Freies Vortragsprogramm (Fr, 05.05.2006)

Decoding Time Signal Stations using OpenBSD

von Marc Balmer (micro systems)

Freitag, 05.05.2006, Saal 6.2, 16:00-17:00 Uhr

Time signal stations broadcast exact time information, usually using long-wave transmitters. Using a simple receiver and the right decoding software these time signal stations can be used to get accurate time information into the computer.

While the coding schemes vary from time signal station to time signal station, the decoding principles are similar.

I first give an overview of available time signal stations and the codes they use to transmit time information. I will then detail the coding scheme of the DCF77 time signal station that emits it's signal from Mainflingen near Frankfurt and which can be received all over Germany/Switzerland with a relatively cheap receiver.

I will show an example implementation of a device driver for OpenBSD that precisely decodes the time information using USB and serially attached receivers.

Über den Autor Marc Balmer:

Marc Balmer was born in 1968 in Basel, Switzerland. After going throught the usual education, he worked for Atari where he was in charge of Unix systems, Transputers and the OS-9 realtime operating system. In 1990 founded the swiss technology company micro systems which specialises in consulting, development and outsourcing services in the Unix domain.

He is an OpenBSD committer since 2004 and uses OpenBSD mostly for his work.

He has more than 20 years experience with Unix.