Instructables
video One-Digit Clock
A real-time clock that uses only one 7-segment LED to display the time.  There are also four standard LEDs which tell you which digit you are looking at as the time is displayed.  Two IC chips are used to control the clock.

It uses an Atmega 168 Microcontroller chip (learned how to program it via Nerdkits.com) to control the displays and to interface with the timekeeping chip.  The timekeeping is done by the second chip, a DS-1302 Real-Time Clock chip.  One pushbutton is used to set the time.

The electronics are all hand-soldered.  There is a battery backup that maintains power to the timekeeping chip when AC power is not available.  Power is by a "wall wart" standard 5V DC transformer.

The clock is housed in a wooden case, made of spalted (partially rotten) birch and curly maple, from trees that I felled and cut into boards.



love it - more info though - schematics, etc. ?
again - good job!
amirm333 years ago
I really like this project.
very nice ideas in this minimalistic design - I liked the digit fade and the way you handle time setting.
I guess a count down timer wouldn't be too hard to add to it.
keith726 (author)  amirm333 years ago
Thank you - I am very proud of this project. It turned out very nice. What do you mean by a countdown timer?
RAULRO3 years ago
I LOVED, WOULD YOU POST THE SQUEMATIC AND CODE ?
IS VERY COOL !
CONGRAT, THANKS