When the algorithm is started we do not know in which second we are, so we first must synchronize to the DCF77 signal. Текущая версия страницы пока не проверялась опытными участниками и может значительно отличаться от версии, проверенной 13 мая 2016; проверки требует 1 правка. There are many ways to deal with noise. The broadside must face in the direction of the transmitter.
With other words: the received signal is matched against an already known wave form. Unfortunately they have the most boring programming in Denmark, fish-prices, weather reports, notices to ships etc. This can easily be seen from the two txt files.
This holds true for all seconds but the last second of a minute. The program uses the SDL-library to acess the screen, this can be a problem when you don’t have HW-acceleration — I had to switch back to 16bpp on my X to get the required 20fps. The fifth timer expires in ~3000 ms. If it ever expires, we have lost reception. We set an error bit and stop the whole decoding process for some time. This problem is due to the evaluation of the parity bit. The time and date values are in BCD (Binary Coded Decimals) format. However, the clock frequencies fluctuate in the range of tens of ppm (part-per-million) and as a result the readings on different motes will drift over time.