OneWire Class in the Reference.
Espruino's 1-Wire API is designed to be similar to Arduino's OneWire library. Simply instantiate it with the pin to use, search for devices, and start communicating:
var ow = new OneWire(pin); device = ow.search(); // search returns an array of device IDs if (device===undefined) print("No OneWire devices found"); ow.reset(); ow.select(device); ow.write(42); var result = ow.read()
Note: OneWire devices need a 4.7kOhm pullup resistor on the data line in order to work correctly.
For examples of use, look in the source code for libraries that use OneWire...