I have been working a little on this project in the recent months, designing a new PCB using different parts and so on, but I didn't really have time to assemble and test it properly. Recently I found the PCBs in a drawer, found the matching parts, and decided to give it a go. Behold, version 3.0:
and the back side:
I'm using a much smaller PCA9554 here, which has pretty much the same I²C interface. I also put all the parts on the back, so that you can stack this board with the display more tightly.
Just like version 2.0, it has friction-fit pin headers, so you don't even need to solder anything. As a bonus, I added a header for a SSD1331 display module, which you can simply plug in there. Only one problem, the module is too wide and covers some of the buttons.
I also used different buttons — initially I wanted to use the same kind that is on the Pro Mini boards for reset, but then realized that the "quiet" ALPS buttons fit that footprint too. Well, they almost fit — they are a bit too wide, and stick a little bit out on the D-pad side. Oh well.
Overall, I don't think the improvements are worth rolling a new version on Tindie — and I still have a bunch of version 2.0 ones to sell. However, I'm already thinking about version 4.0, which will be bigger, have footprints for multiple different display modules, and will use an ATtiny24 to do de-bouncing and buffering, just like on #Micro:Boy. It can take a while to finalize that one, though.