I am trying to send PWM, clock, latch and blank signals from Arduino through a series (16) of TLC5940 Breakout boards and on to a grid of 512 individual controlled LEDs six feet away (RJ45). I am using op-amps to help get the serial signals pushed through the large number of boards. Power and Ground are in parallel.
Of course, I am having problems. The set-up, as pictured, works well until the 9th or 10th board, then things get wonky. They are getting power but not individual control -just flickering.
I am trying to troubleshoot. The whole thing is powered by 12 V, 30 A switching power, buck converters for three different voltages (10 V for Arduino, 4.7 V for op-amps, 6V for boards and LEDs).
I am wondering if I should tie all grounds to a single common line back to the power source (V-) or do the individual voltages (10 V, 4.7 V, 6 V) need their own ground line back to power source? Example: the five op-amps - 4.7V+ and 12 V- single line common ground? - or should they have their own ground line all wired back to the 4.7 V converter and its 4.7 V-?