1-Wire

In some device scenarios, the first engineering pain is not throughput, and not even many high-speed peripherals. It is that wiring itself is too expensive. Temperature probes may be spread out, a chassis may only tolerate a few wires, and a single controller may need to drive a few simple sensors. In that situation, even I2C’s two signal lines can feel like too many, let alone a dedicated chip-select line for each device.