The DS18B20 digital thermometer provides 9-bit to 12-bit Celsius temperature measurements and has an alarm function with nonvolatile user programmable upper and lower trigger points. The DS18B20 communicates over  a  1-Wire bus that by definition requires only one data line (and ground) for communication with a central microprocessor. It has an operating temperature range of  -55°C to +125°C and is accurate to ±0.5°C over the range of  -10°C to +85°C. In addition, the DS18B20 can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply.


18B20 datasheet link


Maxim 1-Wire tutorial



Cheap and easy to assembly multiple connection 1-wire sensors over RS232 adapter. PC is interfaced with this hardware has been tested with standard serial port and with Profilic PL-2303 USB-to-Serial adapter in “parasite power” mode (no external power supply)





Projects based on 18B20 temperature sensors:


Denkovi USB to One Wire interface adaptor






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