Thermometer is based on PIC16F628 microcontroller which reads temperature data from DS1820 sensor. All three 7 segment indicators are connected to TPIC6B595 shift register.
Registers are able to drain current for LED indicators that are powered from 12V voltage. Temperature sensor is capable to rank values from 0 to 99.5ºC with 0.5ºC accuracy. No negative values (hopefully temperature value won’t drop below zero). Program code is written for CCS C compiler. Great source to learn how to read data through 1-wire and drive powerful 7 segment LED displays.