Thread: KT2 Exposed
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Old 11-13-2014, 09:48 PM   #13
knc1
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Join Date: Feb 2012
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Device: No K1, PW2, KV, KOA
Quote:
Originally Posted by knc1 View Post
- - - - -
Added tech. sheet on switch chip.
The MicroFTX "cb" outputs are open-drain with a 75k ohm pull-up.
So far, the chip's I/O cells are referenced to 1v8 (since that matches the serial port I/O levels).
But the boot-mode lines need to be connected together (I am assuming here) to emulate a mechanical switch.
Plus, they are running on the 3v3 supply rail(s).

Hence, the added-in, switch chip.
And since they come in four per package ...
There are enough for all four "CB" outputs, if required by another project.
Hmm...
Use the four "CB" outputs as a 4-bit bus (possible with this adapter) -
Add 1-of-16 decoder -
Add as many as 16 buffer/driver/switches -

More than enough for every button on a K4 to be remote controlled over the USB-to-serial adapter.
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