[itchief]

Hi Tom,

Could you suggest a way to increase KFlop to Konnect cable length over the recommended max of several inches?
Maybe a buffering IC in the middle or something? I would like to find a way to get stable connection on lengthes around at least 10 inches.
And maybe another one for lengthes of 20+ inches.

Regards,
Andy.

[TomKerekes]

Hi Andy,

Ribbon cable has a lot of parasitic capacitance between wires. We found an issue where signals on "long cables" can couple to KFLOP's Reset signal and cause intermittent KFLOP Resets. Adding a capacitor (0.001uF Ceramic) near KFLOP between Reset and GND will solve the problem. Having one Konnect board near KFLOP will also solve the problem. The capacitor can be added to any KFLOP connector. Here is a video (somewhat poorly recorded) showing 4 Konnects (196 I/O) on a long cable. Note we added a connector with a orange capacitor into KFLOP JP4.

http://dynomotion.com/Videos/Konnect4.mp4

Regards

[itchief]

Hi Tom,

So the only problem of a long cable is that parasitic capacitance?
And it may influence only the reset signal? IO's between KFlop & Konnect remain stable with longer cable length?

I've already added a 0.001uF to KFlop's reset, which solved intermittent resets caused by VFD's. So I'll now try Konnect with a long cable and see if it works.

Another question - does Konnect actually require all three VCC pins (3.3V, 5V and 12V) at JP6 to be connected? Or maybe just 3.3 or 5 volts would be enough?

Regards,
Andy

[TomKerekes]

Hi Andy,

Spurious resets is the only issue we are aware of. The KFLOP-Konnect communication seems very solid. There will always be some noise level/cable lengths that will cause problems.

Konnect only requires 3.3V and 5V to operate. The 12V signal is only provided in case it is useful to someone.

Regards

[itchief]

Hi Tom, it's now clear, as always when you participate. )) Thanks a lot for all your help!!!

Andy.