W1: Geographical

The is usually no way to identify bus geometry
If you have several sensors, you can't know which is which
Thus, you usually only feature one device, or one per type
You can have one thermometer and one EEPROM
But I2C or SPI storage is much cheaper

Some devices offer extra pins to specify an "address"
You connect these to low or high level
The device status register is returning the value

In this case, you can match devices 
                         to their position
1 wire but many pins

Once I placed 20 of them in a board
4 gpio lines in total