This is the Smallest Binary Clock that show the time with just 4 leds.
The brain in this clock is PIC16F84A,The time will be displayed when the 'show' pushbutton is pressed. The digits of the time are displayed in BCD on the four LEDs. Tens of hours is displayed followed by hours, tens of minutes and then minutes.
Step 1: Parts
For this project you will need:
2.Crystal 32.768khz(you may find in ordinary clocks)
3.Four leds any color
4. Resistors 4x270 ohm
5. Ceramic cap 2x33 Pf
6. Push Buttons 3 peaces