Wouter van Ooijen wrote:
> google 'dallas one-wire' or 'power line modem' (two very different
> approaches!).

1-wire uses one wire for data, one for ground and cannot carry power other than parasitic sourcing of remote 1-wire devices.

powerline modems are designed with AC-mains in mind.

To be more precise:
Max current 1A at 5V dc
Max datarate 1kbps
The circuit I am designing is very very space-constrained

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