using the DS18B20 sensors display 4*20 This is an electronic thermometer which has high accuracy over a wide range (accurate to ±0.5°C over the range of -10°C to +85°C) (Workable from -55°C to +125°C). You can locate these thermometer chips up to 100M away from your Arduino. Shorter cables can be just 2 wires. external image detail_134_ds18b20-3.jpg Multiple thermometers can be connected on the same wire because every one has it's own internal address. This is the "1-wire" bus system using this : •The updated "Dallas Temperature" Library •The updated "1-Wire" Library Wire library ... https://www.youtube.com/watch?v=q69PrpuyCFo