Taxi Meter Clocks
An old favorite, made from the display panel of a taxi meter (thanks, Bob!) The buttons set time as well as switch the display between time (hh:mm:ss), date (mm/dd/yy), and temperature. PIC 16F684 microcontroller, DS1307 RTC, DS1361 temp sensor.
Built around an extra taxi meter lens on hand. Uses a simple hh:mm clock chip from hightechips.com with built-in LED driver, a four-digit display, and is housed in a small cigar box that happened to fit the circuit board nicely.