A 100kHz I2C with a 10kOhm pullup resistor can only take like... 1nF of capacitance before it all falls apart. (Crude napkin math for RC constant equals 10uS, I'm probably off by a magnitude but I think I'm close).
We're talking about the physical wire and physical electricity. Eventually, the capacitance on the wire grows such that its literally impossible for a 100kHz wave (let alone a 200kHz or 1MHz wave) to be placed upon the wire.
Parasitic Capacitance is real. Each item you add in parallel to a bus will increase capacitance.
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Each item you add in serial to a bus will increase resistance and inductance, which also slows down the speed of the bus. Once the speed drops below the specified protocol (ex: 100kHz or whatever you've chosen), it all goes to crap and no one can talk anymore. I don't quite remember the napkin-math formulas for LRC-circuits but... parasitics are hugely important and nH of inductance and nC of parasitic capacitance absolutely can be reached with just a few connectors.
Honestly, I think the earlier estimate of "failing by a hundred connectors" is rather optimistic still. 100kHz I2C and 10kOhm pullup would probably fail within a dozen connectors.
You can have as much addressing as you like and software going on in the background. It don't matter if your literal wires no longer work as you expect.
A 100kHz I2C with a 10kOhm pullup resistor can only take like... 1nF of capacitance before it all falls apart. (Crude napkin math for RC constant equals 10uS, I'm probably off by a magnitude but I think I'm close).
We're talking about the physical wire and physical electricity. Eventually, the capacitance on the wire grows such that its literally impossible for a 100kHz wave (let alone a 200kHz or 1MHz wave) to be placed upon the wire.
Parasitic Capacitance is real. Each item you add in parallel to a bus will increase capacitance.
--------
Each item you add in serial to a bus will increase resistance and inductance, which also slows down the speed of the bus. Once the speed drops below the specified protocol (ex: 100kHz or whatever you've chosen), it all goes to crap and no one can talk anymore. I don't quite remember the napkin-math formulas for LRC-circuits but... parasitics are hugely important and nH of inductance and nC of parasitic capacitance absolutely can be reached with just a few connectors.
Honestly, I think the earlier estimate of "failing by a hundred connectors" is rather optimistic still. 100kHz I2C and 10kOhm pullup would probably fail within a dozen connectors.
You can have as much addressing as you like and software going on in the background. It don't matter if your literal wires no longer work as you expect.