Thread by @GregDavill

This is either a great idea, or a terrible idea.

I'm still not sure which...

*Easy* mode won't work. This chip doesn't have enough I/O for the matrix.

I need 27 IO pins. :/

😅😅😅

Plantation Resistors

So far so good!

First connection! 48 to go...

The rough plan I'm following

Slow progress, but no major mistakes so far.

Just tried to tin the end of the enamel wire I'm using, Very confused when it melted....

I had picked up a hair with my tweezers. 🤦‍♂️

Done. Time for a dip in the ultrasonic cleaner.
I don't know how else to clean this.

I do know that the ultra-clear resin used on the front of the display becomes cloudy with extended exposure to IPA. I'm just doing an IPA spay then dunk in warm water.

So I know I personally hand soldered this.
But looking at it without magnification I can't picture how something this fine could be done by hand!

The 30um wire is very easy to kink, so it still looks messy when examined under high magnification.

But it turned out great! Some of the BGA pads stayed as balls and others stuck to the iron.

I was using lead free solder, but I doubt that makes much difference.

I guess *tomorrow* I'll need to try programming it. 😁

Hopefully that goes well. I will cry if I got the part orientation wrong. 😂

It appears that I have connected the oscillator backwards... 😅

Consistent with test results, my current limited supply caps out at ~0.7V.

Additional issue: I'm using the CM49 package, and I just read footnote 4.

I have left vpp_fast disconnected. 😐

😮😮😮😮😮😮😮

I'm using Glasgow to program the ice40, as it has easy 0.1" header cables I'm using with ez-hooks.

A bit of troubleshooting as to why it wasn't programming. Volatges looked good, SPI BGA pins all look good.

I had RESET connected to A5. I'd told the glasgow software A4 🤦‍♂️

🤩

I'm missing 3 lines.

A7/A10/A12 on my wiring diagram.
Some quick rework should fix them up.

Fixed up the missing lines.

The wires that were soldered down first without much compliance had broken at the solder joint. This may have happened when I threw this in my ultrasonic cleaner.

Huge success! 😁