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Topic: replacing resonator with crystal? (Read 703 times) previous topic - next topic

unsped

Mar 03, 2008, 06:44 pm Last Edit: Mar 03, 2008, 06:45 pm by unsped Reason: 1
i notice the modern devices clones use a resonator also.

i have a boarduino and have a problem using a max72xx that does not happen on my arduino NG and seems to be related to the serial input i have feeding the boarduino. im basically sending the arduino bytes that it uses to light up appropriate rows, leds, etc.. when i have the boarduino generated patterns itself its fine. but when i have it parse the serial data i end up with 'noise' on the display. like its occasionally missing or inserting extra commands into. this goes away when i swap it for an arduino NG.

i noticed it uses a resonator instead of a crystal and am wondering if i bought a 16mhz crystal if there was anything preventing me from swapping the resonator for it? is there a reason they are using resonators? it seems like crystals cost about the same.

kg4wsv

The resonator has capacitors built in.  A crystal requires two external capacitors, making the circuit a bit more complex.  I seem  to recall that crystals are more accurate/more stable than resonators.

-j


unsped

#2
Mar 03, 2008, 09:10 pm Last Edit: Mar 03, 2008, 09:12 pm by unsped Reason: 1
they are more accurate, which is why im considering trying the crystal route and see if it clears it up. that makes sense why they use resonators though.

looks like (1) 16mhz crystal and (2) 22pf caps to ground is all i need.

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