[Hackrf-dev] HackRF support for Kalibrate.

[王康]

Hi guys,

I just added hackrf support for kalibrate.

You can find it on :

    https://github.com/scateu/kalibrate-hackrf

Kalibrate is a Linux program that uses GSM mobile cell phone base
stations to determine the PPM offset, by using the GSM signals own
frequency correction bursts(FCCH).

I think the code is working now, and any report or fix will be very welcomed.

$ ./kal -s GSM900
    hackrf_set_freq: 939400000
            chan: 22 (939.4MHz + 325Hz)     power: 474916.50
    hackrf_set_freq: 939600000
    hackrf_set_freq: 939800000
    hackrf_set_freq: 940000000
    hackrf_set_freq: 940200000
    hackrf_set_freq: 940400000
            chan: 27 (940.4MHz + 325Hz)     power: 503685.38
    hackrf_set_freq: 940600000
    hackrf_set_freq: 940800000
    hackrf_set_freq: 941000000
    hackrf_set_freq: 941200000
    hackrf_set_freq: 941400000
            chan: 32 (941.4MHz + 378Hz)     power: 450694.89
    hackrf_set_freq: 941600000
            chan: 33 (941.6MHz + 363Hz)     power: 450264.92
    hackrf_set_freq: 941800000
    hackrf_set_freq: 942000000

$ ./kal -c 32 -D
    debug: fcch_detector finished -----------------------------
    debug: error limit: 0.5
    debug: 146      272.215363      68025.585938
    [.......]
    debug: fcch_detector finished -----------------------------
    debug: error limit: 0.5
    debug: 144      290.700104      68040.851562
    debug: fcch_detector finished -----------------------------
    average         [min, max]      (range, stddev)
    + 326Hz         [291, 363]      (72, 19.584045)
    overruns: 0
    not found: 3
    average absolute error: -0.347 ppm


For now ,the code is quite dirty, I will make it clean later.

BTW:
I think we need some API function like:

    hackrf_read_sync(device, buf, sizeof(buf), &n_read)

Now I have to use hackrf_start_rx() with a callback function.



------------------------
Cheers,
scateu.
http://hackrf.net :  A Chinese HackRF Community.