Regarding your program, did you know there are very good sample codes using the 74HC595 ?: the shiftOut function.
See :
https://www.arduino.cc/en/Reference/ShiftOut
Sorry everybody that is helping that I disappeared, I got swamped after my last post.
Paul - unfortunately I haven't had a chance to look into it yet, and only have enough time tonight to post a quick reply to let you guys know I'm still here. I should be able to look into these other devices for a bit tomorrow. I actually have considered the MEga, but I think I still need more I/O than that.
Also, thanks for bringing the total current limitation up. I didn't see that on the datasheet and if I do use that expander, you'll have saved me.
You're right though, I am not sure yet exactly how many inputs and outputs yet. I have made some of the cabinet and just started the playfield; haven't got to start actually working on the electronics yet and it still might be a few weeks before I do. As far as IO, I just have a general idea. For output I will most likely have 5 door lock actuators, and several tiny 12v solenoids powering gates and a bunch of LEDs - maybe ~40. For input I'll prob have 20+ hhomemade rollover switches and 5 or so IR reciever pairs for IR tripwires.
Mike - These lightstrips - can you place the LEDs individually to use as indicators various places on the playfield? If not, that still sounds like a great way to do ambient color-changing light.
Btw - I tried moving the pins down one so I am no longer using pin 13 just in case, and I added the capacitor but the circuit is still not working for some reason.
Thanks everyone.
Just in case anyone is interested and this helps in any way, this is all I've got so far...
Yes you can get the Neopixels as either strips or individual LEDs. There are two sizes of individual LEDs 5mm and a jumbo 10 mm. They all take just one pin to drive as many as you want. Search for them on the AdaFruit site or other places under the name WS2812b.
You can get them as thru hole parts also:
https://www.sparkfun.com/search/results?term=ws2812
Only 40 leds? Won't there be some multi-digit 7-segment displays for scoring?
PaulRB:
Only 40 leds? Won't there be some multi-digit 7-segment displays for scoring?
Paul - I would love to have 7 segment displays but for budget reasons I am planning on just using a 16x2 char lcd up at the front of the playfield rather than a large (admittedly much more dramatic) display on a backboard.
The estimate of 40 LEDs are for indicator lights that show you where you need to go and then decorative LEDs to flash and light up the playfield. I am really stretching things, trying to get this all built for under $200.
Btw - I think those addressable through hole LEDs are awesome. I'm looking to see if they are available from China but can't seem to find them. Any ideas?