cd74ac164 test

Set up a test prior to releasing the 9x9x9 LED cube driver board.
Can’t really see it in the picture, but there’s a little AOI518 in the middle.
I let this run for half an hour, watching this code run.
Measured 2.07V to 2.1V Vf on the LEDs, with 20-21mA thru the LEDs with 100 ohm current limit resistor pack networks.
Transistor is on nearly the whole time, turned off just enough to prevent ghosting while data is shifted in.
Could see the slightest flicker on the LEDs when the SPI transfers occurred, adding the 1K pullup to +5 took care of that while the MOSFET is off.

#include <SPI.h>

unsigned long currentMicros;
unsigned long previousMicros;
unsigned long elapsedMicros;
unsigned long duration = 100000;
byte enA = 8;
byte enB = 9;
byte count1;
byte count2;

void setup(){
  // pinMode (ssPIN, OUTPUT);
  // digitalWrite (ssPIN, LOW);
  pinMode (enA, OUTPUT);
  pinMode (enB, OUTPUT);
  //SPI.setDataMode(2); // SCK default high

void loop(){
  currentMicros = micros();
  elapsedMicros = currentMicros - previousMicros;
  if (elapsedMicros >= duration){
    previousMicros = previousMicros + duration;
    count1 = count1 +1;
    if ((count1 & 0b00000010) == 0b00000010){
      count2 = count2 +1;
    digitalWrite (enA, LOW);
    digitalWrite (enB, LOW);
    SPI.transfer (count1);
    SPI.transfer (count2);
    digitalWrite (enA, HIGH);
    digitalWrite (enB, HIGH);

There’s two enables as originally I had a MOSFET for each shift register, then changed to 1 to stress it more, figuring I’m going to 81 LEDs when the cube is done.

Silly question, but is there a question in your posting?

Sounds like its working ok.

Nope, no question.
Here’s the updated layout. All squeezed into a 10cm x 10cm board.
9x9x9 cube is under construction now.

A 729 pixel cube, is it?