This project can be used to build Arduino shield to measure and display temperature.
-"Thermometer_precise.pde" sketch is revision of firmware with the most recent version of DallasTemperature library. (link is inside of the sketch) Tempereture resolution is raised up to 1/1000(3 digits after decimal point) of degree.
-Parts are now assembled on PCB produced by Fritzing Fab. (look at pictures)
I used DS18x20 sensor from Dallas components and HD44780-compatable LCD display. (part for Fritzing included LCD.fzpz) Temperature sensor uses one wire interface with parasite power. It requires one pull-up resistor (4.7K 0.25W) to get the power for temperature calculations and communication connected to +5V. With the same wire it connects to one digital pin on your Arduino board. Arduino Dallas Temperature library takes care of all conversions.
LCD is controlled with 4bit mode. On top of that interface has shift register 74HC595 to free up pins and get rid of several wires. Thus only 3 control wires are required. LCD3Wire library will do all the job (included in libraries.zip).
Screw-resistor 10KOhm is used to adjust brightness and contrast of your LCD.
PCB in Fritzing sketch is ready for production. (I didn´t spend much time on schematics, might be confusing...) Breadboard has couple of resistors, they mean nothing, used for nice place for jumper wires on pcb (I did not find jumper components accidentally...), this is it!