Is a 9x9 keyboard technically doable on Pro Micro?

Narann · 02 Apr 2018, 14:57

Hello everyone!

I love the cheap Pro Micro to do custom keyboards.

But it only have 18 pins. I've done many keyboards in 5x13 matrix (65 keys), but I was wondering is "something" (electronical I guess) prevent me to use it as a 9x9 matrix to have more keys (81 keys) even if wire is more difficult.

TL;DR: Can I use a use a 9x9 matrix on Pro Micro to build 81 keys keyboard?

A big thanks in advance!

kokokoy · 02 Apr 2018, 15:06

You can do 10x10 with that even. Use the RX and TX Led. Did a TKL with caps lock led with it.

Narann · 02 Apr 2018, 15:19

Thanks! I'm even more happy to see someone succeed at it.

Just to be sure, are you saying I should unsold the LEDs and use the pins for it?

kokokoy · 02 Apr 2018, 15:30

Ooops. Their resistors was I should have said. But yeah just remove those (the 2 on the bottom of the leds) then you’re good to go.

Narann · 02 Apr 2018, 16:35

Thanks, I still need one last info. If I unsold the two vertical resistors, each one have two holes (one coming from the LED and the second from the other part of the circuit).

On my picture, which numbers would be the "new" pins? 1 and 3 or 2 and 4?

A big thanks in advance!

Narann · 02 Apr 2018, 16:38

If I rotate the Pro Micro shematic, I guess it's 2 and 4. Am I right?

kokokoy · 02 Apr 2018, 17:29

Haha. Sorry mate not familiar with circuit diagrams. I am a complete noob on the things and was totally winging it when I build my board.

But anyway you’re correct its 2 and 4. Lastly, just checked my board and it tirns out I didn’t even removed it (really remembered I did).

: 7586DE62-2B11-47B3-9330-3B7FF21AC44F.jpeg (375.78 KiB) Viewed 2477 times

Narann · 02 Apr 2018, 18:34

Wow thanks mate!

Haha, I see I'm not the only glue mess guy over here!

__red__ · 02 Apr 2018, 19:05

Suggestion - get yourself some UV-cured PCB mask. That hot-glue isn't going to protect the connection fully from stress.

https://www.ebay.com/itm/10ml-PCB-UV-Cu ... 1374454986