I was thinking about doing a modules for a development board I did a few days ago that will include spi/i2c interfaces.
The problem is that I didn't included pull-up resistors in the MCU pins in the main board and was thinking to add them in the modules to make them more "generic" so every user could use them without need to add extra resistors in the prototype board.
But then I faced the next problem. If I add the pull-up resistos in the extra modules and I connect for example two or more modules to the same bus I'll get those resistors in parallel so the resistance will drop and will not accomplish their function.
But if I add the pull-up resistors to the main board I'll have those pins in the MCU always as active low.
So the main question is:
How to have multiple modules connected to the same bus having on each of them the pull-up resistors but not get them in parallel when you've more than one module? Is that possible?
Or the best solution here is enable the pullup resistors in the MCU and don't inlcude them in the modules?