I2C Connections

Is I2C bus meant to be connected in daisy chain pattern, a star pattern, or it does matter and can use a combination?

star. Some modules have a feed through for the I2C lines. I use a few I2C devices simultaneously.

That's what confuses the issue. Feed through = daisy. Hence the question.

The "feedthrough is just an extension of the I2C lines.

If that is your idea of a daisy-chain, then it is also a daisy-chain.

Edit: My concept of a daisy-chain is where the first device output connects to the second device input.

As an example, I used 8 bit digital counter ICs. The first counter carry bit connected to the second counter input. When the first device was toggled from 255 to 0, the carry pin toggled, incrementing the second device. The first device was bits 0 to 7 of the count. The second device was bits 8 to 15. The clear pins were connected in a star.

My bad. I agree daisy chain is through a device. Trunk-line-drop-line is more descriptive of "feed through" that some I2C modules provide.

How would I2C handle a combination of star and Trunk-line-drop-line (from the feed through on those modules)? Anything to watch out for?

I know that I2C was originally for chip-to-chip on board communication. I'm looking at a project that will comprise a series of those pre-fab modules. In the enclosure some will be on the door, some on the back panel, and not all have the feed through. I'm trying to connect them all while minimizing the wiring. I can feed through all of the modules on the door (great!) but not all of the modules on the back panel.

It would be an 8 point start, with three device legs, four double device legs, and one five device leg (on the door).

Not that I'm aware of. All I2C devices I use are ok with the feedthrough lines.