This part proved a bit challenging, I was up until 2am last night trying to get my timing and what not right... not really any luck. Fast forward to tonight.

Isn't this usually how it goes, usually a conversation with yourself. 

"Man! I just don't know why this stupid thing isn't working write.. I'm pretty sure my code is right.." 

checks code for the 50th time, makes some changes, tries again, still not working right. 

"mmm well that kind of looks like a 1... " for some unknown reason you look at the bottom of the bubble display only to find out that at 2am while in your half insane state you put the chip on the bread board backwards ....

"Oh ya, that will do it... "

Getting stuff on the board!

I will admit I am not one for writing reports or anything highly detailed but I am going to try this time,. really, hard to make this reproducible on your own..

Our micro controller of choice is an Attiny 84A, awesome little hunk of plastic that internally runs at 8Mhz (after you clear the divide by 8 fuse, more on that later.) A bunch of HP bubble displays that require you to raster the numbers in order to make a decent display, trust me 1Mhz is not fast enough.

So how do we control this display when the Attiny 84A only has, 12 pins 10 if you want to use I2C and even less since we need reset functionality.

The display itself has 12 pins 4 Anodes, and 8 Cathodes. I wont go into great detail on this little guy as Sparkfun has done an awesome job preparing you for the use of this device (https://learn.sparkfun.com/tutorials/bubble-display-hookup-guide), We control this device with only 3 pins :) 

Enter the 74HC595:

Probably the electronic hobbyists best friend on a bread board. This thing can turn 3 pins into 8 and cascade into even more with other 595's, 8, 16, 24, 32 .. etc all with 3 pins. It can also act as an input device! Amazing! so we are going to use 74HC595's to control the display.

Again there are hundreds of tutorials on the 595's out there that I will not be going into detail, aside from some code. I am sure there are some C library's for its use as well, but I like doing things the hard way.. I will update the details when I finish the library for the 74HC595. It's rather simple.