The DS18B20 temperature sensor provides a 9 to 12 bit Centigrade temperature measurement and has an alarm function with non-volatile user-programmable upper and lower trigger points. It communicates over a 1-wire bus having a Data and Ground Line. Operating temperature range is -55 deg C to +125 deg C and is accurate to ±0.5 deg C over the range -10 deg C to +85 deg C. The DS18B20 can derive its power directly from the data line (IE Parasitically) eliminating the need for an external power supply. It has a unique 64-bit serial code which allows multiple units to function on the same 1-wire bus. The DS18B20 has a wired option (YSL18B20......) using Cat5 cable and terminating in a Plug (RJ45 or RJ11) that connects with your choice of 1-wire Host Adaptor. The device sits well with OWFS (One Wire File Server) and can be read remotely (using network and the 64-bit serial number as the Directory) using a PC or iPhone--there is a iPhone APP available which works well. The device has proven to work well on a Raspberry Pi using i2C to 1-Wire Host Adaptor, or Maxim/Dallas DS9490R USB Adaptor.