Testing the cathode board

Quick update, more will follow.
I've been a bit busy with some other stuff lately, I had to make 35 buzzer games (like this one) for a group of kids, so I spent most of my free time last week putting a bunch of leds, resistors, battery holders and piezo buzzers together. The rest of my time went to miscellaneous stuff like housekeeping and filling in my tax forms. Last night I finally had some time to get back to the cube...

I need some way to test if my cathode boards work after I solder all parts on them, so I populated a breadboard with 8 LEDs and wired them to the cathode board and an Arduino. The Arduino runs pretty much the same code as the cube will eventually in terms of refresh rate and how the cathode board is controlled. It took some time before I had everything working somewhat correctly, always double check your connections and don't mix up the MOSI and MISO pins...

But in the end, it works! One LED didn't light up, I didn't solder the transistor for that one correctly, easy fix. I'm still tweaking the code a bit, there's a bug somewhere that stops the brightness from functioning properly. I don't have any photos or videos at the moment, I'll shoot them after I fix that bug.

One thing that I overlooked is how bright a 0603 LED can be. I have a small power indicator LED on the board and that thing is just blindingly bright. I've already replaced the 150 Ohm series resistor with a 1K Ohm, but it's still too bright. I'll try a 10K tonight; all it needs to do is provide a visual indication, not light up the living room...