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geekhack Projects => Making Stuff Together! => Topic started by: __red__ on Mon, 16 January 2017, 17:49:03

Title: DIP IC for USB keyboard scanning and encoding to PS/2 & USB...
Post by: __red__ on Mon, 16 January 2017, 17:49:03

Came across this on my travels, not sure if anyone else has seen it or would find it useful but...

http://www.farnell.com/datasheets/79209.pdf

$2.50 in quantities of 1.

Could be shiny for some of those wire-wrap boards we see from time to time.

Peace, love etc etc....



__red__

Title: Re: DIP IC for USB keyboard scanning and encoding to PS/2 & USB...
Post by: Findecanor on Tue, 17 January 2017, 02:33:21

There are a few IC's out there like it, but know this:

1. The matrix is hardwired in the controller, so you would have to wire it according to the layout in the datasheet!
You can't wire your keyboard the way that is easiest to do.
2. There is Phantom key detection that can't be disabled, and that means that it has 2-key rollover. Diodes would be useless.  From a quick look in the matrix, I can see that WASD should work but at least one surrounding key is blocked while holding down two off the WASD keys. There could also be a delay when you swap between W and S if A or D is held down simultaneously.
3. Low speed USB