Thanks for the help with the variable settings. This definitely helps as I'm sure I'm shifting out the right bits now.

I'm still not getting any response from the TLC5940 though. Now instead of randomly blinking LEDs it's just staying off. I think this is fine because I'm shifting out the right bits, but I'm still confused with the ordering of the LATCH, BLANK, SER.

If you look at the Timing Chart in the spec sheet they show the ordering, but there is this weird thing where they have a separate pulse GSCLK in addition to the main SCLK pulse. I'm not sure why they have this and I don't know how I'm supposed to do both at the same time..