| Electronics > Projects, Designs, and Technical Stuff |
| DCF77 PM receiver (radio clock) |
| << < (4/4) |
| capt bullshot:
--- Quote from: ogden on April 10, 2019, 12:09:23 pm ---Your approach could need plenty of memory. dsPIC of mentioned project has 2KB RAM ;) --- End quote --- The dsPIC does the receiver part alone, not the decoder. So it's a nice and tidy PM receiver that outputs the demodulated time code. Of course, I've done DCF77 decoders in a few bytes (not kB) of RAM within an 8051, so one could most probably add a simple decoder to the dsPIC. No doubt one can do this using an STM32F3 too. The larger amount of RAM eases the implementation of the decoder having large buffers of received data to make use of the predictability of the time code to mitigate weak / distorted signal conditions. This would be significantly harder to implement with 8kB (or 2kB) of RAM. --- Quote ---Here is a link with a description of a digital DCF receiver i made using a HP E1430A VXI module. Written in German but you can probably use an automatic translator. http://www.cadt.de/dieter/dcf/Praezisionsfrequenzmessungen.pdf --- End quote --- Thanks, interesting reading. Especially the conclusion about the tuned antenna that acts like a swing that is flapping around in the breeze. Apparently, mine does that too, directly affecting the short term stability of the PPS and 10MHz outputs. |
| capt bullshot:
Hi folks, I've updated my project page: http://wunderkis.de/dcf-rcvr/ Some more effort went into this project, including building receivers on a PCB, optimizing and testing the firmware and getting some results observing their timing output stability. BTW: at the left hand side of the first picture, one might discover the GPSDO mady by forum member RoadRunner |
| Navigation |
| Message Index |
| Previous page |