Tinkering around and thought Id ask, is there any sneaky downfall to running a 328 chip to standard standalone components on a standard ribbon cable (14 conductor, 28awg, 2 inches) versus a copper trace the same length, width and distance.
Common sense says there wouldnt be to me and my simple electronics knowledge, but again and again I still see people demonstrating weird problems by hidden things like resonance and attenuation in small traces or weird resistance issues and I figured Id just ask if anyone had any other ideas along those lines to watch out for.
Also is there a theoretical limit to how long a trace can be from chip to say resonator or crystal and still have the 328 function properly, I mean in real distance inch to feet or more?
Thanks in advance, Ive got the connect this to this basics, but definitely don't have the math side of things, like heat dissipation, resistance over distance and so on.
For the resonator/crystal, no more than 1" is my rule. For an LED, your ribbon cable can wrap around your house and you might see the LED dim a little. It really depends which parts you are talking about. Do you have anything specific in mind?
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The Quick Shield: breakout all 28 pins to quick-connect terminals
Just a tiny robot action based on a standalone and wanted a slightly different angle for chip access versus the motor board mount so I was going to bend the 328 to a diff position on the end of a ribbon cable around 2 or 3 inches long, so I can just drop in a new chip (preprogrammed) rather than try to program in situ.
Just wanted to see if I was missing something in the idea.
As mentioned the crystal would be a problem over 2-3" of ribbon cable. Everything else should be OK as long as you aren't feeding the clock signal somewhere else or have any high-freq inputs to a counter etc.
I meant chips preloaded with a different sketch, I didn't want to have to lug the laptop to the project every time I wanted to up date something and a I didn't want to lug the project base back from where it is every time ( large garbage can half a mile down a hill both ways, ok maybe only one way, but the circuit space is very small) so I was just going to drop a new chip in place when I had to make a sketch change.
In my original set up the standalone was in a bad angle to drop the chip and I didn't want to pull everything and redesign the mount, really limited space. So that was where the idea came from, just sort of dangle the chip on like a plug end.
So you will want to extend the crystal connections, it might not work if the wire is too long due to the inductance of the wire. How about using a ZIF socket (zero insertion force) socket:-
I couldn't fit a standard board in the space I have, so I its pretty scrunchy thats why I wanted to use the chip tuckable instead of lock mounted to the motor board, that and after the first design I realized I hadnt got it perfect and dint want to start from scratch, just lazy I guess ;D
But I now have it on a two inch ribbon with the crystals and caps and its working fine, thanks for the info.
