This projects uses a single chip, PIC12F683 microcontroller, for temperature logging. A DS1820 sensor sends temperature value in digital format to PIC12F683 and it stores the value in to its internal EEPROM. The sampling interval for log can be selected from 1 sec, 1min, and 10 min using three tact switches.
The recorded temperature measurements can be downloaded to a PC through a serial interface. Read rest of the project.