Pr2-8 Input Pullup Option

Hardware
1

Noise
I’m using a pr16-4 relay board, Pr54-2 Featherlite IOT with Particle Photon2, Pr2-8 I/O.

I’m chasing a noise problem. With a standard volt meter, should I be able to measure pull-up voltage across the ground and input of the pr2-8 if my code is correct in activating the input pullup option? Thanks!

2

Yes, if pullups are active, you should be reading 5V

3

Okay, I see them at 5vdc or close to it.

I am using the DebounceSwitchRK and the MCP23008-RK from Rickkas7 Github.

I would like to use the interrupt rather than continuously polling on the I2C. It says the following:

When using interrupt mode, you need to associate a physical MCU pin as an interrupt pin
from the MCP23008 INT output.

Not sure what pin is available with the NCD Relay board and associated PR2-8 IO Boards.
If I am even understanding this correctly?

Thanks for any direction!

4

Yes, int is the best way to read an io.
the int is not exposed on the board.

5

Thanks so much for your reply.

So is this all done thru software to the MCP23008?

Could you point me just a bit further?

Thanks!