The 1-wire interface is a protocol allowing a master to communicate with multiple slaves over a single wire. It uses a single pullup and open collector drivers with many of the slave device types getting their power from the pullup. Every slave device has a unique 64 bit registration number. 8 bits are a device type, 48 bits are a serial number and 8 bits are CRC.
The bit level protocol lets the master initiate all bits by pulling the line low. The master sends a zero or a one by holding the line down for longer or shorter times. When the master is reading a bit from a slave it pulls the line low for a minimum amount of time. The slave pulls the line low as well and after the master releases the line the slave determines the timing for the bit.
The higher level protocol allows the master to enumerate the devices on the bus. The master sends a command for all slaves to respond with their registration number. Each bit is read, the complement is read and the master then sends the value of the bit it is interested in. The slaves that match continue while the slaves that don't match stop outputting their configuration codes. By the time the entire configuration code is read, one unique code has been read identifying one device. The command is repeated until no new devices respond and all devices on the bus have been identified.
There are many device types. Some are just a serial number, others support EEPROM, RAM, keep time, measure temperature, control or sense an input signal and others.
I don't know the licensing arrangements Dallas has available. I have not seen any other companies making 1-wire devices. I have considered making my own 1-wire devices from 8 pin MCUs, mainly because their prices are a bit steep. I don't know if Dallas would take issue with that or not.
See http://www.aeolusdevelopment.com/Articles/download.html for an early port of the Maxim one-wire pd library to the LPC. Also LPC based boards that support it.
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