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using single resonator with multiple ic's

hi all,

Does anyone know if it is possible to use 2 or more picaxe chips, linked to only one resonator, so they keep time together. I was thinking somthing along the lines of this:

28x1resonatoridea.jpg

 

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the original idea is to run vast quantities of leds as a form of graphical display, i was thinking of using multiple ics all running the same program, serial to parallel shift registers, and external eeprom so each ic would only be controlling a smaller area, thus i could control the brightness of the leds via pulses, the problem being that when the system is showing dimmer light, there may be some out of synch pulsating, which running the ic's at exactly the same clock speed (hopefully) should eliminate.

thats the theory, anyway...

I am sure you have looked into the components section already, but this was not the answer: http://letsmakerobots.com/node/131

? :)

yeah, i looked into i2c, also daisy chaining shift registers, but wasn't sure about how well i would be capable of coding this with a single chip within the available program space  (i'm not the greatest programmer) also, i was also interested if it was possible on an academic level.

I like the idea, I like the question... but...

Doesn't a resonator cost, like, a buck or so? --Just use 2  

K.I.S.S. My friend.

This must be possible, but I think you might have to do it in a sort of master/slave setup where one PIC has the resonator, and the other PIC is set to "External clock" and connects to the first with a single wire.  You'll need a common ground, too, of course.  Now, the question is: which PIC pin should be used to supply the clock from the master?

Another way of doing it would be to use an external oscillator and make both PICs use "External clock".  But then, you'd need a couple of invertors to make up an oscillator, or something.

Hmm, doesn't the oscillator just generate pulses of certain frequency? Why can't it drive two (or any other number of) ICs then? My guess would be, the frequency will be a little lower, but it's not a huge deal, is it?

From the other hand, why would one need two PICAXEs to be using the same exact oscillator? Running two programs totally in sync would be tough task anyway; from the other hand, they might use different oscillators and still they can communicate (and synchronize) with each other via regular I/O pins...

Could it be done?  Maybe, and it may be as simple as you've suggested, but I don't think so.  It may be more trouble than it's worth.  And I can't visualize why you'd need to.

What application are you considering?

If you post your question on the Rev-Ed PICAXE forum, you'd probably get a definate answer.

Duane S

Wilson, North Carolina  USA

I think that there is a function to get clock from outside, just as I think there is a function to send clock.

I think! :)

I am sure that there is something about it, at least for the timer functions or something!

Good answer, ?

- Hey; It IS a good answer, I advice you to look at the commands!

thats a very wize suggestion, i shall look that up when i get home