Introduction
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. In addition, the DS18B20 can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply. Datasheet.
Several different online shops sell the DS18B20 temperature sensor encased in watertight metal and with a waterproof cable. The one used in xspectrolum´s early spectrometers are from pchbutik.se. This version do not contain the 4.7 kOhm pull up resistor. Thus you must include that in the wiring, explained in the project page for the DS18B20 sensor.
