I was a little apprehensive about hand soldering the QFN24 chip for the keyboard, looking at it, the thing was crazy small! I forget how small things are after spending many hours with stuff zoomed a few hundred percent on the computer screen

(dont look too hard, my keyboard needs cleaning)

so i took the plunge

tinned the pads with a small amount of solder, applied a later of flux, clamped the chip with some tweezers and a clothes peg (nothing like having the right tools) and gave it some love with the iron 

finding the limits of my phone camera, and it looks better in person.

much soldering later and we have filled the pads

I burnt some code onto the attiny85, grabbed the nearest sd card with ili9341 running, added a battery and pressed the button

looking good!!

There are of course issues, my idea of using a clip on programmer is fine for the attiny85, but when the pi covers the chip, you can no longer program it!! need to add a ICSP header. Im also struggling slightly to get my attiny to behave as i want. Getting it to respond over i2c kills my sleep code, think i have some conflicting interrupts...

to be continued......