SDR Challenge at DEFCON - can not decode messages

[Michael]

I am learning bladeRF. I compiled and ran alice and bob programs from the Challenge (http://www.nuand.com/blog/sdr-challenge-at-defcon/). But I do not see any successfully decoded messages.

I use two bladeRFs. On one I run bob and on another one I run alice.

I slightly modified the source code (added printf and changed bob's sleep time to two seconds) and I see that decoded packet id (pkt.id) is always null.

The code of modified bob.c is here: http://pastebin.com/A54y0Uj4
Changes of bob.c:

Code: Select all

        pkt.prize = PRIZE_NONE;
 
        printf("packet: id = %d, prn = %d\n", pkt.id, pkt.prn); //here
        send_pkt(&pkt);
        send_pkt(&pkt);
 
        sleep(2); //and here

The code of modified alice.c is here: http://pastebin.com/TvUkxUH1
Changes:

Code: Select all

        if (pkt.id == pkt_id && pkt.prn == pkt_prn) {
            /* Enforce 5 minutes between victories */
            if (victory_time + 5 < time(NULL)) { //here
                pkt_id++;
                pkt_prn = rand();

The other changes are only adding printf.


Here is an example of alice.c output.

Code: Select all

First symbol of the first long synchronization pulse
len: 0
raw: 
Manchester:

Demanchester. len = 0:

Grouped binary:

Grouped binary in hex:
good = 1
☻packet: id = 0, prn = -1217376256 | pkt_id = 0, pkt_prn = 269070388
First symbol of the first long synchronization pulse
len: 0
raw: 
Manchester:

Demanchester. len = 0:

Grouped binary:

Grouped binary in hex:
good = 1
☻packet: id = 0, prn = -1217568768 | pkt_id = 0, pkt_prn = 269070388
First symbol of the first long synchronization pulse
len: 0
raw: 
Manchester:

Demanchester. len = 0:

Grouped binary:

Grouped binary in hex:
good = 1
☻packet: id = 0, prn = -1217568768 | pkt_id = 0, pkt_prn = 269070388

packet: id = 0, prn = -1217568768 - this values are from received packet.

What is going wrong?

[dave0160]

Michael,

Did you ever get this working? What OS and compiler are you using?

Dave

[Michael]

No, I failed to make this work.

I use Ubuntu 14.04 and gcc 4.8.2.