View Single Post
Old 02-14-2015, 11:54 PM   #1692 (permalink)
MPaulHolmes
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,368
Thanked 1,202 Times in 765 Posts
Heck yes I'm OK with off topic traffic! Don't make me post another naked picture of Kim Jong Il. hold me back...
EDIT: REMOVED PICTURE OF NAKED KIM JUNG IL... they are liable to take down ecomodder if it was discovered. It's not worth the risk! haha

I could definitely use beta testers. They should be fine, as it's basically the same thing I've tested. But I passed a kidney stone doing like 10000 different variations of component positions and routes so as to make it a good 2 layer layout, with good ground and power planes.

I would use shielded 7 wire cable like this for the interface:
Buy High Quality RS232 extended distance cable to eliminate signal noise and loss of data

The PWM signal should be from something like a pwm channel in a microcontroller, or an AND gate, so that it's actively forced high or low. I've tried it in a few noisy environments like big high frequency switching transformers, and haven't had any problems. Don't use a pull down resistor to cause the pwm to change from high to low (or pull up resistor to go from low to high). Different lengths of wire don't matter much. Propagation delay for current in a wire is on the order of 1 NANO second for each 6 inches of wire. But there is going to be a variation of 10's of nanoseconds from the optocouplers between different FOD8316's.
__________________
kits and boards

Last edited by MPaulHolmes; 02-15-2015 at 09:20 AM..
  Reply With Quote
The Following User Says Thank You to MPaulHolmes For This Useful Post:
e*clipse (02-15-2015)