What is the 1-Wire Bus?
The one-wire (1-Wire) bus is a half-duplex, single-master, multi-slave, asynchronous serial data bus designed to work with one wire only. In reality, for electrical reasons, the wires are at least two: one wire that carries a low-speed data signal with the power supply (data/power line) and the other one that is the ground (GND). However, despite this feature, most devices have three wires: the data signal, the GND, and the power supply (Vcc).
Tip
You should remember that half-duplex communication is when transmitting and receiving are not at the same time on the bus (the data can flow in one direction only), while asynchronous means that no clock is sent along with the data.
When a device has two wires only, it must include an in-built energy-storage mechanism (usually a capacitor) to store charge to power itself during periods when data is really exchanged. The device takes its power from the data pin instead of the regular power pin, and due to this reason, this...
