1-Wire – introduction 1-Wire is a serial communications bus system developed by Dallas Semiconductor Corp (now Maxim Integrated Products, Inc.) It provides low-speed data, signaling, and power over a single line. 1-Wire is similar in concept to I²C, but with lower data rates and longer range. A typical network consists of a single master device connected to one or more slaves. Communication is bidirectional half-duplex, bit-sequential, with the LSB transmitted first. Speeds of 16 kbit/s Standard Mode, and 142 kbit/s Overdrive Mode are supported. Each slave is programmed with a unique ID, which allows configuration of multiple slave devices. The Master device can interrogate the network to discover what slave devices are connected and obtain their IDs. Communication is initiated and controlled by the Master, typically through an open drain bidirectional port pin. When idle the 1-Wire line is pulled up to the 3 V or 5 V supply voltage with a resistor. Most 1-Wire slave devices are parasitically powered. Power for device operation is derived from an internal power storage capacitor that stores charge when the 1-Wire line is in the idle high state. Communication is done with controlled short pulses, or “time slots”. PicoScope's serial decoding feature can decode 1-Wire data as well as over a dozen other protocols. More information on 1-Wire serial protocol decoding >>