2 1/2 minute number, an internal clock would have put the out of synchronization by as much as 2 seconds or about about 3 measures in the slow Waltz we were doing. An external crystal solved this problem, and they stayed synchronized even better than we, the dancers, did!

Bob
 

Dodgydave

Joined Jun 22, 2012
10,050
It depends on how fast you need to perform instructions, if you're just flashing lights or nothing of major programmes, then internal is fine, but if you're using a high speed data scan and refreshing a display , usb lines etc, the the fastest clock speed is better so Xtal is best.
 

BobaMosfet

Joined Jul 1, 2009
1,850
I have one basic question, every microcontroller need a clock source. There are two options internal or external oscillator for Microcontroller.I am looking for specific reason i don't understand yet when should choose internal or external. I appreciate all help
@Pushkar1

You want a straight answer without hyperbole. Here is the simple TRUTH:

Simple- External clocks are usually MANY times faster than internal. For example, an internal might only reach 8Mhz max, but an External oscillator could be 16MHz or 20Mhz. In processing, the more clock-cycles, the more you can do.

*ALWAYS* go faster. Period.
 
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