Since the last log I’ve mostly finished the AVR code for loading data into the EEPROM. Then things slowed down a lot. Firstly, I wanted to build some of the circuit on strip board however the piece of strip board I have is a bit too small and it’s a very tedious design to prototype this way. Likewise with breadboarding - there would just be a sea of wires! Yes I could do it, but the data sheets are clear enough I decided I’d just send off boards for production - Chinese PCB services are cheap enough to take a chance on (and I have done this a few times now for my other project, an LED matrix controller so I’m not sure why I wa so keen to prototype this the hard way)

But then another thing came up: I wanted to make a change to the design to make the AVR more capable - there aren’t quite enough pins available for it to control some of the lines. In the end I decided this can wait until a second revision. The design change in question is to add a tristate shift register or three to act as a port expander. This would also potentially allow for using a smaller AVR to make up for the board space taken up by the shift registers. 

Then came the next challenge - Chinese New Year would slow down board production - I wanted to get an order in before then but in the end doubted myself enough that I didn’t - I was still thinking about that design change!

After that life (by which I mostly mean my day job) somewhat got in the way and nothing happened. Anyway a couple of weeks ago I tidied up the board design and today I finally submitted the order!