Main Content

Using 2 ATmega328s, this clock displays and decodes the DCF77 signal using 150 LEDs and 4x 7 segment display modules on a 12” (305mm) dial.

This Clock displays the DCF77 time code on 2 rings of 60 LEDs on a large 12” (305mm) diameter dial. The inner ring shows the live time code for the next minute as it is received

and the outer ring shows the current time as long as the previous minute was received error free. A further 24 LEDs show decoder status and time info.

Decoded time and date are shown on 2 large 8 digit 7 segment displays while DCF77 pulse timings and bit information are shown on a further 2 smaller 8 digit 7 segment displays.

The clock uses 2 x Atmega 328 microprocessors (Arduino Uno) , 1 to control the DCF77 Analyzer and 1 to control a Udo Klein Super Filter.

The Super Filter allows advanced DCF77 signal processing and also tuning of the Arduino quartz crytal.

The filter is switchable and has 10 status LEDs to show the state of signal reception and quality of output.

The clock also chimes the hours, quarter hours and seconds tick through 2 off JQ6500 sound modules.”

Link to article