The W1 kernel device driver allows you to control 1 Wire devices connected to GPIO 4.
The drivers are not loaded by default. See Loading Device Drivers.
The drivers can be loaded dynamically with:
modprobe wire modprobe w1_gpio modprobe w1_therm
The module HiPi::Device::OneWire gives simple read only access to the device driver functions.It is implemented primarily to support the HiPi::Interface::DS18X20 module that allows reading of the popular 18S20 and 18B20 temperature sensors.