Filtering noise from a wire

[Demon]

what problem is the active pullup bus chip going to solve ? ...

I was hoping:

- it would allow me to use the MCP23017 at 400MHz,
- it would be enough to read rotary encoders with an MCP23017,
- it would work using I2CREAD command.

But that's too many IFs. The chip is not available in DIP package for me to test.

I've since decided to go with a dedicated 16F1937 TQFP-44 at 32MHz with 36 IOC pins to manage my encoders. I have room for 14 encoders on this secondary PIC (primary is a USB PIC), and the jumper at bottom right will permit me to use a 2nd circuit if needed in the future.

I only need 13 for this first project. I could use the 2 pins for encoder #14 to create a 3 bit jumper, giving me addressing for 8 circuits (total of 103 encoders). I'll most likely make the change now that I've thought about it.




EDIT: I didn't forgetting mounting holes. The PCB will be mounted vertically along the perimeter of the enclosure with the pins pointed inwards. The high-mounted header pins will be easy to access. and a single line of hot-glue will secure the connectors.