USB-8451 chip select lines while talking I2C

[krugman3]

I intend to use the USB-8451 to communicate with a large number of I2C devices.

A power switching and monitoring device will contain a CAT9555 (An I2C DIO chip) and 3 x I2C current monitors.

there will be 64 of these power switching thingys.

I need some way of routing the I2C bus to the correct power switching thingy.

The DIO lines will be in use for over-current alarm inputs.

Could I use the API to put an address word on the SPI Chip Select lines even though I am not doing SPI communication?

I suspect that I could only drive one CS line at a time ?

Or would it be easier to just use a separate USB DIO ?

[Adam.B · Accepted solution]

Hi Krugman3,

If you're using the I2C I'm not sure you'll be able to use the SPI API at the same time as it might cause a device conflict, it might be easier to use seperate DIO.