DCF-controlled LED clock:

Visitors to Germany may have seen the world’s largest digital clock which is housed in a 234 metres high transmitter tower on the banks of the Rhine in Düsseldorf. The time is indicated by vertically arranged lamps that shine their light through ‘portholes’ (glazed round windows). This article describes a miniature replica of this Rheinturmuhr (Rhine Tower Clock). It is controlled by an Atmel processor and synchronized by a DCF module.