Hi all, I am using GR 3.6.5.1 to receive BPSK modulated data from a third party RF chip / microcontroller combination and am having a strange experience. I am implementing a very simple protocol by constantly transmitting 0x7E constantly and then ASCII data triggered by a serial connection to the microcontroller, all at 9.6kbps
With the following configuration FCDPP source sampling at 192KHz. -> AGC -> Freq Xlate (bring near baseband) -> Costas loop (remove carrier) -> RRC (48 taps, symbol rate = 9600) -> PSK Demod (sps = 20 as 192/20 = 9.6kbps, everything else default) I can see my 0x7E bitstream "square wave" in a scope sink. When I pack the bits and send it to a file sink, I can see my 0x7E's and also ascii data that I've typed in to the microcontroller serial port. However - this is rare. Most of the time, I see the bytes of rotated flag - 0x3F, 0xFC, 0x3F etc. I thought this was ok, I can simply rotate the whole file by x bits to remake all the flags as 0x7E. But when I do this, my ascii text input is completely garbled, with only a few letters showing up. Can anyone give me a hint as to what is going on? I don't think my transmitter is the issue, as when I get my flag bytes in the output file, I can see my data. vanush _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
