DS18B20 1-Wire digital temperature sensor from Maxim IC has a range of –55°C to +125°C. Each sensor is uniquely addressable via a 64bit serial number so lots of sensors can be used on the same bus. Powered from 3v to 5.5V the sensor has up to 12bit resolution at ±0.5°C accuracy.
The tiny sensor has only 3 wires and uses only one wire for its "1-Wire® interface " and each sensor has a unique 64bit serial number. This means you can put a whole bunch of these little sensors on the same communications bus and read there values. See the documents section below for hookup guides and data sheets.
Unique 1-Wire® interface requires only one port pin for communication
Each device has a unique 64-bit serial code stored in an onboard ROM
Multidrop capability simplifies distributed temperature sensing applications
Requires no external components
Can be powered from data line. Power supply range is 3.0V to 5.5V
Measures temperatures from –55°C to +125°C (–67°F to +257°F)
±0.5°C accuracy from –10°C to +85°C
Thermometer resolution is user-selectable from 9 to 12 bits
Converts temperature to 12-bit digital word in 750ms (max.)
User-definable nonvolatile (NV) alarm settings
Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition)
Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system