Found the problem today. With a long cable, there's some cross-talk and the jittery rising clock sig
Found the problem today. With a long cable, there's some cross-talk and the jittery rising clock signal causes it to register as two clock inputs, I'll try adding a resistor on the data output line on the S/R side tomorrow to slow down the slew rate and see if that fixes it.
Here in pic - yellow is rising clock edge and blue is toggling data line.
Here in pic - yellow is rising clock edge and blue is toggling data line.
