I2C

When a board needs to connect a few low-speed peripherals, the first problem is often not “how do we move more data?” but “how do we use fewer wires and fewer pins while still letting multiple chips work together?” Temperature sensors, EEPROMs, RTCs, and power-management chips are not high-throughput devices, but they all need to be accessed by the host. If every extra chip needs its own dedicated wire set, cost, routing, and packaging pressure rise quickly.