gion86:
Hi guys,
have you ever managed to fix this issue?I have a similar problem with a relay, car horn, and big 7-segment display all turning on during the time the horn is active!!
If you still read this thread I can give more clarification on the problem!
Thanks!
I did not resolve the shift register issue because it was just too unstable. I moved to a different solution of using an Arduino Mega, which gave me enough digital I/O's to construct a 25x25 matrix relay controller. It's been running fine over a year now.