Hello Jeroen, 1/ So does your system actually use FreeDV 2400B? What does freedv_eth do?
2/ If possible, it would be much appreciated if you extend your work on freedv_codecrx() and freedv_codectx() to 700D. That might give Alan a good starting point for his project, as it would allow 700D codec bit stream to be received and transmitted again without the Codec 2 decoding step. Cheers, David On 14/07/18 23:42, Jeroen Vreeken wrote: > Hi All, > > While not a compleet parrot repeater yet, I might have some usefull > information. > Every Sunday a net is held at our local VHF repeater PI3EHV. > However due to interference some HAMs have difficulty receiving it (but > can transmit to it fine) and they made the request to use our UHF > repeater as they could hear it just fine. > I created a small DML node using a Raspberry Pi 3 and a Nicerf SA818V > module set to the frequency of PI2EHV. > On the DML network it makes the stream 'vhf.pe1rxq.ampr.org' available. > (It is fully capable of transmitting as well, but currently disabled due > to legal issues). Every sunday morning it automaticly connects to the > UHF repeater PI2EHV (the one I made a controller for last year) and for > a few hours audio received from PI3EHV is available on UHF. > > I just finished describing the setup and installation process here: > http://dmlinking.net/rpi3.html > It uses my freedv_eth program which uses the codec_tx and codec_rx > functions when transmitting/receiving in freedv mode. > In order to build a freedv parrot repeater you could use the same setup > with a few modifications: > - Set rx_mode and tx_mode to freedv (obviously) > - Connect a different radio (SSB capable) > - Link to a parrot reflector such as parrot.pe1rxq.ampr.org (9990) or > create a new one dedicated to freedv. > > There is a caveat at the moment though: I have not had time yet to > integrate the new 700D mode, it is capable of the 'older' modes though. > Also the signal detector (or squelch) is tuned for my 2400B setup, the > levels might need tweaking for other modes. > I plan to integrate 700D soon, it should be a nobrainer to add to > freedv_eth, and on first look it shouldn't be hard to modify the > codec_rx and codec_tx functions. > > If you don't use a Raspberry Pi most of the steps would still stay > pretty much the same. > > 73, > Jeroen > > > On 07/11/2018 01:52 AM, David Rowe wrote: >>> This is where I need help. Looking into "freedv_api.c" I can't find >>> where the ofdm_demod() >>> puts the data and thus how to do, what I want to do ie. remodulate so as >>> to have the error >>> correction done. I believe the data is in the structure type freedv "f". >> Our emails of 5 July describe how to extend freedv_codecrx() to support >> 700D. The demodulated and error corrected payload codec bits are placed >> into f->packed_codec_bits. >> >> They are then returned via the freedv_codecrx() to the caller. >> >> IIRC Jeroen did some work in this area and there are examples in >> freedv_tx.c and freedv_rx.c of sending data. Those unit tests would be >> a good place to test any changes. >> >> Or perhaps implement the parrot repeater using the 1600 modem or similar >> as a first step, as support exists for that in the freedv_api. >> >> - David >> >> ------------------------------------------------------------------------------ >> Check out the vibrant tech community on one of the world's most >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot >> _______________________________________________ >> Freetel-codec2 mailing list >> Freetel-codec2@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >> > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
