Hello,

I have implemented a similar plug-n-play I2C in one of my projects, although there is no possibility of Hot-pluggin/unplugging. I have 6 different I2C devices on the board which I provide empty sockets for particular I2C chips that are optionally used, and the firmware looks for a known list of devices at initialization. This works well.

Scanning 128 devices would be A. slow, B. managing different bus speeds (100 kHz, 400 kHz, 1 MHz) would be cumbersome and C. although the basic protocol is the same, the byte-level transactions are different for different devices.

As for hot-plug I2C, 10 second time-out is way too much. 10-100 mS is okay I suppose since it takes about 100 microseconds for a byte on the slowest 100 kHz I2C bus. Resetting the I2C bus (generating stop, start, pumping 9 bits and again start and stop condition) will get the bus into a known initial state again and the erring device may be removed from the list of active I2C devices.

Girish